FluidIoC.js

/*
Copyright 2011-2013 OCAD University
Copyright 2010-2011 Lucendo Development Ltd.

Licensed under the Educational Community License (ECL), Version 2.0 or the New
BSD license. You may not use this file except in compliance with one these
Licenses.

You may obtain a copy of the ECL 2.0 License and BSD License at
https://github.com/fluid-project/infusion/raw/master/Infusion-LICENSE.txt
*/

// Declare dependencies
/*global fluid_1_5:true, jQuery*/

// JSLint options
/*jslint white: true, funcinvoke: true, continue: true, elsecatch: true, operator: true, jslintok:true, undef: true, newcap: true, regexp: true, bitwise: true, browser: true, forin: true, maxerr: 1000, indent: 4 */

var fluid_1_5 = fluid_1_5 || {};

(function ($, fluid) {

    /** The Fluid "IoC System proper" - resolution of references and
     * completely automated instantiation of declaratively defined
     * component trees */

    // unsupported, non-API function
    // Currently still uses manual traversal - once we ban manually instantiated components,
    // it will use the instantiator's records instead.
    fluid.visitComponentChildren = function (that, visitor, options, path, i) {
        var instantiator = fluid.getInstantiator(that);
        for (var name in that) {
            var newPath = instantiator.composePath(path, name);
            var component = that[name];
            // Every component *should* have an id, but some clients (e.g. DOM binder) may not yet be compliant
            // This entire algorithm is primitive and expensive and will be removed once we can abolish manual init components
            if (!component || !component.typeName || (component.id && options.visited && options.visited[component.id])) {continue; }
            if (options.visited) {
                options.visited[component.id] = true;
            }
            if (visitor(component, name, newPath, path, i)) {
                return true;
            }
            if (!options.flat) {
                fluid.visitComponentChildren(component, visitor, options, newPath);
            }
        }
    };

    // unsupported, non-API function
    fluid.getMemberNames = function (instantiator, thatStack) {
        var path = instantiator.idToPath(thatStack[thatStack.length - 1].id);
        var segs = fluid.model.parseEL(path);
        segs.unshift.apply(segs, fluid.generate(thatStack.length - segs.length, ""));
        return segs;
    };

    // thatStack contains an increasing list of MORE SPECIFIC thats.
    // this visits all components starting from the current location (end of stack)
    // in visibility order up the tree.
    var visitComponents = function (instantiator, thatStack, visitor, options) {
        options = options || {
            visited: {},
            flat: true,
            instantiator: instantiator
        };
        var memberNames = fluid.getMemberNames(instantiator, thatStack);
        for (var i = thatStack.length - 1; i >= 0; --i) {
            var that = thatStack[i], path;
            if (that.typeName) {
                options.visited[that.id] = true;
                path = instantiator.idToPath[that.id];
                if (visitor(that, memberNames[i], path, path, i)) {
                    return;
                }
            }
            if (fluid.visitComponentChildren(that, visitor, options, path, i)) {
                return;
            }
        }
    };

    fluid.mountStrategy = function (prefix, root, toMount, targetPrefix) {
        var offset = prefix.length;
        return function (target, name, i, segs) {
            if (i <= prefix.length) { // Avoid OOB to not trigger deoptimisation!
                return;
            }
            for (var j = 0; j < prefix.length; ++ j) {
                if (segs[j] !== prefix[j]) {
                    return;
                }
            }
            return toMount(target, name, i - prefix.length, segs.slice(offset));
        };
    };

    // unsupported, NON-API function
    fluid.invokerFromRecord = function (invokerec, name, that) {
        fluid.pushActivity("makeInvoker", "beginning instantiation of invoker with name %name and record %record as child of %that",
            {name: name, record: invokerec, that: that});
        var invoker = fluid.makeInvoker(that, invokerec, name);
        fluid.popActivity();
        return invoker;
    };

    // unsupported, NON-API function
    fluid.memberFromRecord = function (memberrec, name, that) {
        var value = fluid.expandOptions(memberrec, that);
        return value;
    };

    // unsupported, NON-API function
    fluid.recordStrategy = function (that, options, optionsStrategy, recordPath, recordMaker, prefix) {
        prefix = prefix || [];
        return {
            strategy: function (target, name, i, segs) {
                if (i !== 1) {
                    return;
                }
                var record = fluid.driveStrategy(options, [recordPath, name], optionsStrategy);
                if (record === undefined) {
                    return;
                }
                fluid.set(target, [name], fluid.inEvaluationMarker);
                var member = recordMaker(record, name, that);
                fluid.set(target, [name], member);
                return member;
            },
            initter: function () {
                var records = fluid.driveStrategy(options, recordPath, optionsStrategy) || {};
                for (var name in records) {
                    fluid.getForComponent(that, prefix.concat([name]));
                }
            }
        };
    };

    // patch Fluid.js version for timing
    // unsupported, NON-API function
    fluid.instantiateFirers = function (that, options) {
        var shadow = fluid.shadowForComponent(that);
        var initter = fluid.get(shadow, ["eventStrategyBlock", "initter"]) || fluid.identity;
        initter();
    };

    // unsupported, NON-API function
    fluid.makeDistributionRecord = function (contextThat, sourceRecord, sourcePath, targetSegs, exclusions, offset, sourceType) {
        offset = offset || 0;
        sourceType = sourceType || "distribution";

        var source = fluid.copy(fluid.get(sourceRecord, sourcePath));
        fluid.each(exclusions, function (exclusion) {
            fluid.model.applyChangeRequest(source, {path: exclusion, type: "DELETE"});
        });

        var record = {options: {}};
        var primitiveSource = fluid.isPrimitive(source);
        fluid.model.applyChangeRequest(record, {path: targetSegs, type: primitiveSource? "ADD": "MERGE", value: source});
        return $.extend(record, {contextThat: contextThat, recordType: sourceType, priority: fluid.mergeRecordTypes.distribution + offset});
    };

    // unsupported, NON-API function
    fluid.filterBlocks = function (contextThat, sourceBlocks, sourcePath, targetSegs, exclusions, removeSource) {
        var togo = [], offset = 0;
        fluid.each(sourceBlocks, function (block) {
            var source = fluid.get(block.source, sourcePath);
            if (source) {
                togo.push(fluid.makeDistributionRecord(contextThat, block.source, sourcePath, targetSegs, exclusions, offset++, block.recordType));
                var rescued = $.extend({}, source);
                if (removeSource) {
                    fluid.model.applyChangeRequest(block.source, {path: sourcePath, type: "DELETE"});
                }
                fluid.each(exclusions, function (exclusion) {
                    var orig = fluid.get(rescued, exclusion);
                    fluid.set(block.source, sourcePath.concat(exclusion), orig);
                });
            }
        });
        return togo;
    };

    // unsupported, NON-API function
    // TODO: This implementation is obviously poor and has numerous flaws
    fluid.matchIoCSelector = function (selector, thatStack, contextHashes, memberNames, i) {
        var thatpos = thatStack.length - 1;
        var selpos = selector.length - 1;
        while (true) {
            var mustMatchHere = thatpos === thatStack.length - 1 || selector[selpos].child;

            var that = thatStack[thatpos];
            var selel = selector[selpos];
            var match = true;
            for (var j = 0; j < selel.predList.length; ++j) {
                var pred = selel.predList[j];
                if (pred.context && !(contextHashes[thatpos][pred.context] || memberNames[thatpos] === pred.context)) {
                    match = false;
                    break;
                }
                if (pred.id && that.id !== pred.id) {
                    match = false;
                    break;
                }
            }
            if (selpos === 0 && thatpos > i && mustMatchHere) {
                match = false; // child selector must exhaust stack completely - FLUID-5029
            }
            if (match) {
                if (selpos === 0) {
                    return true;
                }
                --thatpos;
                --selpos;
            }
            else {
                if (mustMatchHere) {
                    return false;
                }
                else {
                    --thatpos;
                }
            }
            if (thatpos < i) {
                return false;
            }
        }
    };

    // unsupported, NON-API function
    fluid.collectDistributions = function (distributedBlocks, distribution, thatStack, contextHashes, memberNames, i) {
        if (fluid.matchIoCSelector(distribution.selector, thatStack, contextHashes, memberNames, i)) {
            distributedBlocks.push.apply(distributedBlocks, distribution.blocks);
        }
    };

    // unsupported, NON-API function
    fluid.receiveDistributions = function (parentThat, gradeNames, memberName) {
        var instantiator = fluid.getInstantiator(parentThat);
        var thatStack = instantiator.getThatStack(parentThat); // most specific is at end
        var memberNames = fluid.getMemberNames(instantiator, thatStack);
        memberNames.push(memberName);
        var distributedBlocks = [];
        var shadows = fluid.transform(thatStack, function (thisThat) {
            return instantiator.idToShadow[thisThat.id];
        });
        var contextHashes = fluid.getMembers(shadows, "contextHash");
        contextHashes.push(fluid.gradeNamesToHash(gradeNames));
        thatStack.push({}); // fake "that" since we try to match selectors before creation for FLUID-5013
        for (var i = 0; i < thatStack.length - 1; ++ i) {
            fluid.each(shadows[i].distributions, function (distribution) {
                fluid.collectDistributions(distributedBlocks, distribution, thatStack, contextHashes, memberNames, i);
            });
        }
        return distributedBlocks;
    };

    // unsupported, NON-API function
    fluid.applyDistributions = function (that, preBlocks, targetShadow) {
        var distributedBlocks = fluid.transform(preBlocks, function (preBlock) {
            return fluid.generateExpandBlock(preBlock, that, targetShadow.mergePolicy);
        });
        var mergeOptions = targetShadow.mergeOptions;
        mergeOptions.mergeBlocks.push.apply(mergeOptions.mergeBlocks, distributedBlocks);
        mergeOptions.updateBlocks();
    };

