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More work on removing updateFromJS
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@sagacity
sagacity committed Aug 20, 2011
1 parent bff3c18 commit 5199587
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Showing 4 changed files with 271 additions and 231 deletions.
164 changes: 96 additions & 68 deletions build/output/knockout.mapping-latest.debug.js
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Original file line number Diff line number Diff line change
@@ -1,7 +1,7 @@
// Knockout Mapping plugin v2.0beta
// (c) 2011 Steven Sanderson, Roy Jacobs - http://knockoutjs.com/
// License: Ms-Pl (http://www.opensource.org/licenses/ms-pl.html)

// Knockout Mapping plugin v2.0beta
// (c) 2011 Steven Sanderson, Roy Jacobs - http://knockoutjs.com/
// License: Ms-Pl (http://www.opensource.org/licenses/ms-pl.html)

// Google Closure Compiler helpers (used only to make the minified file smaller)
ko.exportSymbol = function (publicPath, object) {
var tokens = publicPath.split(".");
Expand Down Expand Up @@ -52,14 +52,26 @@ ko.exportProperty = function (owner, publicName, object) {
return unwrapped && unwrapped[mappingProperty];
}

ko.mapping.fromJS = function (jsObject, inputOptions, target) {
ko.mapping.fromJS = function (jsObject/*, inputOptions, target*/) {
if (arguments.length == 0) throw new Error("When calling ko.fromJS, pass the object you want to convert.");

var options;
var target;

if (arguments.length == 2) {
if (arguments[1][mappingProperty]) {
target = arguments[1];
} else {
options = arguments[1];
}
}
if (arguments.length == 3) {
options = arguments[1];
target = arguments[2];
}

if (target) {
options = merge(inputOptions, target[mappingProperty]);
} else {
options = inputOptions;
options = merge(options, target[mappingProperty]);
}
options = fillOptions(options);

Expand All @@ -74,9 +86,10 @@ ko.exportProperty = function (owner, publicName, object) {
return result;
};

ko.mapping.fromJSON = function (jsonString, options, target) {
ko.mapping.fromJSON = function (jsonString/*, options, target*/) {
var parsed = ko.utils.parseJson(jsonString);
return ko.mapping.fromJS(parsed, options, target);
arguments[0] = parsed;
return ko.mapping.fromJS.apply(this, arguments);
};

ko.mapping.updateFromJS = function (viewModel) {
Expand Down Expand Up @@ -167,6 +180,8 @@ ko.exportProperty = function (owner, publicName, object) {
return a.concat(b);
}

// When using a 'create' callback, we proxy the dependent observable so that it doesn't immediately evaluate on creation.
// The reason is that the dependent observables in the user-specified callback may contain references to properties that have not been mapped yet.
function withProxyDependentObservable(callback) {
var localDO = ko.dependentObservable;
ko.dependentObservable = function() {
Expand All @@ -191,13 +206,40 @@ ko.exportProperty = function (owner, publicName, object) {
var previousMapping = ko.utils.unwrapObservable(mappedRootObject)[mappingProperty];
options = merge(previousMapping, options);
}

var hasCreateCallback = function () {
return options[parentName] && options[parentName].create instanceof Function;
}

var hasUpdateCallback = function () {
return options[parentName] && options[parentName].update instanceof Function;
var callbackParams = {
data: rootObject,
parent: parent
};

var hasCreateCallback = function() {
return options[parentName] && options[parentName].create instanceof Function;
};

var createCallback = function (data) {
return withProxyDependentObservable(function() {
return options[parentName].create({
data: data || callbackParams.data,
parent: callbackParams.parent
});
});
};

var hasUpdateCallback = function() {
return options[parentName] && options[parentName].update instanceof Function;
};

var updateCallback = function (obj) {
var params = {
data: callbackParams.data,
parent: callbackParams.parent
};

if (ko.isWriteableObservable(obj)) {
params.observable = obj;
}

return options[parentName].update(ko.utils.unwrapObservable(obj), params);
}

visitedObjects = visitedObjects || new objectLookup();
Expand All @@ -215,50 +257,41 @@ ko.exportProperty = function (owner, publicName, object) {
default:
if (ko.isWriteableObservable(mappedRootObject)) {
if (hasUpdateCallback()) {
mappedRootObject(options[parentName].update(ko.utils.unwrapObservable(mappedRootObject), {
data: rootObject,
parent: parent
}));
mappedRootObject(updateCallback(mappedRootObject));
} else {
mappedRootObject(ko.utils.unwrapObservable(rootObject));
}
} else {
if (hasCreateCallback()) {
mappedRootObject = withProxyDependentObservable(function() {
return options[parentName].create({
data: rootObject,
parent: parent
});
});
mappedRootObject = createCallback();
} else {
mappedRootObject = ko.observable(ko.utils.unwrapObservable(rootObject));
}

if (hasUpdateCallback()) {
mappedRootObject(updateCallback(mappedRootObject));
}
}
break;
}

