Moved Backbone models/views out to separate files for pdf textbooks project

cms/static/js/models/textbooks.js

+CMS.Models.Textbook = Backbone.AssociatedModel.extend({
+    defaults: function() {
+        return {
+            name: "",
+            chapters: new CMS.Collections.ChapterSet([{}]),
+            showChapters: false
+        };
+    },
+    relations: [{
+        type: Backbone.Many,
+        key: "chapters",
+        relatedModel: "CMS.Models.Chapter",
+        collectionType: "CMS.Collections.ChapterSet"
+    }],
+    isEmpty: function() {
+        return !this.get('name') && this.get('chapters').isEmpty();
+    },
+    parse: function(response) {
+        if("tab_title" in response && !("name" in response)) {
+            response.name = response.tab_title;
+            delete response.tab_title;
+        }
+        if("url" in response && !("chapters" in response)) {
+            response.chapters = {"url": response.url};
+            delete response.url;
+        }
+        _.each(response.chapters, function(chapter, i) {
+            chapter.order = chapter.order || i+1;
+        });
+        return response;
+    },
+    toJSON: function() {
+        return {
+            tab_title: this.get('name'),
+            chapters: this.get('chapters').toJSON()
+        };
+    }
+});
+CMS.Collections.TextbookSet = Backbone.Collection.extend({
+    model: CMS.Models.Textbook,
+    url: function() { return window.TEXTBOOK_URL; },
+    initialize: function() {
+        this.listenTo(this, "editOne", this.editOne);
+    },
+    editOne: function(textbook) {
+        this.editing = textbook;
+    },
+    save: function(options) {
+        return this.sync('update', this, options);
+    }
+});
+CMS.Models.Chapter = Backbone.AssociatedModel.extend({
+    defaults: function() {
+        return {
+            name: "",
+            asset_path: "",
+            order: this.collection ? this.collection.nextOrder() : 1
+        };
+    },
+    isEmpty: function() {
+        return !this.get('name') && !this.get('asset_path');
+    },
+    parse: function(response) {
+        if("title" in response && !("name" in response)) {
+            response.name = response.title;
+            delete response.title;
+        }
+        if("url" in response && !("asset_path" in response)) {
+            response.asset_path = response.url;
+            delete response.url;
+        }
+        return response;
+    },
+    toJSON: function() {
+        return {
+            title: this.get('name'),
+            url: this.get('asset_path')
+        };
+    }
+});
+CMS.Collections.ChapterSet = Backbone.Collection.extend({
+    model: CMS.Models.Chapter,
+    comparator: "order",
+    nextOrder: function() {
+        if(!this.length) return 1;
+        return this.last().get('order') + 1;
+    },
+    isEmpty: function() {
+        return this.length === 0 || this.every(function(m) { return m.isEmpty(); });
+    }
+});
+CMS.Models.FileUpload = Backbone.Model.extend({
+    defaults: {
+        "title": "",
+        "message": "",
+        "selectFile": null,
+        "uploading": false,
+        "uploadedBytes": 0,
+        "totalBytes": 0
+    }
+});