    // unsupported, NON-API function
    fluid.parseExpectedOptionsPath = function (path, role) {
        var segs = fluid.model.parseEL(path);
        if (segs.length > 1 && segs[0] !== "options") {
            fluid.fail("Error in options distribution record ", record, " - only " + role + " paths beginning with \"options\" are supported");
        }
        return segs.slice(1);
    };

    // unsupported, NON-API function
    fluid.isIoCSSSelector = function (context) {
        return context.indexOf(" ") !== -1; // simple-minded check for an IoCSS reference
    };

    // unsupported, NON-API function
    fluid.pushDistributions = function (targetHead, selector, blocks) {
        var targetShadow = fluid.shadowForComponent(targetHead);
        var id = fluid.allocateGuid();
        var distributions = (targetShadow.distributions = targetShadow.distributions || []);
        distributions.push({
            id: id,
            selector: selector,
            blocks: blocks
        });
        return id;
    };

    // unsupported, NON-API function
    fluid.clearDistributions = function (targetHead, id) {
        var targetShadow = fluid.shadowForComponent(targetHead);
        fluid.remove_if(targetShadow.distributions, function (distribution) {
            return distribution.id === id;
        });
    };

    // unsupported, NON-API function
    // Modifies a parsed selector to extra its head context which will be matched upwards
    fluid.extractSelectorHead = function (parsedSelector) {
        var predList = parsedSelector[0].predList;
        var context = predList[0].context;
        predList.length = 0;
        return context;
    };

    fluid.undistributableOptions = ["gradeNames", "distributeOptions", "returnedPath", "argumentMap", "initFunction", "mergePolicy", "progressiveCheckerOptions"]; // automatically added to "exclusions" of every distribution

    // unsupported, NON-API function
    fluid.distributeOptions = function (that, optionsStrategy) {
        var records = fluid.makeArray(fluid.driveStrategy(that.options, "distributeOptions", optionsStrategy));
        fluid.each(records, function (record) {
            var targetRef = fluid.parseContextReference(record.target);
            var targetComp, selector;
            if (fluid.isIoCSSSelector(targetRef.context)) {
                selector = fluid.parseSelector(targetRef.context, fluid.IoCSSMatcher);
                var headContext = fluid.extractSelectorHead(selector);
                if (headContext !== "that") {
                    fluid.fail("Downwards options distribution not supported from component other than \"that\"");
                }
                targetComp = that;
            }
            else {
                targetComp = fluid.resolveContext(targetRef.context, that);
                if (!targetComp) {
                    fluid.fail("Error in options distribution record ", record, " - could not resolve context selector {"+targetRef.context+"} to a root component");
                }
            }
            var targetSegs = fluid.model.parseEL(targetRef.path);
            var preBlocks;
            if (record.record) {
                preBlocks = [(fluid.makeDistributionRecord(that, record.record, [], targetSegs, [], 0))];
            }
            else {
                var thatShadow = fluid.shadowForComponent(that);
                var source = fluid.parseContextReference(record.source || "{that}.options");
                if (source.context !== "that") {
                    fluid.fail("Error in options distribution record ", record, " only a context of {that} is supported");
                }
                var sourcePath = fluid.parseExpectedOptionsPath(source.path, "source");
                var fullExclusions = fluid.makeArray(record.exclusions).concat(sourcePath.length === 0 ? fluid.undistributableOptions : []);

                var exclusions = fluid.transform(fullExclusions, function (exclusion) {
                    return fluid.model.parseEL(exclusion);
                });

                preBlocks = fluid.filterBlocks(that, thatShadow.mergeOptions.mergeBlocks, sourcePath, targetSegs, exclusions, record.removeSource);
                thatShadow.mergeOptions.updateBlocks(); // perhaps unnecessary
            }
            // TODO: inline material has to be expanded in its original context!

            if (selector) {
                fluid.pushDistributions(targetComp, selector, preBlocks);
            }
            else { // The component exists now, we must rebalance it
                var targetShadow = fluid.shadowForComponent(targetComp);
                fluid.applyDistributions(that, preBlocks, targetShadow);
            }
        });
    };

    // unsupported, NON-API function
    fluid.gradeNamesToHash = function (gradeNames) {
        var contextHash = {};
        fluid.each(gradeNames, function (gradeName) {
            contextHash[gradeName] = true;
            contextHash[fluid.computeNickName(gradeName)] = true;
        });
        return contextHash;
    };

    // unsupported, NON-API function
    fluid.cacheShadowGrades = function (that, shadow) {
        var contextHash = fluid.gradeNamesToHash(that.options.gradeNames);
        contextHash[that.nickName] = true;
        shadow.contextHash = contextHash;
    };

    // First sequence point where the mergeOptions strategy is delivered from Fluid.js - here we take care
    // of both receiving and transmitting options distributions
    // unsupported, NON-API function
    fluid.deliverOptionsStrategy = function (that, target, mergeOptions) {
        var shadow = fluid.shadowForComponent(that, shadow);
        fluid.cacheShadowGrades(that, shadow);
        shadow.mergeOptions = mergeOptions;
    };

    // unsupported, NON-API function
    fluid.resolveReturnedPath = function (returnedPath, that) {
        var shadow = fluid.shadowForComponent(that);
        // This prevents corruption of instantiator records by defeating effect of "returnedPath" for non-roots
        return shadow && shadow.path !== "" ? null : returnedPath;
    };

    // unsupported, NON-API function
    fluid.computeDynamicGrades = function (that, shadow, strategy) {
        delete that.options.gradeNames; // Recompute gradeNames for FLUID-5012 and others
        var gradeNames = fluid.driveStrategy(that.options, "gradeNames", strategy);

        // TODO: In complex distribution cases, a component might end up with multiple default blocks
        var defaultsBlock = fluid.findMergeBlocks(shadow.mergeOptions.mergeBlocks, "defaults")[0];
        var dynamicGrades = fluid.remove_if(gradeNames, function (gradeName) {
            return gradeName.charAt(0) === "{" || !fluid.hasGrade(defaultsBlock.target, gradeName);
        }, []);
        var resolved = [];
        fluid.each(dynamicGrades, function (dynamicGrade) {
            var func = fluid.expandOptions(dynamicGrade, that);
            resolved = resolved.concat(typeof(func) === "function" ? func() : func);
        });
        if (resolved.length !== 0) {
            var newDefaults = fluid.copy(fluid.getGradedDefaults(that.typeName, resolved));
            gradeNames.length = 0; // acquire derivatives of dynamic grades (FLUID-5054)
            gradeNames.push.apply(gradeNames, newDefaults.gradeNames);
            fluid.cacheShadowGrades(that, shadow);
            // This cheap strategy patches FLUID-5091 for now - some more sophisticated activity will take place
            // at this site when we have a full fix for FLUID-5028
            shadow.mergeOptions.destroyValue("components");

            var defaultsBlock = fluid.findMergeBlocks(shadow.mergeOptions.mergeBlocks, "defaults")[0];
            defaultsBlock.source = newDefaults;
            shadow.mergeOptions.updateBlocks();
        }
    };

    fluid.computeDynamicComponentKey = function (recordKey, sourceKey) {
        return recordKey + (sourceKey === 0 ? "" : "-" + sourceKey); // TODO: configurable name strategies
    };

    // unsupported, NON-API function
    fluid.registerDynamicRecord = function (that, recordKey, sourceKey, record, toCensor) {
        var key = fluid.computeDynamicComponentKey(recordKey, sourceKey);
        var cRecord = fluid.copy(record);
        delete cRecord[toCensor];
        fluid.set(that.options, ["components", key], cRecord);
        return key;
    };

    // unsupported, NON-API function
    fluid.computeDynamicComponents = function (that, mergeOptions) {
        var shadow = fluid.shadowForComponent(that);
        var localSub = shadow.subcomponentLocal = {};
        var records = fluid.driveStrategy(that.options, "dynamicComponents", mergeOptions.strategy);
        fluid.each(records, function (record, recordKey) {
            if (!record.sources && !record.createOnEvent) {
                fluid.fail("Cannot process dynamicComponents record ", record, " without a \"sources\" or \"createOnEvent\" entry");
            }
            if (record.sources) {
                var sources = fluid.expandOptions(record.sources, that);
                fluid.each(sources, function (source, sourceKey) {
                    var key = fluid.registerDynamicRecord(that, recordKey, sourceKey, record, "sources");
                    localSub[key] = {"source": source, "sourcePath": sourceKey};
                });
            }
            else if (record.createOnEvent) {
                var event = fluid.event.expandOneEvent(that, record.createOnEvent);
                fluid.set(shadow, ["dynamicComponentCount", recordKey], 0);
                var listener = function () {
                    var key = fluid.registerDynamicRecord(that, recordKey, shadow.dynamicComponentCount[recordKey]++, record, "createOnEvent");
                    localSub[key] = {"arguments": fluid.makeArray(arguments)};
                    fluid.initDependent(that, key);
                };
                event.addListener(listener);
                fluid.recordListener(event, listener, shadow);
            }
        });
    };

    // Second sequence point for mergeOptions from Fluid.js - here we construct all further
    // strategies required on the IoC side and mount them into the shadow's getConfig for universal use
    // unsupported, NON-API function
    fluid.computeComponentAccessor = function (that) {
        var shadow = fluid.shadowForComponent(that);
        var options = that.options;
        var strategy = shadow.mergeOptions.strategy;
        var optionsStrategy = fluid.mountStrategy(["options"], options, strategy);
        shadow.invokerStrategy = fluid.recordStrategy(that, options, strategy, "invokers", fluid.invokerFromRecord);
        shadow.eventStrategyBlock = fluid.recordStrategy(that, options, strategy, "events", fluid.eventFromRecord, ["events"]);
        var eventStrategy = fluid.mountStrategy(["events"], that, shadow.eventStrategyBlock.strategy, ["events"]);
        shadow.memberStrategy = fluid.recordStrategy(that, options, strategy, "members", fluid.memberFromRecord);
        // NB - ginger strategy handles concrete, rationalise
        shadow.getConfig = {strategies: [fluid.model.funcResolverStrategy, fluid.makeGingerStrategy(that),
            optionsStrategy, shadow.invokerStrategy.strategy, shadow.memberStrategy.strategy, eventStrategy]};

        fluid.computeDynamicGrades(that, shadow, strategy, shadow.mergeOptions.mergeBlocks);
        fluid.distributeOptions(that, strategy);

        return shadow.getConfig;
    };

    fluid.shadowForComponent = function (component) {
        var instantiator = fluid.getInstantiator(component);
        return instantiator && component ? instantiator.idToShadow[component.id] : null;
    };

    fluid.getForComponent = function (component, path) {
        var shadow = fluid.shadowForComponent(component);
        var getConfig = shadow ? shadow.getConfig : undefined;
        return fluid.get(component, path, getConfig);
    };