} else {
if (!mappedRootObject) {
if (hasCreateCallback()) {
// When using a 'create' callback, we proxy the dependent observable so that it doesn't immediately evaluate on creation.
// The reason is that the dependent observables in the user-specified callback may contain references to properties that have not been mapped yet.
var result = withProxyDependentObservable(function() {
return options[parentName].create({
data: rootObject,
parent: parent
});
});
var result = createCallback();

if (hasUpdateCallback()) {
result = updateCallback(result);
}

return result;
} else {
mappedRootObject = {};
}
}

if (hasUpdateCallback()) {
return options[parentName].update(ko.utils.unwrapObservable(mappedRootObject), {
data: rootObject,
parent: parent
});
updateCallback(mappedRootObject);
}
mappedRootObject = ko.utils.unwrapObservable(mappedRootObject);

Expand All @@ -277,27 +310,17 @@ ko.exportProperty = function (owner, publicName, object) {
return;
}

var mappedProperty;

// In case we are adding an already mapped property, fill it with the previously mapped property value to prevent recursion.
// If this is a property that was generated by fromJS, we should use the options specified there
var prevMappedProperty = visitedObjects.get(rootObject[indexer]);
if (prevMappedProperty) {
// In case we are adding an already mapped property, fill it with the previously mapped property value to prevent recursion.
if (ko.isWriteableObservable(mappedRootObject[indexer])) {
mappedRootObject[indexer](prevMappedProperty);
} else {
mappedRootObject[indexer] = prevMappedProperty;
}
} else {
// If this is a property that was generated by fromJS, we should use the options specified there
if (ko.isWriteableObservable(mappedRootObject[indexer])) {
var val = updateViewModel(mappedRootObject[indexer](), rootObject[indexer], options, visitedObjects, indexer, mappedRootObject, fullPropertyName);
mappedRootObject[indexer](ko.utils.unwrapObservable(val));
} else {
var val = updateViewModel(mappedRootObject[indexer], rootObject[indexer], options, visitedObjects, indexer, mappedRootObject, fullPropertyName);
mappedRootObject[indexer] = val;
}
}

var value = prevMappedProperty || updateViewModel(ko.utils.unwrapObservable(mappedRootObject[indexer]), rootObject[indexer], options, visitedObjects, indexer, mappedRootObject, fullPropertyName);

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@jpc

jpc Sep 9, 2011

Contributor

The unwrap here causes the updateViewModel to recreate the array as an empty observableArray, effectively prohibiting any incremental array updates. This causes problems even when no changes were made to said array at all.

if (ko.isWriteableObservable(mappedRootObject[indexer])) {
mappedRootObject[indexer](ko.utils.unwrapObservable(value));
} else {
mappedRootObject[indexer] = value;
}

options.mappedProperties[fullPropertyName] = true;
});
}
Expand Down Expand Up @@ -331,8 +354,8 @@ ko.exportProperty = function (owner, publicName, object) {

if (hasUpdateCallback()) {
updateCallBack = function(item) {
return options[parentName].update(ko.uitls.unwrapObservable(item), {
data: value,
return options[parentName].update(ko.utils.unwrapObservable(item), {
data: ko.utils.unwrapObservable(item),
parent: parent
});
}
Expand Down Expand Up @@ -376,15 +399,20 @@ ko.exportProperty = function (owner, publicName, object) {
return ko.utils.arrayIndexOf(keys, key);
}

mappedRootObject.mappedCreate = function(value){
mappedRootObject.mappedCreate = function(value){
if (mappedRootObject.mappedIndexOf(value) !== -1) {
throw new Error("There already is an object with the key that you specified.");
}

var item = createCallBack(value);
if (ko.isWriteableObservable(item)) {
item(updateCallBack(item));
}

var item = createCallback(value);
if (hasUpdateCallback()) {
var newValue = updateCallback(item);
if (ko.isWriteableObservable(item)) {
item(newValue);
} else {
item = newValue;
}
}
mappedRootObject.push(item);
return item;
}
Expand Down Expand Up @@ -446,7 +474,7 @@ ko.exportProperty = function (owner, publicName, object) {
function ignorableIndexOf(array, item, ignoreIndices) {
for (var i = 0, j = array.length; i < j; i++) {
if (ignoreIndices[i] === true) continue;
if (array[i] == item) return i;
if (array[i] === item) return i;
}
return null;
}
Expand Down Expand Up @@ -492,7 +520,7 @@ ko.exportProperty = function (owner, publicName, object) {

function canHaveProperties(object) {
var type = getType(object);
return (type == "object") && (object !== null) && (type !== "undefined");
return (type === "object") && (object !== null) && (type !== "undefined");
}

// Based on the parentName, this creates a fully classified name of a property
Expand Down

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