Backbone Collection.fetch gives me Uncaught TypeError: object is not a function

Asked By: Anonymous

I’m working on a Backbone app with RequireJS and lo-dash libraries, everything working fine but I’m having problems with setting json data to my Collection objects.

The RequireJS configuration:

require.config({
baseUrl: 'js',

paths: {
    // Aliases for libraries, so that we can change versions from here
    jquery: 'libs/jquery-1.10.min',
    // Lo-Dash is a better drop-in replacement for Underscore: http://lodash.com/
    lodash: 'libs/lodash-1.2.0.min',
    requireLib: 'libs/require-2.1.6-min',
    almondLib: 'libs/almond-0.2.5',
    backbone: 'libs/backbone-1.0.0.min',
    less:'libs/less-1.4.0.min'
},

shim: {
    'backbone': {
        //These script dependencies should be loaded before loading
        //backbone.js
        deps: ['lodash', 'jquery'],
        //Once loaded, use the global 'Backbone' as the
        //module value.
        exports: 'Backbone'
    }
},

// This is appended to every module loading request, for cache invalidation purposes
urlArgs: "bust=" + (new Date()).getTime()
});

And my page.html

<script type="text/javascript">
    require(["app/views/catalog"], function (Catalog) {
        var app = new Catalog.App();
    });

    //require(['libraries', 'cs!auth-main']);
</script>

This is my Model library

define([
'jquery',
'lodash',
'backbone'
],
function ($, _, Backbone) {

    var CatalogModel = {};

    CatalogModel.App = Backbone.Model.extend({
        defaults: {
            name: "Catalog without name",
            userdata: false,
            documents: false
        },
        initialize:function () {
            console.log("Model - App.initialize");
            this.on("change", function () {
                console.log("Model - App.change");
            });
        },
        url:"json/logged_data.json"
    });

    CatalogModel.User = Backbone.Model.extend({
        defaults: {
            username: "Default username"
        },
        initialize: function () {
            console.log("Model - User.initialize");
            this.on("change", function () {
                console.log("Model - User.change");
            });
        }
    });

    CatalogModel.Document = Backbone.Model.extend({
        defaults: {
            name: "Default catalog name",
            status: {
                url: "#",
                ready: false,
                downloadableProductUrl: "#"
            }
        },
        initialize: function () {
            //console.log("CatalogModel.DocumentBrowse.initialize");
            this.on("change", function () {
                console.log("Model - Document.change");
            });
        }
    });

    CatalogModel.Asset = Backbone.Model.extend({
        defaults: {
            nodeType:"folder",
            name:"Default folder name",
            url:false,
            treeId:"0",
            collection:false
        },
        initialize: function () {
            console.log("Model - Asset.initialize");
            this.on("change", function () {
                console.log("Model - Asset.change");
            });
        }
    });

    return CatalogModel;
}
);

This is my Collection library

define([
'jquery',
'lodash',
'backbone',
'app/models/catalog'
],
function ($, _, Backbone, CatalogModel) {

    var CatalogCollection = {};

    CatalogCollection.DocumentsList = Backbone.Collection.extend({
        initialize: function () {
            console.log("Collection - DocumentsList.initialize");
            this.model = new CatalogModel.Document();
            this.on("add", function () {
                console.log("Collection - DocumentsList.add");
            });
        }
    });

    CatalogCollection.AssetsList = Backbone.Collection.extend({
        initialize: function () {
            console.log("Collection - AssetsList.initialize");
            this.model = new CatalogModel.Asset();
            this.on("add", function () {
                console.log("Collection - AssetsList.change");
            });
        },
        parse: function(response) {
            console.log("Collection - AssetsList.parse");
            //console.log(response);
            return response;
        },
        url:"json/assets_nodes.json"
    });

    return CatalogCollection;
}
);

And this is my Views library

define([
'jquery',
'lodash',
'backbone',
'app/models/catalog',
'app/collections/catalog',
'libs/text!app/templates/account_bar.html',
'libs/text!app/templates/document_browser.html',
'libs/text!app/templates/document_editor.html',
'libs/text!app/templates/document_name.html',
'libs/text!app/templates/assets_nodes.html',
'libs/text!app/templates/assets_children.html'
// ,'libs/text!app/templates/assets_items.html'
],
function ($, _, Backbone, CatalogModel, CatalogCollection, tmplAccountBar, tmplDocumentsBrowser, tmplDocumentEditor, tmplDocumentName, tmplAssetsNodes, tmplAssetsChildren) {

    var Catalog = {};

    Catalog.App = Backbone.View.extend({
        el: $("#catalog"),
        initialize: function() {
            console.log("View - App.inizialize");

            this.tmplDocumentEditor = tmplDocumentEditor;