    // An EL segment resolver strategy that will attempt to trigger creation of
    // components that it discovers along the EL path, if they have been defined but not yet
    // constructed.
    // unsupported, NON-API function
    fluid.makeGingerStrategy = function (that) {
        var instantiator = fluid.getInstantiator(that);
        return function (component, thisSeg, index, segs) {
            var atval = component[thisSeg];
            if (atval === fluid.inEvaluationMarker && index === segs.length) {
                fluid.fail("Error in component configuration - a circular reference was found during evaluation of path segment \"" + thisSeg
                + "\": for more details, see the activity records following this message in the console, or issue fluid.setLogging(fluid.logLevel.TRACE) when running your application");
            }
            if (index > 1) {
                return atval;
            }
            if (atval === undefined) { // pick up components in instantiation here - we can cut this branch by attaching early
                var parentPath = instantiator.idToShadow[component.id].path;
                var childPath = fluid.composePath(parentPath, thisSeg);
                atval = instantiator.pathToComponent[childPath];
            }
            if (atval === undefined) {
                // TODO: This check is very expensive - once gingerness is stable, we ought to be able to
                // eagerly compute and cache the value of options.components - check is also incorrect and will miss injections
                if (fluid.getForComponent(component, ["options", "components", thisSeg])) {
                    fluid.initDependent(component, thisSeg);
                    atval = component[thisSeg];
                }
            }
            return atval;
        };
    };

    fluid.filterBuiltinGrades = function (gradeNames) {
        return fluid.remove_if(fluid.makeArray(gradeNames), function (gradeName) {
            return /autoInit|fluid.littleComponent|fluid.modelComponent|fluid.eventedComponent|fluid.viewComponent|fluid.typeFount/.test(gradeName);
        });
    };

    fluid.dumpGradeNames = function (that) {
        return that.options && that.options.gradeNames ?
            " gradeNames: " + JSON.stringify(fluid.filterBuiltinGrades(that.options.gradeNames)) : "";
    };

    // unsupported, non-API function
    fluid.dumpThat = function (that) {
        return "{ typeName: \"" + that.typeName + "\"" + fluid.dumpGradeNames(that) + " id: " + that.id + "}";
    };

    // unsupported, non-API function
    fluid.dumpThatStack = function (thatStack, instantiator) {
        var togo = fluid.transform(thatStack, function(that) {
            var path = instantiator.idToPath(that.id);
            return fluid.dumpThat(that) + (path? (" - path: " + path) : "");
        });
        return togo.join("\n");
    };

    var localRecordExpected = /arguments|options|container|source|sourcePath/;

    // unsupported, NON-API function
    fluid.resolveContext = function (context, that) {
        var instantiator = fluid.getInstantiator(that);
        if (context === "instantiator") {
            return instantiator;
        }
        else if (context === "that") {
            return that;
        }
        var foundComponent;
        var thatStack = instantiator.getFullStack(that);
        visitComponents(instantiator, thatStack, function (component, name) {
            var shadow = fluid.shadowForComponent(component);
            // TODO: Some components, e.g. the static environment and typeTags do not have a shadow, which slows us down here
            if (context === name || shadow && shadow.contextHash && shadow.contextHash[context] || context === component.typeName || context === component.nickName) {
                foundComponent = component;
                return true; // YOUR VISIT IS AT AN END!!
            }
            if (fluid.getForComponent(component, ["options", "components", context, "type"]) && !component[context]) {
  // This is an expensive guess since we make it for every component up the stack - must apply the WAVE OF EXPLOSION (FLUID-4925) to discover all components first
  // This line attempts a hopeful construction of components that could be guessed by nickname through finding them unconstructed
  // in options. In the near future we should eagerly BEGIN the process of constructing components, discovering their
  // types and then attaching them to the tree VERY EARLY so that we get consistent results from different strategies.
                foundComponent = fluid.getForComponent(component, context);
                return true;
            }
        });
        return foundComponent;
    };

    // unsupported, NON-API function
    fluid.makeStackFetcher = function (parentThat, localRecord) {
        var fetcher = function (parsed) {
            var context = parsed.context;
            if (localRecord && localRecordExpected.test(context)) {
                var fetched = fluid.get(localRecord[context], parsed.path);
                return context === "arguments" || context === "source" || context === "sourcePath" ? fetched : {
                    marker: context === "options" ? fluid.EXPAND : fluid.EXPAND_NOW,
                    value: fetched
                };
            }
            var foundComponent = fluid.resolveContext(context, parentThat);
            if (!foundComponent && parsed.path !== "") {
                var ref = fluid.renderContextReference(parsed);
                fluid.fail("Failed to resolve reference " + ref + " - could not match context with name "
                    + context + " from component " + fluid.dumpThat(parentThat), parentThat);
            }
            return fluid.getForComponent(foundComponent, parsed.path);
        };
        return fetcher;
    };

    // unsupported, NON-API function
    fluid.makeStackResolverOptions = function (parentThat, localRecord) {
        return $.extend(fluid.copy(fluid.rawDefaults("fluid.makeExpandOptions")), {
            fetcher: fluid.makeStackFetcher(parentThat, localRecord),
            contextThat: parentThat
        });
    };

    // unsupported, non-API function
    fluid.clearListeners = function (shadow) {
        fluid.each(shadow.listeners, function (rec) {
            rec.event.removeListener(rec.listener);
        });
        delete shadow.listeners;
    };

    // unsupported, non-API function
    fluid.recordListener = function (event, listener, shadow) {
        var listeners = shadow.listeners;
        if (!listeners) {
            listeners = shadow.listeners = [];
        }
        listeners.push({event: event, listener: listener});
    };

    var idToInstantiator = {};

    // unsupported, non-API function - however, this structure is of considerable interest to those debugging
    // into IoC issues. The structures idToShadow and pathToComponent contain a complete map of the component tree
    // forming the surrounding scope
    fluid.instantiator = function (freeInstantiator) {
        var that = {
            id: fluid.allocateGuid(),
            nickName: "instantiator",
            pathToComponent: {},
            idToShadow: {},
            composePath: fluid.composePath // For speed, we declare that no component's name may contain a period
        };
        // We frequently get requests for components not in this instantiator - e.g. from the dynamicEnvironment or manually created ones
        that.idToPath = function (id) {
            var shadow = that.idToShadow[id];
            return shadow ? shadow.path : "";
        };
        that.getThatStack = function (component) {
            var shadow = that.idToShadow[component.id];
            if (shadow) {
                var path = shadow.path;
                var parsed = fluid.model.parseEL(path);
                var togo = fluid.transform(parsed, function (value, i) {
                    var parentPath = fluid.model.composeSegments.apply(null, parsed.slice(0, i + 1));
                    return that.pathToComponent[parentPath];
                });
                var root = that.pathToComponent[""];
                if (root) {
                    togo.unshift(root);
                }
                return togo;
            }
            else { return [component];}
        };
        that.getEnvironmentalStack = function () {
            var togo = [fluid.staticEnvironment];
            if (!freeInstantiator) {
                togo.push(fluid.globalThreadLocal());
            }
            return togo;
        };
        that.getFullStack = function (component) {
            var thatStack = component? that.getThatStack(component) : [];
            return that.getEnvironmentalStack().concat(thatStack);
        };
        function recordComponent(component, path, created) {
            if (created) {
                idToInstantiator[component.id] = that;
                var shadow = that.idToShadow[component.id] = {};
                shadow.path = path;
            }
            if (that.pathToComponent[path]) {
                fluid.fail("Error during instantiation - path " + path + " which has just created component " + fluid.dumpThat(component)
                    + " has already been used for component " + fluid.dumpThat(that.pathToComponent[path]) + " - this is a circular instantiation or other oversight."
                    + " Please clear the component using instantiator.clearComponent() before reusing the path.");
            }
            that.pathToComponent[path] = component;
        }
        that.recordRoot = function (component) {
            if (component && component.id && !that.pathToComponent[""]) {
                recordComponent(component, "", true);
            }
        };
        that.recordKnownComponent = function (parent, component, name, created) {
            var parentPath = that.idToShadow[parent.id].path;
            var path = that.composePath(parentPath, name);
            recordComponent(component, path, created);
        };
        that.clearComponent = function (component, name, child, options, noModTree, path) {
            var record = that.idToShadow[component.id].path;
            // use flat recursion since we want to use our own recursion rather than rely on "visited" records
            options = options || {flat: true, instantiator: that};
            child = child || component[name];
            path = path || record;
            if (path === undefined) {
                fluid.fail("Cannot clear component " + name + " from component ", component,
                    " which was not created by this instantiator");
            }
            fluid.fireEvent(child, "events.onClear", [child, name, component]);

            var childPath = that.composePath(path, name);
            var childRecord = that.idToShadow[child.id];

            // only recurse on components which were created in place - if the id record disagrees with the
            // recurse path, it must have been injected
            if (childRecord && childRecord.path === childPath) {
                fluid.fireEvent(child, "events.onDestroy", [child, name, component]);
                fluid.clearListeners(childRecord);
                fluid.visitComponentChildren(child, function(gchild, gchildname, newPath, parentPath) {
                    that.clearComponent(child, gchildname, null, options, true, parentPath);
                }, options, childPath);
                delete that.idToShadow[child.id];
                delete idToInstantiator[child.id];
            }
            delete that.pathToComponent[childPath]; // there may be no entry - if created informally
            if (!noModTree) {
                delete component[name]; // there may be no entry - if creation is not concluded
            }
        };
        return that;
    };

