previous-versions.js

/*jshint
    expr:   true
*/
// Module core/biblio/previous-versions
// This module provides an object that finds "previousVersions"
// properties in bibliographies and expands them so they can
// be used in specifications.

define([], function() {
    'use strict';
    var prevVersionExpander = {};

    function expandPrevVersions(bib, msg) {
        var props = Object.getOwnPropertyNames(bib);

        function hasPrevVersion(key) {
            var entry = bib[key],
                prop = 'previousVersions',
                isValid = !! entry[prop] && entry[prop] instanceof Array;
            if (isValid) {
                processPrevVersions(key, entry);
            }
        }

        function processPrevVersions(key, parentEntry) {
            parentEntry.previousVersions.forEach(function(prevObj, index) {
                var warning = '',
                    newKey = key + '-' + prevObj['key'];

                if ((typeof prevObj) !== 'object') {
                    warning = 'Expected Object, but got ' + (typeof prevObj) + '?';
                    warning += ' Please fix: ' + key + ' at index ' + index + '.';
                    msg('error', warning);
                    return;
                }

                if (!prevObj.hasOwnProperty('key')) {
                    warning = 'Previous versions require a key property. ';
                    warning += 'Please fix: ' + key;
                    msg('error', warning);
                    return;
                }

                if (bib[newKey]) {
                    warning = 'Previous version (' + newKey + ') already in biblio. ';
                    warning += 'Please fix previousVersion key: ' + prevObj.key;
                    msg('error', warning);
                    return;
                }
                addPrevVersion(newKey, parentEntry, prevObj);
            });
        }

        function addPrevVersion(newKey, parentEntry, prevObj) {
            var parentProps = Object.getOwnPropertyNames(parentEntry),
                newProps = Object.getOwnPropertyNames(prevObj),
                allProps = parentProps.concat(newProps).sort().filter(clean),
                newEntry = bib[newKey] = {};

            //Don't add props to aliased entries, they are handeled by another plugin
            if (prevObj.hasOwnProperty('aliasOf')) {
                newEntry.aliasOf = prevObj.aliasOf;
                return;
            }
            allProps.forEach(function(prop) {
                var value = prevObj[prop] || parentEntry[prop];
                this[prop] = value;
            }, newEntry);

            //remove duplicates, "previousVersions", and "key" prop

            function clean(elem, pos, self) {
                if (elem === 'previousVersions' || elem === 'key') {
                    return false;
                }
                return self.lastIndexOf(elem) === pos;
            }
        }
        props.forEach(hasPrevVersion);
    }

    prevVersionExpander.run = function(conf, doc, cb, msg) {
        var biblio,
            props = {
            get: function() {
                return biblio;
            },
            set: function(obj) {
                if ((typeof obj) === 'object') {
                    biblio = obj;
                    expandPrevVersions(obj, msg);
                }
            }
        };
        msg.pub('start', 'core/biblio/previous-versions');
        if (conf.localBiblio) {
            expandPrevVersions(conf.localBiblio, msg);
        }
        if (berjon.biblio) {
            expandPrevVersions(berjon.biblio, msg);
        } else {
            //we take over getting and setting of
            //berjon.biblio, so to dynamically
            //expand the biblio when loaded.
            Object.defineProperty(berjon, 'biblio', props);
        }
        msg.pub('end', 'core/fix-headers');
        cb();
    };
    return prevVersionExpander;
});