            // here i'll set subviews for user bar, doc browser, assets list and book editor
            this.UserBarSubView = new Catalog.UserBarView();
            this.DocumentsBrowserSubView = new Catalog.DocumentsBrowserView();
            this.AssetsBrowserSubView = new Catalog.AssetsBrowserView();

            this.UserBarSubView.parent = this;
            this.DocumentsBrowserSubView.parent = this;
            this.AssetsBrowserSubView.parent = this;

            this.model = new CatalogModel.App();
            this.listenTo(this.model, "change", this.updateMainRequest);
            this.model.fetch(null);
        },
        updateMainRequest: function(data){
            var data = this.model.toJSON();

            console.log("View - App.updateMainRequest");
            //console.log(data.documents);

            this.UserBarSubView.model.set(data.userdata);

            var documents = [];
            for (var i = data.documents.length - 1; i >= 0; i--) {
                documents.push(new CatalogModel.Document(data.documents[i]));
            };
            this.DocumentsBrowserSubView.collection.set(documents);
        },
        createDocument: function() {
            console.log("View - App.createDocument");
            var name = this.model.get("name");
            //console.log(name);
            this.renderDocumentEditor(name);
        },
        editDocument: function(index) {
            console.log("View - App.editDocument");
            console.log(index);
        },
        renderDocumentEditor: function(name) {
            console.log("View - App.renderDocumentEditor");
            this.$el.find("#docs-browser").remove();
            this.$el.append(this.tmplDocumentEditor);

            this.AssetsBrowserSubView.renderDocumentName({name:name});
            this.AssetsBrowserSubView.collection.fetch();
            /*
            this.$el.find("#assets").html("assets creato dinamicamente");
            this.$el.find("#document-opened").html("doc opened creato dinamicamente");
            */
        }
    });

    Catalog.UserBarView = Backbone.View.extend({
        initialize: function() {
            console.log("View - UserBar.inizialize");
            this.template = tmplAccountBar;
            this.model = new CatalogModel.User();

            // data updates will be managed from Catalog.App
            this.listenTo(this.model, "change", this.render);
        },
        render: function() {
            console.log("View - UserBar.render");
            var accountBar = _.template(this.template, this.model.toJSON());
            this.parent.$el.append(accountBar);
            return;
        }
    });

    Catalog.DocumentsBrowserView = Backbone.View.extend({
        el: $("#catalog"),
        events: {
            "click #new-document": "createDocument",
            "click .open-document": "editDocument"
        },
        initialize: function () {
            //_.bindAll(this, 'createDocument editDocument');
            console.log("View - BrowseDocuments.initialize");

            // template shoud be in the page wrapped inside this tag:
            // <script id="template-test" type="text/template">...</script>

            this.template = tmplDocumentsBrowser;

            this.collection = new CatalogCollection.DocumentsList();

            console.log(this.collection);

            // data updates will be managed from Catalog.App
            this.listenTo(this.collection, "add", this.render);
        },
        createDocument: function() {
            console.log("View - BrowseDocuments.createDocument")
            this.parent.createDocument();
        },
        editDocument: function() {
            //var model = this.collection.get(1);
            //console.log(model.name);
            this.parent.editDocument(-1);
        },
        render: function() {
            console.log("View - BrowseDocuments.render");
            //console.log(this.collection.toJSON());
            var documentsList = _.template(this.template, {documents:this.collection.toJSON()})
            this.parent.$el.append(documentsList);
            this.delegateEvents();
            return;
        }
    });

    // View for assets to place in the catalog will be managed by something like DocumentEditor
    Catalog.AssetsBrowserView = Backbone.View.extend({
        el: $("#catalog"),
        events: {
            "click .folder-closed > div": "openFolder",
            "click .folder-opened > div": "statusClosedFolder"
        },
        initialize: function() {
            console.log("View - AssetsBrowser.initialize");
            //console.log(data);

            this.collection = new CatalogCollection.AssetsList();

            // set in openFolder to get where to place renderChildren
            this.$currentTarget = null;
            this.parentTreeId = false;

            this.tmplAssetsNodes = tmplAssetsNodes;
            this.tmplAssetsChildren = tmplAssetsChildren;
            this.tmplDocumentName = tmplDocumentName;

            // data updates will be managed from Catalog.App
            this.listenToOnce(this.collection, "add", this.renderNodes);
            this.listenTo(this.collection, "add", this.appendList);
        },
        openFolder: function(e) {
            this.$currentTarget = $(e.currentTarget).parent();

            //console.log("= = = = = = = = = = = = = = = = = = = = = = = = = = = = = = ");
            //console.log($(e.currentTarget).html());
            if (this.$currentTarget.find(" > ul").length === 0) {
                console.log("View - AssetsBrowser.openFolder currentTarget DOESN'T have children");
                //console.log(this.$currentTarget.html());
                this.parentTreeId = this.$currentTarget.data("id");

                console.log(this.collection);

                var item = this.collection.where({treeId: this.parentTreeId});
                this.collection.url = item.url;
                this.collection.fetch({success: function(){
                    console.log("got the data"); // => 2 (collection have been populated)
                }});
                this.statusLoadingFolder();
            } else {
                console.log("View - AssetsBrowser.openFolder currentTarget ALLREADY have children");
                //console.log(this.$currentTarget.html());
                this.statusOpenedFolder();
            }
        },
        appendList: function (data) {
            //this.fullCollection = this.fullCollection.push(data);
            console.log("View - AssetsBrowser.appendList");
            //console.log("data.length: " + data[0])