    // An instantiator to be used in the "free environment", unattached to any component tree
    fluid.freeInstantiator = fluid.instantiator(true);

    // Look up the globally registered instantiator for a particular component
    fluid.getInstantiator = function (component) {
        return component && idToInstantiator[component.id] || fluid.freeInstantiator;
    };

    /** Expand a set of component options either immediately, or with deferred effect.
     *  The current policy is to expand immediately function arguments within fluid.embodyDemands which are not the main options of a
     *  component. The component's own options take <code>{defer: true}</code> as part of
     *  <code>outerExpandOptions</code> which produces an "expandOptions" structure holding the "strategy" and "initter" pattern
     *  common to ginger participants.
     *  Probably not to be advertised as part of a public API, but is considerably more stable than most of the rest
     *  of the IoC API structure especially with respect to the first arguments.
     */

    fluid.expandOptions = function (args, that, mergePolicy, localRecord, outerExpandOptions) {
        if (!args) {
            return args;
        }
        fluid.pushActivity("expandOptions", "expanding options %args for component %that ", {that: that, args: args});
        var expandOptions = fluid.makeStackResolverOptions(that, localRecord);
        expandOptions.mergePolicy = mergePolicy;
        var expanded = outerExpandOptions && outerExpandOptions.defer ?
            fluid.makeExpandOptions(args, expandOptions) : fluid.expand(args, expandOptions);
        fluid.popActivity();
        return expanded;
    };

    // unsupported, non-API function
    fluid.localRecordExpected = ["type", "options", "args", "mergeOptions", "createOnEvent", "priority", "recordType"]; // last element unavoidably polluting
    // unsupported, non-API function
    fluid.checkComponentRecord = function (defaults, localRecord) {
        var expected = fluid.arrayToHash(fluid.localRecordExpected);
        fluid.each(defaults && defaults.argumentMap, function(value, key) {
            expected[key] = true;
        });
        fluid.each(localRecord, function (value, key) {
            if (!expected[key]) {
                fluid.fail("Probable error in subcomponent record - key \"" + key +
                    "\" found, where the only legal options are " +
                    fluid.keys(expected).join(", "));
            }
        });
    };

    // unsupported, non-API function
    fluid.pushDemands = function (list, demands) {
        demands = fluid.makeArray(demands);
        var thisp = fluid.mergeRecordTypes.demands;
        function push(rec) {
            rec.recordType = "demands";
            rec.priority = thisp++;
            list.push(rec);
        }
        // Assume these are sorted at source by intersect count (can't pre-merge if we want "mergeOptions")
        for (var i = 0; i < demands.length; ++ i) {
            var thisd = demands[i];
            if (thisd.options) {
                push(thisd);
            }
            else if (thisd.mergeOptions) {
                var mergeOptions = fluid.makeArray(thisd.mergeOptions);
                fluid.each(mergeOptions, function (record) { push ({options: record}); });
            }
            else {
                fluid.fail("Uninterpretable demands record without options or mergeOptions ", thisd);
            }
        }
    };

    // unsupported, non-API function
    fluid.mergeRecordsToList = function (mergeRecords) {
        var list = [];
        fluid.each(mergeRecords, function (value, key) {
            value.recordType = key;
            if (key === "distributions") {
                list.push.apply(list, value);
            }
            else if (key !== "demands") {
                if (!value.options) { return; }
                value.priority = fluid.mergeRecordTypes[key];
                if (value.priority === undefined) {
                    fluid.fail("Merge record with unrecognised type " + key + ": ", value);
                }
                list.push(value);
            }
            else {
                fluid.pushDemands(list, value);
            }
        });
        return list;
    };

    // TODO: overall efficiency could huge be improved by resorting to the hated PROTOTYPALISM as an optimisation
    // for this mergePolicy which occurs in every component. Although it is a deep structure, the root keys are all we need
    var addPolicyBuiltins = function (policy) {
        fluid.each(["gradeNames", "mergePolicy", "argumentMap", "components", "dynamicComponents", "members", "invokers", "events", "listeners", "distributeOptions", "transformOptions"], function (key) {
            fluid.set(policy, [key, "*", "noexpand"], true);
        });
        return policy;
    };

    // unsupported, NON-API function - used from Fluid.js
    fluid.generateExpandBlock = function (record, that, mergePolicy, localRecord) {
        var expanded = fluid.expandOptions(record.options, record.contextThat || that, mergePolicy, localRecord, {defer: true});
        expanded.priority = record.priority;
        expanded.recordType = record.recordType;
        return expanded;
    };

    var expandComponentOptionsImpl = function (mergePolicy, defaults, userOptions, that) {
        var defaultCopy = fluid.copy(defaults);
        addPolicyBuiltins(mergePolicy);
        var shadow = fluid.shadowForComponent(that);
        shadow.mergePolicy = mergePolicy;
        var mergeRecords = {
            defaults: {options: defaultCopy}
        };

        if (userOptions) {
            if (userOptions.marker === fluid.EXPAND) {
                $.extend(mergeRecords, userOptions.mergeRecords);
                // Do this here for gradeless components that were corrected by "localOptions"
                if (mergeRecords.subcomponentRecord) {
                    fluid.checkComponentRecord(defaults, mergeRecords.subcomponentRecord);
                }
            }
            else {
                mergeRecords.user = {options: userOptions};
            }
        }
        var expandList = fluid.mergeRecordsToList(mergeRecords);

        var togo = fluid.transform(expandList, function (value) {
            return fluid.generateExpandBlock(value, that, mergePolicy, userOptions && userOptions.localRecord);
        });
        return togo;
    };

    // unsupported, non-API function
    fluid.makeIoCRootDestroy = function (instantiator, that) {
        return function () {
            instantiator.clearComponent(that, "", that, null, true);
            fluid.fireEvent(that, "events.onDestroy", [that, "", null]);
        };
    };

    // unsupported, non-API function
    fluid.expandComponentOptions = function (mergePolicy, defaults, userOptions, that) {
        var instantiator = userOptions && userOptions.marker === fluid.EXPAND && userOptions.memberName !== undefined ?
            userOptions.instantiator : null;
        var fresh;
        if (!instantiator) {
            instantiator = fluid.instantiator();
            fresh = true;
            fluid.log("Created new instantiator with id " + instantiator.id + " in order to operate on component " + (that? that.typeName : "[none]"));
            that.destroy = fluid.makeIoCRootDestroy(instantiator, that);
        }
        fluid.pushActivity("expandComponentOptions", "expanding component options %options with record %record for component %that",
            {options: userOptions && userOptions.mergeRecords, record: userOptions, that: that});
        if (fresh) {
            instantiator.recordRoot(that);
        }
        else {
            instantiator.recordKnownComponent(userOptions.parentThat, that, userOptions.memberName, true);
        }
        var togo = expandComponentOptionsImpl(mergePolicy, defaults, userOptions, that);
        fluid.popActivity();
        return togo;
    };

    // unsupported, non-API function
    fluid.argMapToDemands = function (argMap) {
        var togo = [];
        fluid.each(argMap, function (value, key) {
            togo[value] = "{" + key + "}";
        });
        return togo;
    };

    // unsupported, non-API function
    fluid.makePassArgsSpec = function (initArgs) {
        return fluid.transform(initArgs, function(arg, index) {
            return "{arguments}." + index;
        });
    };

    // unsupported, NON-API function
    fluid.pushDemandSpec = function (record, options, mergeOptions) {
        if (options && options !== "{options}") {
            record.push({options: options});
        }
        if (mergeOptions) {
            record.push({mergeOptions: mergeOptions});
        }
    };

    /** Given a concrete argument list and/or options, determine the final concrete
     * "invocation specification" which is coded by the supplied demandspec in the
     * environment "thatStack" - the return is a package of concrete global function name
     * and argument list which is suitable to be executed directly by fluid.invokeGlobalFunction.
     */
    // unsupported, non-API function
    // options is just a disposition record containing memberName, componentRecord + passArgs
    // various built-in effects of this method
    // i) note that it makes no effort to actually propagate direct
    // options from "initArgs", assuming that they will be seen again in expandComponentOptions
    fluid.embodyDemands = function (parentThat, demandspec, initArgs, options) {
        options = options || {};

        if (demandspec.mergeOptions && demandspec.options) {
            fluid.fail("demandspec ", demandspec,
                    " is invalid - cannot specify literal options together with mergeOptions");
        }
        if (demandspec.transformOptions) { // Support for "transformOptions" at top level in a demands record
            demandspec.options = $.extend(true, {}, demandspec.options, {
                transformOptions: demandspec.transformOptions
            });
        }
        var demands = fluid.makeArray(demandspec.args);

        var upDefaults = fluid.defaults(demandspec.funcName);

        var distributions = upDefaults && parentThat ? fluid.receiveDistributions(parentThat, upDefaults.gradeNames, options.memberName) : [];

        var argMap = upDefaults? upDefaults.argumentMap : null;
        var inferMap = false;
        if (!argMap && (upDefaults || (options && options.componentRecord)) && !options.passArgs) {
            inferMap = true;
            // infer that it must be a little component if we have any reason to believe it is a component
            if (demands.length < 2) {
                argMap = fluid.rawDefaults("fluid.littleComponent").argumentMap;
            }
            else {
                var optionpos = $.inArray("{options}", demands);
                if (optionpos === -1) {
                    optionpos = demands.length - 1; // wild guess in the old style
                }
                argMap = {options: optionpos};
            }
        }
        options = options || {};
        if (demands.length === 0) {
            if (argMap) {
                demands = fluid.argMapToDemands(argMap);
            }
            else if (options.passArgs) {
                demands = fluid.makePassArgsSpec(initArgs);
            }
        }
        var shadow = fluid.shadowForComponent(parentThat);
        var localDynamic = shadow && options.memberName ? shadow.subcomponentLocal[options.memberName] : null;

        // confusion remains with "localRecord" - it is a random mishmash of user arguments and the component record
        // this should itself be absorbed into "mergeRecords" and let stackFetcher sort it out
        var localRecord = $.extend({"arguments": initArgs}, fluid.censorKeys(options.componentRecord, ["type"]), localDynamic);

        fluid.each(argMap, function (index, name) {
            // this is incorrect anyway! What if the supplied arguments were not in the same order as the target argmap,
            // which was obtained from the target defaults
            if (initArgs.length > 0) {
                localRecord[name] = localRecord["arguments"][index];
            }
            if (demandspec[name] !== undefined && localRecord[name] === undefined) {
                localRecord[name] = demandspec[name];
            }
            if (name !== "options") {
                for (var i = 0; i < distributions.length; ++ i) { // Apply non-options material from distributions (FLUID-5013)
                    if (distributions[i][name] !== undefined) {
                        localRecord[name] = distributions[i][name];
                    }
                }
            }
        });
        for (var i = 0; i < distributions.length; ++ i) {
            if (distributions[i].type !== undefined) {
                demandspec.funcName = distributions[i].type;
            }
        }

        var mergeRecords = {distributions: distributions};

        if (options.componentRecord !== undefined) {
            // Deliberately put too many things here so they can be checked in expandComponentOptions (FLUID-4285)
            mergeRecords.subcomponentRecord = $.extend({}, options.componentRecord);
        }
        var expandOptions = fluid.makeStackResolverOptions(parentThat, localRecord);
        var args = [];
        if (demands) {
            for (var i = 0; i < demands.length; ++i) {
                var arg = demands[i];
                // Weak detection since we cannot guarantee this material has not been copied
                if (fluid.isMarker(arg) && arg.value === fluid.COMPONENT_OPTIONS.value) {
                    arg = "{options}";
                    // Backwards compatibility for non-users of GRADES - last-ditch chance to correct the inference
                    if (inferMap) {
                        argMap = {options: i};
                    }
                }
                if (typeof(arg) === "string") {
                    if (arg.charAt(0) === "@") {
                        var argpos = arg.substring(1);
                        arg = "{arguments}." + argpos;
                    }
                }
                demands[i] = arg;
                if (!argMap || argMap.options !== i) {
                    // expand immediately if there can be no options or this is not the options
                    args[i] = fluid.expand(arg, expandOptions);
                }
                else { // It is the component options
                    if (typeof(arg) === "object" && !arg.targetTypeName) {
                        arg.targetTypeName = demandspec.funcName;
                    }
                    mergeRecords.demands = [];
                    fluid.each(demandspec.backSpecs.reverse(), function (backSpec) {
                        fluid.pushDemandSpec(mergeRecords.demands, backSpec.options, backSpec.mergeOptions);
                    });
                    fluid.pushDemandSpec(mergeRecords.demands, demandspec.options || arg, demandspec.mergeOptions);
                    if (initArgs.length > 0) {
                        mergeRecords.user = {options: localRecord.options};
                    }
                    args[i] = {marker: fluid.EXPAND,
                               localRecord: localDynamic,
                               mergeRecords: mergeRecords,
                               instantiator: fluid.getInstantiator(parentThat),
                               parentThat: parentThat,
                               memberName: options.memberName};
                }
                if (args[i] && fluid.isMarker(args[i].marker, fluid.EXPAND_NOW)) {
                    args[i] = fluid.expand(args[i].value, expandOptions);
                }
            }
        }
        else {
            args = initArgs? initArgs : [];
        }

        var togo = {
            args: args,
            preExpand: demands,
            funcName: demandspec.funcName
        };
        return togo;
    };

    // NON-API function
    fluid.fabricateDestroyMethod = function (that, name, instantiator, child) {
        return function () {
            instantiator.clearComponent(that, name, child);
        };
    };

    /** Instantiate the subcomponent with the supplied name of the supplied top-level component. Although this method
     * is published as part of the Fluid API, it should not be called by general users and may not remain stable. It is
     * currently the only mechanism provided for instantiating components whose definitions are dynamic, and will be
     * replaced in time by dedicated declarative framework described by FLUID-5022.
     * @param that {Component} the parent component for which the subcomponent is to be instantiated
     * @param name {String} the name of the component - the index of the options block which configures it as part of the
     * <code>components</code> section of its parent's options
     */
     // NB "directArgs" is now disused by the framework

    fluid.initDependent = function (that, name, directArgs) {
        if (that[name]) { return; } // TODO: move this into strategy
        directArgs = directArgs || [];
        var component = that.options.components[name];
        fluid.pushActivity("initDependent", "instantiating dependent component with name \"%name\" with record %record as child of %parent",
            {name: name, record: component, parent: that});
        var instance;
        var instantiator = idToInstantiator[that.id];

        if (typeof(component) === "string") {
            instance = fluid.expandOptions(component, that);
            instantiator.recordKnownComponent(that, instance, name, false);
        }
        else if (component.type) {
            var type = fluid.expandOptions(component.type, that);
            if (!type) {
                fluid.fail("Error in subcomponent record: ", component.type, " could not be resolved to a type for component ", name,
                    " of parent ", that);
            }
            var invokeSpec = fluid.resolveDemands(that, [type, name], directArgs,
                {componentRecord: component, memberName: name});
            instance = fluid.initSubcomponentImpl(that, {type: invokeSpec.funcName}, invokeSpec.args);
            // The existing instantiator record will be provisional, adjust it to take account of the true return
            // TODO: Instantiator contents are generally extremely incomplete
            var path = instantiator.composePath(instantiator.idToPath(that.id), name);
            var existing = instantiator.pathToComponent[path];
            // This branch deals with the case where the component creator registered a component into "pathToComponent"
            // that does not agree with the component which was the return value. We need to clear out "pathToComponent" but
            // not shred the component since most of it is probably still valid
            if (existing && existing !== instance) {
                instantiator.clearComponent(that, name, existing);
            }
            if (instance && instance.typeName && instance.id && instance !== existing) {
                instantiator.recordKnownComponent(that, instance, name, true);
            }
            instance.destroy = fluid.fabricateDestroyMethod(that, name, instantiator, instance);
        }
        else {
            fluid.fail("Unrecognised material in place of subcomponent " + name + " - no \"type\" field found");
        }
        that[name] = instance;
        fluid.fireEvent(instance, "events.onAttach", [instance, name, that]);
        fluid.popActivity();
        return instance;
    };

    // unsupported, non-API function
    fluid.bindDeferredComponent = function (that, componentName, component) {
        var events = fluid.makeArray(component.createOnEvent);
        fluid.each(events, function(eventName) {
            var event = eventName.charAt(0) === "{" ? fluid.expandOptions(eventName, that) : that.events[eventName];
            event.addListener(function () {
                fluid.pushActivity("initDeferred", "instantiating deferred component %componentName of parent %that due to event %eventName",
                 {componentName: componentName, that: that, eventName: eventName});
                if (that[componentName]) {
                    var instantiator = idToInstantiator[that.id];
                    instantiator.clearComponent(that, componentName);
                }
                fluid.initDependent(that, componentName);
                fluid.popActivity();
            }, null, null, component.priority);
        });
    };

    // unsupported, non-API function
    fluid.priorityForComponent = function (component) {
        return component.priority? component.priority :
            (component.type === "fluid.typeFount" || fluid.hasGrade(fluid.defaults(component.type), "fluid.typeFount"))?
            "first" : undefined;
    };

    fluid.initDependents = function (that) {
        fluid.pushActivity("initDependents", "instantiating dependent components for component %that", {that: that});
        var shadow = fluid.shadowForComponent(that);
        shadow.memberStrategy.initter();

        var options = that.options;
        var components = options.components || {};
        var componentSort = {};

        fluid.each(components, function (component, name) {
            if (!component.createOnEvent) {
                var priority = fluid.priorityForComponent(component);
                componentSort[name] = {key: name, priority: fluid.event.mapPriority(priority, 0)};
            }
            else {
                fluid.bindDeferredComponent(that, name, component);
            }
        });
        var componentList = fluid.event.sortListeners(componentSort);
        fluid.each(componentList, function (entry) {
            fluid.initDependent(that, entry.key);
        });

        shadow.invokerStrategy.initter();
        fluid.popActivity();
    };

    var dependentStore = {};

    function searchDemands (demandingName, contextNames) {
        var exist = dependentStore[demandingName] || [];
outer:  for (var i = 0; i < exist.length; ++i) {
            var rec = exist[i];
            for (var j = 0; j < contextNames.length; ++j) {
                if (rec.contexts[j] !== contextNames[j]) {
                    continue outer;
                }
            }
            return rec.spec; // jslint:ok
        }
    }

    var isDemandLogging = false;
    fluid.setDemandLogging = function (set) {
        isDemandLogging = set;
    };

    // unsupported, non-API function
    fluid.isDemandLogging = function (demandingNames) {
        return isDemandLogging && fluid.isLogging();
    };

    fluid.demands = function (demandingName, contextName, spec) {
        var contextNames = fluid.makeArray(contextName).sort();
        if (!spec) {
            return searchDemands(demandingName, contextNames);
        }
        else if (spec.length) {
            spec = {args: spec};
        }
        if (fluid.getCallerInfo && fluid.isDemandLogging()) {
            var callerInfo = fluid.getCallerInfo(5);
            if (callerInfo) {
                spec.registeredFrom = callerInfo;
            }
        }
        spec.demandId = fluid.allocateGuid();
        var exist = dependentStore[demandingName];
        if (!exist) {
            exist = [];
            dependentStore[demandingName] = exist;
        }
        exist.push({contexts: contextNames, spec: spec});
    };

    // unsupported, non-API function
    fluid.compareDemands = function (speca, specb) {
        return specb.intersect - speca.intersect;
    };