            //var list = $.parseJSON();
            //this.fullItemList = this.fullItemList.concat(this.collection.attributes);

        },
        statusLoadingFolder: function () {
            console.log("View - AssetsBrowser.statusLoadingFolder");
            // change it with a loader
            this.$currentTarget.removeClass("folder-closed").addClass("folder-opened");
            this.$currentTarget.find(".assets-sprite").removeClass("sprite-folder-closed").addClass("sprite-folder-opened");
        },
        statusOpenedFolder: function () {
            // change the css selectors from closed tab to opened tab
            console.log("View - AssetsBrowser.statusOpenedFolder");
            this.$currentTarget.removeClass("folder-closed").addClass("folder-opened");
            this.$currentTarget.find(".assets-sprite").removeClass("sprite-folder-closed").addClass("sprite-folder-opened");
        },
        statusClosedFolder: function (e) {
            var $target = $(e.currentTarget).parent();
            console.log("View - AssetsBrowser.statusClosedFolder");
            //this.$currentTarget.find("ul").remove();
            //console.log(this.$currentTarget);
            $target.removeClass("folder-opened").addClass("folder-closed");
            $target.find(".assets-sprite").removeClass("sprite-folder-opened").addClass("sprite-folder-closed");
        },
        renderDocumentName: function(data) {
            var documentName = _.template(this.tmplDocumentName, data);
            if (this.parent.$el.find("#catalog-name").length === 0) {
                this.parent.$el.find("#assets").prepend(documentName);
            } else {
                this.parent.$el.find("#catalog-name").html(documentName);
            }
        },
        renderNodes: function(data) {
            console.log("View - AssetsBrowser.renderNodes");
            //console.log(this.collection.attributes);
            //this.appendList(this.collection.attributes);
            this.listenTo(this.collection, "add", this.renderChildren);
            //console.log("Catalog.AssetsBrowserView.renderNodes");

            var assetsNodes = _.template(this.tmplAssetsNodes, {nodes:this.collection.toJSON()});
            if (this.parent.$el.find("#assets-browser").length === 0) {
                this.parent.$el.find("#assets").append(assetsNodes);
            } else {
                this.parent.$el.find("#assets-browser").html(assetsNodes);
            }
            this.delegateEvents();
            return;
        },
        renderChildren: function() {
            this.statusOpenedFolder();

            var parentTreeId = this.parentTreeId;

            _.each(this.collection.toJSON(), function (model) {
                model.treeId = parentTreeId;
                console.log(model);
            });

            //this.appendList(this.collection.attributes);
            console.log("View - AssetsBrowser.renderChildren");

            var assetsChildren = _.template(this.tmplAssetsChildren, {items:this.collection.toJSON()});
            this.$currentTarget.find("ul").remove();
            this.$currentTarget.append(assetsChildren);
            this.delegateEvents();

            //console.log(this.collection.toJSON());

            return;
        }
    });

    return Catalog;
}
);

This is my console log:

View - BrowseDocuments.render catalog.js:126
View - BrowseDocuments.createDocument catalog.js:117
View - App.createDocument catalog.js:54
View - App.renderDocumentEditor catalog.js:64
Collection - AssetsList.parse catalog.js:30
Uncaught TypeError: object is not a function

It seems that i have problems on my Collection in my App.renderDocumentEditor view method.

renderDocumentEditor: function(name) {
    console.log("View - App.renderDocumentEditor");
    this.$el.find("#docs-browser").remove();
    this.$el.append(this.tmplDocumentEditor);
    this.AssetsBrowserSubView.renderDocumentName({name:name});
    // collection.fetch() throws Uncaught TypeError: object is not a function
    this.AssetsBrowserSubView.collection.fetch();
}

I’ve had the same problem here and I’ve solved it by setting every element of the json Array into it’s Collection‘s Model in for statement:

updateMainRequest: function(data){
    var data = this.model.toJSON();

    console.log("View - App.updateMainRequest");
    //console.log(data.documents);

    this.UserBarSubView.model.set(data.userdata);

    var documents = [];
    for (var i = data.documents.length - 1; i >= 0; i--) {
        documents.push(new CatalogModel.Document(data.documents[i]));
    };
    this.DocumentsBrowserSubView.collection.set(documents);
}

Probably I’m missing something on how the Collection should be used, I can’t believe I have to set every element of the array i pass into a Model instance before using the Collection method set.

If yes, how should I handle response of Collection.fetch requests to the server?

Solution

Answered By: Anonymous

You simply misunderstood the model key of Backbone Collections. It is supposed to be a Model, not an instance of a Model. So:

this.model = new CatalogModel.Asset();

should be

this.model = CatalogModel.Asset;

(and there’s therefore no reason to put it in the initialize method).

Now, about why. The goal is to give Backbone Collections (the constructor of) their model so they can do what you didn’t allow them to do: convert an object into model(s).
You surely have realized where your Uncaught TypeError: object is not a function comes from now: Backbone is trying to use the value of the model key when you use set or fetch: var model = new this.model(attrs, options);. In your case, this.model is simply an object, so the new operator naturally throws an error telling you you’re trying to use it with an object, and not a function.