    // unsupported, non-API function
    fluid.locateAllDemands = function (parentThat, demandingNames) {
        var demandLogging = fluid.isDemandLogging(demandingNames);
        if (demandLogging) {
            fluid.log("Resolving demands for function names ", demandingNames, " in context of " +
                (parentThat? "component " + parentThat.typeName : "no component"));
        }

        var contextNames = {};
        var visited = [];
        var instantiator = fluid.getInstantiator(parentThat);
        var thatStack = instantiator.getFullStack(parentThat);
        visitComponents(instantiator, thatStack, function (component, xname, path, xpath, depth) {
            // NB - don't use shadow's cache here because we allow fewer names for demand resolution than for value resolution
            contextNames[component.typeName] = depth;
            var gradeNames = fluid.makeArray(fluid.get(component, ["options", "gradeNames"]));
            fluid.each(gradeNames, function (gradeName) {
                contextNames[gradeName] = depth;
            });
            visited.push(component);
        });
        if (demandLogging) {
            fluid.log("Components in scope for resolution:\n" + fluid.dumpThatStack(visited, instantiator));
        }
        var matches = [];
        for (var i = 0; i < demandingNames.length; ++i) {
            var rec = dependentStore[demandingNames[i]] || [];
            for (var j = 0; j < rec.length; ++j) {
                var spec = rec[j];
                var horizonLevel = spec.spec.horizon ? contextNames[spec.spec.horizon] : -1;
                var record = {spec: spec, intersect: 0, uncess: 0};
                for (var k = 0; k < spec.contexts.length; ++k) {
                    var depth = contextNames[spec.contexts[k]];
                    record[depth !== undefined && depth >= horizonLevel ? "intersect" : "uncess"] += 2;
                }
                if (spec.contexts.length === 0) { // allow weak priority for contextless matches
                    record.intersect++;
                }
                if (record.uncess === 0) {
                    matches.push(record);
                }
            }
        }
        matches.sort(fluid.compareDemands);
        return matches;
    };

    // unsupported, non-API function
    fluid.locateDemands = function (parentThat, demandingNames) {
        var matches = fluid.locateAllDemands(parentThat, demandingNames);
        var demandspec = fluid.getMembers(matches, ["spec", "spec"]);
        if (fluid.isDemandLogging(demandingNames)) {
            if (demandspec.length) {
                fluid.log("Located " + matches.length + " potential match" + (matches.length === 1? "" : "es") + ", selected best match with " + matches[0].intersect
                    + " matched context names: ", demandspec);
            }
            else {
                fluid.log("No matches found for demands, using direct implementation");
            }
        }
        return demandspec;
    };

    /** Determine the appropriate demand specification held in the fluid.demands environment
     * relative the supplied component position for the function name(s) funcNames.
     */
    // unsupported, non-API function
    fluid.determineDemands = function (parentThat, funcNames) {
        funcNames = fluid.makeArray(funcNames);
        var newFuncName = funcNames[0];
        var demandspec = fluid.locateDemands(parentThat, funcNames);
        if (demandspec.length && demandspec[0].funcName) {
            newFuncName = demandspec[0].funcName;
        }

        return $.extend(true, {funcName: newFuncName,
                                args: demandspec[0] ? fluid.makeArray(demandspec[0].args) : []
                                },
                                { backSpecs: demandspec.slice(1) }, // Fix for FLUID-5126
            fluid.censorKeys(demandspec[0], ["funcName", "args"]));
    };
    // "options" includes - passArgs, componentRecord, memberName (latter two from initDependent route)
    // unsupported, non-API function
    fluid.resolveDemands = function (parentThat, funcNames, initArgs, options) {
        var demandspec = fluid.determineDemands(parentThat, funcNames);
        return fluid.embodyDemands(parentThat, demandspec, initArgs, options);
    };

    // Convert a record which may harbour a "this/method" pair into an object which mocks the function.apply operation, pre-bound (for FLUID-4878)
    // unsupported, non-API function
    fluid.recordToApplicable = function (record, that) {
        var recthis = record["this"];
        if (record.method ^ recthis) {
            fluid.fail("Record ", that, " must contain both entries \"method\" and \"this\" if it contains either");
        }
        if (!record.method) {
            return null;
        }
        return {
            apply: function (noThis, args) {
                // Resolve this material late, to deal with cases where the target has only just been brought into existence
                // (e.g. a jQuery target for rendered material) - TODO: Possibly implement cached versions of these as we might do for invokers
                var resolvedThis = fluid.expandOptions(recthis, that);
                if (typeof(resolvedThis) === "string") {
                    resolvedThis = fluid.getGlobalValue(resolvedThis);
                }
                if (!resolvedThis) {
                    fluid.fail("Could not resolve reference " + recthis + " to a value");
                }
                var resolvedFunc = resolvedThis[record.method];
                if (typeof(resolvedFunc) !== "function") {
                    fluid.fail("Object ", resolvedThis, " at reference " + recthis + " has no member named " + record.method + " which is a function ");
                }
                fluid.log("Applying arguments ", args, " to method " + record.method + " of instance ", resolvedThis);
                return resolvedFunc.apply(resolvedThis, args);
            }
        };
    };

    // TODO: make a *slightly* more performant version of fluid.invoke that perhaps caches the demands
    // after the first successful invocation
    fluid.invoke = function (functionName, args, that, environment) {
        fluid.pushActivity("invokeFunc", "invoking function with name \"%functionName\" from component %that", {functionName: functionName, that: that});
        var invokeSpec = fluid.resolveDemands(that, functionName, fluid.makeArray(args), {passArgs: true});
        var togo = fluid.invokeGlobalFunction(invokeSpec.funcName, invokeSpec.args, environment);
        fluid.popActivity();
        return togo;
    };

    /** Make a function which performs only "static redispatch" of the supplied function name -
     * that is, taking only account of the contents of the "static environment". Since the static
     * environment is assumed to be constant, the dispatch of the call will be evaluated at the
     * time this call is made, as an optimisation.
     */
    // unsupported, non-API function
    fluid.makeFreeInvoker = function (functionName, environment) {
        var demandSpec = fluid.determineDemands(null, functionName);
        return function () {
            var invokeSpec = fluid.embodyDemands(null, demandSpec, fluid.makeArray(arguments), {passArgs: true});
            return fluid.invokeGlobalFunction(invokeSpec.funcName, invokeSpec.args, environment);
        };
    };
    
    var argPrefix = "{arguments}.";
    
    fluid.parseInteger = function (string) {
        return isFinite(string) && ((string % 1) === 0) ? Number(string) : NaN;
    };
    
    fluid.makeFastInvoker = function (invokeSpec, func) {
        var argMap;
        if (invokeSpec.preExpand) {
            argMap = {};
            for (var i = 0; i < invokeSpec.preExpand.length; ++ i) {
                var value = invokeSpec.preExpand[i];
                if (typeof(value) === "string") {
                    if (value === "{arguments}") {
                        argMap[i] = "*";
                    } else if (value.indexOf(argPrefix) === 0) {
                        var argIndex = fluid.parseInteger(value.substring(argPrefix.length));
                        if (isNaN(argIndex)) {
                            return {noFast: true}
                        }
                        else {
                            argMap[i] = argIndex; // target arg pos = original arg pos
                        }
                    }
                }
            }
        }
        var outArgs = invokeSpec.args;
        var invoke = argMap ? function invoke(args) {
            for (var i in argMap) {
                outArgs[i] = argMap[i] === "*" ? args : args[argMap[i]];
            }
            return func.apply(null, outArgs);
        } : function invoke (args) {
            return func.apply(null, args);
        };
        return {
            invoke: invoke
        };
    };

    // unsupported, non-API function
    fluid.makeInvoker = function (that, invokerec, name, environment) {
        var functionName;
        if (typeof(invokerec) === "string") {
            if (invokerec.charAt(0) === "{") { // shorthand case for direct function invokers (FLUID-4926)
                invokerec = {func: invokerec};
            } else {
                functionName = invokerec;
            }
        }
        var demandspec = functionName? fluid.determineDemands(that, functionName) : invokerec;
        var fastRec = {noFast: invokerec.dynamic};
        return function invokeInvoker () {
            if (fluid.defeatLogging === false) {
                fluid.pushActivity("invokeInvoker", "invoking invoker with name %name and record %record from component %that", {name: name, record: invokerec, that: that});
            }
            var togo;
            if (fastRec.invoke) {
                togo = fastRec.invoke(arguments);
            }
            else {
                var func = fluid.recordToApplicable(invokerec, that);
                var args = fluid.makeArray(arguments);
                var invokeSpec = fluid.embodyDemands(that, demandspec, args, {passArgs: true});
                func = func || (invokeSpec.funcName? fluid.getGlobalValue(invokeSpec.funcName, environment)
                    : fluid.expandOptions(demandspec.func, that));
                if (!func) {
                    fluid.fail("Error in invoker record: could not resolve members func, funcName or method to a function implementation", demandspec);
                }
                if (fastRec.noFast !== true) {
                    fastRec = fluid.makeFastInvoker(invokeSpec, func);
                }
                togo = func.apply(null, invokeSpec.args);
            }
            if (fluid.defeatLogging === false) {
                fluid.popActivity();
            }
            return togo;
        };
    };

    // unsupported, non-API function
    // weird higher-order function so that we can staightforwardly dispatch original args back onto listener
    fluid.event.makeTrackedListenerAdder = function (source) {
        var shadow = fluid.shadowForComponent(source);
        return function (event) {
            return {addListener: function (listener) {
                    fluid.recordListener(event, listener, shadow);
                    event.addListener.apply(null, arguments);
                }
            };
        };
    };

    // unsupported, non-API function
    fluid.event.listenerEngine = function (eventSpec, callback, adder) {
        var argstruc = {};
        function checkFire() {
            var notall = fluid.find(eventSpec, function(value, key) {
                if (argstruc[key] === undefined) {
                    return true;
                }
            });
            if (!notall) {
                var oldstruc = argstruc;
                argstruc = {}; // guard against the case the callback perversely fires one of its prerequisites (FLUID-5112)
                callback(oldstruc);
            }
        }
        fluid.each(eventSpec, function (event, eventName) {
            adder(event).addListener(function () {
                argstruc[eventName] = fluid.makeArray(arguments);
                checkFire();
            });
        });
    };

    // unsupported, non-API function
    fluid.event.dispatchListener = function (that, listener, eventName, eventSpec, indirectArgs) {
        return function () {
            fluid.pushActivity("dispatchListener", "firing to listener to event named %eventName of component %that",
                {eventName: eventName, that: that});
            if (typeof(listener) === "string") {
                listener = fluid.event.resolveListener({globalName: listener}); // just resolves globals
            }
            var args = indirectArgs? arguments[0] : fluid.makeArray(arguments);
            var demandspec = fluid.determineDemands(that, eventName); // TODO: This name may contain a namespace
            if (demandspec.args.length === 0 && eventSpec.args) {
                demandspec.args = eventSpec.args;
            }
            var resolved = fluid.embodyDemands(that, demandspec, args, {passArgs: true});
            var togo = listener.apply(null, resolved.args);
            fluid.popActivity();
            return togo;
        };
    };

    // unsupported, non-API function
    fluid.event.resolveSoftNamespace = function (key) {
        if (typeof(key) !== "string") {
            return null;
        } else {
            var lastpos = Math.max(key.lastIndexOf("."), key.lastIndexOf("}"));
            return key.substring(lastpos + 1);
        }
    };

    // unsupported, non-API function
    fluid.event.resolveListenerRecord = function (lisrec, that, eventName, namespace) {
        var badRec = function (record, extra) {
            fluid.fail("Error in listener record - could not resolve reference ", record, " to a listener or firer. "
                    + "Did you miss out \"events.\" when referring to an event firer?" + extra);
        };
        fluid.pushActivity("resolveListenerRecord", "resolving listener record for event named %eventName for component %that",
            {eventName: eventName, that: that});
        var records = fluid.makeArray(lisrec);
        var transRecs = fluid.transform(records, function (record) {
            var expanded = fluid.isPrimitive(record) || record.expander ? {listener: record} : record;
            var methodist = fluid.recordToApplicable(record, that);
            if (methodist) {
                expanded.listener = methodist;
            }
            else {
                expanded.listener = expanded.listener || expanded.func || expanded.funcName;
            }
            if (!expanded.listener) {
                badRec(record, " Listener record must contain a member named \"listener\", \"func\", \"funcName\" or \"method\"");
            }
            var softNamespace = record.method ?
                fluid.event.resolveSoftNamespace(record["this"]) + "." + record.method :
                fluid.event.resolveSoftNamespace(expanded.listener);
            if (!expanded.namespace && !namespace && softNamespace) {
                expanded.softNamespace = true;
                expanded.namespace = (record.componentSource ? record.componentSource : that.typeName) + "." + softNamespace;
            }
            var listener = expanded.listener = fluid.expandOptions(expanded.listener, that);
            if (!listener) {
                badRec(record, "");
            }
            var firer;
            if (listener.typeName === "fluid.event.firer") {
                listener = listener.fire;
                firer = true;
            }
            expanded.listener = expanded.args || firer ? fluid.event.dispatchListener(that, listener, eventName, expanded) : listener;
            return expanded;
        });
        var togo = {
            records: transRecs,
            adderWrapper: fluid.event.makeTrackedListenerAdder(that)
        };
        fluid.popActivity();
        return togo;
    };

    // unsupported, non-API function
    fluid.event.expandOneEvent = function (that, event) {
        var origin;
        if (typeof(event) === "string" && event.charAt(0) !== "{") {
            // Shorthand for resolving onto our own events, but with GINGER WORLD!
            origin = fluid.getForComponent(that, ["events", event]);
        }
        else {
            origin = fluid.expandOptions(event, that);
        }
        if (!origin || origin.typeName !== "fluid.event.firer") {
            fluid.fail("Error in event specification - could not resolve base event reference ", event, " to an event firer: got ", origin);
        }
        return origin;
    };

    // unsupported, non-API function
    fluid.event.expandEvents = function (that, event) {
        return typeof(event) === "string" ?
            fluid.event.expandOneEvent(that, event) :
            fluid.transform(event, function (oneEvent) {
                return fluid.event.expandOneEvent(that, oneEvent);
            });
    };

    // unsupported, non-API function
    fluid.event.resolveEvent = function (that, eventName, eventSpec) {
        fluid.pushActivity("resolveEvent", "resolving event with name %eventName attached to component %that",
            {eventName: eventName, that: that});
        var adder = fluid.event.makeTrackedListenerAdder(that);
        if (typeof(eventSpec) === "string") {
            eventSpec = {event: eventSpec};
        }
        var event = eventSpec.event || eventSpec.events;
        if (!event) {
            fluid.fail("Event specification for event with name " + eventName + " does not include a base event specification: ", eventSpec);
        }

        var origin = fluid.event.expandEvents(that, event);

        var isMultiple = origin.typeName !== "fluid.event.firer";
        var isComposite = eventSpec.args || isMultiple;
        // If "event" is not composite, we want to share the listener list and FIRE method with the original
        // If "event" is composite, we need to create a new firer. "composite" includes case where any boiling
        // occurred - this was implemented wrongly in 1.4.
        var firer;
        if (isComposite) {
            firer = fluid.event.getEventFirer(null, null, " [composite] " + fluid.event.nameEvent(that, eventName));
            var dispatcher = fluid.event.dispatchListener(that, firer.fire, eventName, eventSpec, isMultiple);
            if (isMultiple) {
                fluid.event.listenerEngine(origin, dispatcher, adder);
            }
            else {
                adder(origin).addListener(dispatcher);
            }
        }
        else {
            firer = {typeName: "fluid.event.firer"}; // jslint:ok - already defined
            firer.fire = function () {
                var outerArgs = fluid.makeArray(arguments);
                fluid.pushActivity("fireSynthetic", "firing synthetic event %eventName ", {eventName: eventName});
                var togo = origin.fire.apply(null, outerArgs);
                fluid.popActivity();
                return togo;
            };
            firer.addListener = function (listener, namespace, predicate, priority, softNamespace) {
                var dispatcher = fluid.event.dispatchListener(that, listener, eventName, eventSpec);
                adder(origin).addListener(dispatcher, namespace, predicate, priority, softNamespace);
            };
            firer.removeListener = function (listener) {
                origin.removeListener(listener);
            };
        }
        fluid.popActivity();
        return firer;
    };

    /** BEGIN unofficial IoC material **/
    // Although the following three functions are unsupported and not part of the IoC
    // implementation proper, they are still used in the renderer
    // expander as well as in some old-style tests and various places in CSpace.

    // unsupported, non-API function
    fluid.withEnvironment = function (envAdd, func, root) {
        root = root || fluid.globalThreadLocal();
        return fluid.tryCatch(function() {
            for (var key in envAdd) {
                root[key] = envAdd[key];
            }
            $.extend(root, envAdd);
            return func();
        }, null, function() {
            for (var key in envAdd) { // jslint:ok duplicate "value"
                delete root[key]; // TODO: users may want a recursive "scoping" model
            }
        });
    };

    // unsupported, NON-API function
    fluid.fetchContextReference = function (parsed, directModel, env, elResolver, externalFetcher) {
        // The "elResolver" is a hack to make certain common idioms in protoTrees work correctly, where a contextualised EL
        // path actually resolves onto a further EL reference rather than directly onto a value target
        if (elResolver) {
            parsed = elResolver(parsed, env);
        }
        var base = parsed.context? env[parsed.context] : directModel;
        if (!base) {
            var resolveExternal = externalFetcher && externalFetcher(parsed);
            return resolveExternal || base;
        }
        return parsed.noDereference? parsed.path : fluid.get(base, parsed.path);
    };

    // unsupported, non-API function
    fluid.makeEnvironmentFetcher = function (directModel, elResolver, envGetter, externalFetcher) {
        envGetter = envGetter || fluid.globalThreadLocal;
        return function(parsed) {
            var env = envGetter();
            return fluid.fetchContextReference(parsed, directModel, env, elResolver, externalFetcher);
        };
    };

    /** END of unofficial IoC material **/

    // unsupported, non-API function
    fluid.extractEL = function (string, options) {
        if (options.ELstyle === "ALL") {
            return string;
        }
        else if (options.ELstyle.length === 1) {
            if (string.charAt(0) === options.ELstyle) {
                return string.substring(1);
            }
        }
        else if (options.ELstyle === "${}") {
            var i1 = string.indexOf("${");
            var i2 = string.lastIndexOf("}");
            if (i1 === 0 && i2 !== -1) {
                return string.substring(2, i2);
            }
        }
    };

    // unsupported, non-API function
    fluid.extractELWithContext = function (string, options) {
        var EL = fluid.extractEL(string, options);
        if (EL && EL.charAt(0) === "{" && EL.indexOf("}") > 0) {
            return fluid.parseContextReference(EL);
        }
        return EL? {path: EL} : EL;
    };

    fluid.parseContextReference = function (reference, index, delimiter) {
        index = index || 0;
        var endcpos = reference.indexOf("}", index + 1);
        if (endcpos === -1) {
            fluid.fail("Cannot parse context reference \"" + reference + "\": Malformed context reference without }");
        }
        var context = reference.substring(index + 1, endcpos);
        var endpos = delimiter? reference.indexOf(delimiter, endcpos + 1) : reference.length;
        var path = reference.substring(endcpos + 1, endpos);
        if (path.charAt(0) === ".") {
            path = path.substring(1);
        }
        return {context: context, path: path, endpos: endpos};
    };

    fluid.renderContextReference = function (parsed) {
        return "{" + parsed.context + "}." + parsed.path;
    };

    // unsupported, non-API function
    fluid.resolveContextValue = function (string, options) {
        function fetch(parsed) {
            fluid.pushActivity("resolveContextValue", "resolving context value %string", {string: string});
            var togo = options.fetcher(parsed);
            fluid.pushActivity("resolvedContextValue", "resolved value %string to value %value", {string: string, value: togo});
            fluid.popActivity(2);
            return togo;
        }
        if (options.bareContextRefs && string.charAt(0) === "{" && string.indexOf("}") > 0) {
            var parsed = fluid.parseContextReference(string);
            return fetch(parsed);
        }
        else if (options.ELstyle && options.ELstyle !== "${}") {
            var parsed = fluid.extractELWithContext(string, options); // jslint:ok, redefinition
            if (parsed) {
                return fetch(parsed);
            }
        }
        while (typeof(string) === "string") {
            var i1 = string.indexOf("${");
            var i2 = string.indexOf("}", i1 + 2);
            if (i1 !== -1 && i2 !== -1) {
                var parsed; // jslint:ok
                if (string.charAt(i1 + 2) === "{") {
                    parsed = fluid.parseContextReference(string, i1 + 2, "}");
                    i2 = parsed.endpos;
                }
                else {
                    parsed = {path: string.substring(i1 + 2, i2)};
                }
                var subs = fetch(parsed);
                var all = (i1 === 0 && i2 === string.length - 1);
                // TODO: test case for all undefined substitution
                if (subs === undefined || subs === null) {
                    return subs;
                }
                string = all? subs : string.substring(0, i1) + subs + string.substring(i2 + 1);
            }
            else {
                break;
            }
        }
        return string;
    };

    // unsupported, NON-API function
    fluid.expandExpander = function (target, source, options) {
        var expander = fluid.getGlobalValue(source.expander.type || "fluid.deferredInvokeCall");
        if (expander) {
            return expander.call(null, target, source, options);
        }
    };

    // This function appears somewhat reusable, but not entirely - it probably needs to be packaged
    // along with the particular "strategy". Very similar to the old "filter"... the "outer driver" needs
    // to execute it to get the first recursion going at top level. This was one of the most odd results
    // of the reorganisation, since the "old work" seemed much more naturally expressed in terms of values
    // and what happened to them. The "new work" is expressed in terms of paths and how to move amongst them.
    fluid.fetchExpandChildren = function (target, i, segs, source, mergePolicy, miniWorld, options) {
        if (source.expander /* && source.expander.type */) { // possible expander at top level
            var expanded = fluid.expandExpander(target, source, options);
            if (fluid.isPrimitive(expanded) || fluid.isDOMish(expanded) || (fluid.isArrayable(expanded) ^ fluid.isArrayable(target))) {
                return expanded;
            }
            else { // make an attempt to preserve the root reference if possible
                $.extend(true, target, expanded);
            }
        }
        // NOTE! This expects that RHS is concrete! For material input to "expansion" this happens to be the case, but is not
        // true for other algorithms. Inconsistently, this algorithm uses "sourceStrategy" below. In fact, this "fetchChildren"
        // operation looks like it is a fundamental primitive of the system. We do call "deliverer" early which enables correct
        // reference to parent nodes up the tree - however, anyone processing a tree IN THE CHAIN requires that it is produced
        // concretely at the point STRATEGY returns. Which in fact it is...............
        fluid.each(source, function (newSource, key) {
            if (newSource === undefined) {
                target[key] = undefined; // avoid ever dispatching to ourselves with undefined source
            }
            else if (key !== "expander") {
                segs[i] = key;
                options.strategy(target, key, i + 1, segs, source, mergePolicy, miniWorld);
            }
        });
        return target;
    };

    // TODO: This method is unnecessary and will quadratic inefficiency if RHS block is not concrete.
    // The driver should detect "homogeneous uni-strategy trundling" and agree to preserve the extra
    // "cursor arguments" which should be advertised somehow (at least their number)
    function regenerateCursor (source, segs, limit, sourceStrategy) {
        for (var i = 0; i < limit; ++ i) {
            source = sourceStrategy(source, segs[i], i, segs);
        }
        return source;
    }

    // unsupported, NON-API function
    fluid.isUnexpandable = function (source) {
        return fluid.isPrimitive(source) || source.nodeType !== undefined || source.jquery;
    };

    // unsupported, NON-API function    
    fluid.expandSource = function (options, target, i, segs, deliverer, source, policy, miniWorld, recurse) {
        var expanded, isTrunk, isLate;
        var thisPolicy = fluid.derefMergePolicy(policy);
        if (typeof (source) === "string" && !thisPolicy.noexpand) {
            if (!options.defaultEL || source.charAt(0) === "{") { // hard-code this for performance
                fluid.pushActivity("expandContextValue", "expanding context value %source held at path %path", {source: source, path: fluid.path.apply(null, segs.slice(0, i))});
                expanded = fluid.resolveContextValue(source, options);
                fluid.popActivity(1);
            } else {
                expanded = source;
            }
        }
        else if (thisPolicy.noexpand || fluid.isUnexpandable(source)) {
            expanded = source;
        }
        else if (source.expander) {
            expanded = fluid.expandExpander(deliverer, source, options);
        }
        else {
            if (thisPolicy.preserve) {
                expanded = source;
                isLate = true;
            }
            else {
                expanded = fluid.freshContainer(source);
            }
            isTrunk = true;
        }
        if (!isLate && expanded !== fluid.NO_VALUE) {
            deliverer(expanded);
        }
        if (isTrunk) {
            recurse(expanded, source, i, segs, policy, miniWorld || isLate);
        }
        if (isLate && expanded !== fluid.NO_VALUE) {
            deliverer(expanded);
        }
        return expanded;
    };

    // unsupported, NON-API function
    fluid.makeExpandStrategy = function (options) {
        var recurse = function (target, source, i, segs, policy, miniWorld) {
            return fluid.fetchExpandChildren(target, i || 0, segs || [], source, policy, miniWorld, options);
        };
        var strategy = function (target, name, i, segs, source, policy, miniWorld) {
            if (i > fluid.strategyRecursionBailout) {
                fluid.fail("Overflow/circularity in options expansion, current path is ", segs, " at depth " , i, " - please ensure options are not circularly connected, or protect from expansion using the \"noexpand\" policy or expander");
            }
            if (!target) {
                return;
            }
            if (!miniWorld && target.hasOwnProperty(name)) { // bail out if our work has already been done
                return target[name];
            }
            if (source === undefined) { // recover our state in case this is an external entry point
                source = regenerateCursor(options.source, segs, i - 1, options.sourceStrategy);
                policy = regenerateCursor(options.mergePolicy, segs, i - 1, fluid.concreteTrundler);
            }
            var thisSource = options.sourceStrategy(source, name, i, segs);
            var thisPolicy = fluid.concreteTrundler(policy, name);
            function deliverer(value) {
                target[name] = value;
            }
            return fluid.expandSource(options, target, i, segs, deliverer, thisSource, thisPolicy, miniWorld, recurse);
        };
        options.recurse = recurse;
        options.strategy = strategy;
        return strategy;
    };

    fluid.defaults("fluid.makeExpandOptions", {
        ELstyle:          "${}",
        bareContextRefs:  true,
        target:           fluid.inCreationMarker
    });

    // unsupported, NON-API function
    fluid.makeExpandOptions = function (source, options) {
        options = $.extend({}, fluid.rawDefaults("fluid.makeExpandOptions"), options);
        options.defaultEL = options.ELStyle === "${}" && options.bareContextRefs; // optimisation to help expander
        options.expandSource = function (source) {
            return fluid.expandSource(options, null, 0, [], fluid.identity, source, options.mergePolicy, false);
        };
        if (!fluid.isUnexpandable(source)) {
            options.source = source;
            options.target = fluid.freshContainer(source);
            options.sourceStrategy = options.sourceStrategy || fluid.concreteTrundler;
            fluid.makeExpandStrategy(options);
            options.initter = function () {
                options.target = fluid.fetchExpandChildren(options.target, 0, [], options.source, options.mergePolicy, false, options);
            };
        }
        else { // these init immediately since we must deliver a valid root target
            options.strategy = fluid.concreteTrundler;
            options.initter = fluid.identity;
            if (typeof(source) === "string") {
                options.target = options.expandSource(source);
            }
            else {
                options.target = source;
            }
        }
        return options;
    };

    fluid.expand = function (source, options) {
        var expandOptions = fluid.makeExpandOptions(source, options);
        expandOptions.initter();
        return expandOptions.target;
    };

    fluid.registerNamespace("fluid.expander");

    /** "light" expanders, starting with support functions for the so-called "deferredCall" expanders,
         which make an arbitrary function call (after expanding arguments) and are then replaced in
         the configuration with the call results. These will probably be abolished and replaced with
         equivalent model transformation machinery **/

    fluid.expander.deferredCall = function (deliverer, source, options) {
        var expander = source.expander;
        var args = (!expander.args || fluid.isArrayable(expander.args))? expander.args : fluid.makeArray(expander.args);
        args = options.recurse([], args);
        return fluid.invokeGlobalFunction(expander.func, args);
    };

    fluid.deferredCall = fluid.expander.deferredCall; // put in top namespace for convenience

    // This one is now positioned as the "universal expander" - default if no type supplied
    fluid.deferredInvokeCall = function (deliverer, source, options) {
        var expander = source.expander;
        var args = fluid.makeArray(expander.args);
        args = options.recurse([], args); // TODO: risk of double expansion here. embodyDemands will sometimes expand, sometimes not...
        var funcEntry = expander.func || expander.funcName;
        var func = options.expandSource(funcEntry) || fluid.recordToApplicable(expander, options.contextThat);
        if (!func) {
            fluid.fail("Error in expander record - " + funcEntry + " could not be resolved to a function for component ", options.contextThat);
        }
        return func.apply ? func.apply(null, args) : fluid.invoke(func, args, options.contextThat);
    };

    // The "noexpand" expander which simply unwraps one level of expansion and ceases.
    fluid.expander.noexpand = function (deliverer, source) {
        return source.expander.value ? source.expander.value : source.expander.tree;
    };

    fluid.noexpand = fluid.expander.noexpand; // TODO: check naming and namespacing


})(jQuery, fluid_1_5);