Cross referencing of 2 models - javascript

I have 2 models which are cross referencing each other. This could look like this:
MainModel:
define(
[ 'durandal/app', 'durandal/plugins/router', 'models/Shell', 'models/EditModel' ],
function (app, router, shell, editModel) {
//...
return {
//...
// This function should be accessible by the EditModel
update: function() {
//...
},
showEditView: function() {
// Initialise the EditModel with some data and show the according view afterwards
editModel.init('set some important stuff here...');
router.navigateTo('#/EditView');
}
//...
};
}
);
EditModel:
define(
[ 'durandal/app', 'durandal/plugins/router', 'models/Shell', 'models/MainModel' ],
function (app, router, shell, mainModel) {
//...
return {
//...
// This function should be accessible by the MainModel
init: function() {
//...
},
showMainView: function() {
// Update the the MainModel with some data and show the according view afterwards
mainModel.update('set new data here...');
router.navigateTo('#/MainView');
}
//...
};
}
);
Unfortunately this is not working. If I load my page on the MainView and call showEditView, the variable editView is known and everything works fine but then the variable mainModel in the EditModel is undefined and therefore the call mainModel.update(...) fails.
Same thing happens if I load my page on EditView but in the "opposite direction" (var mainModel in the EditModel is known, but editModel in the MainModel is undefined).
Is this a known issue and if so: How can i circumvent it?
I also posted this question in Durandals Google Group
Thanks

Check requierejs documentation for circular dependencies http://requirejs.org/docs/api.html#circular.
Circular dependencies are rare, and usually a sign that you might want
to rethink the design. However, sometimes they are needed, and in that
case, use require() as specified above.
For main.js add require as dependency and then explicitly require models/EditModel should do the trick. Either replicate that for the other modules or rethink the design ;-).
define(
[ 'require', 'durandal/app', 'durandal/plugins/router', 'models/Shell', 'models/EditModel' ],
function (require, app, router, shell, editModel) {
//...
return {
//...
// This function should be accessible by the EditModel
update: function() {
//...
},
showEditView: function() {
// Initialise the EditModel with some data and show the according view afterwards
require('models/EditModel').init('set some important stuff here...');
router.navigateTo('#/EditView');
}
//...
};
}
);

Related

Dealing with undefined dependencies in require.js

I am trying to modify my code such that it works with Require.js but i am running into an issue where some dependencies are undefined where i believe they should be.
A minimal working example is given by the below files:
main.js:
// Configure require.js
requirejs.config({
baseUrl: "js/app",
});
require(["app"], function(app) {
app.init();
});
app.js:
define( ["container", "renderer"], function ( CONTAINER, RENDERER) {
return {
init: function () {
CONTAINER.init();
RENDERER.init();
console.log(CONTAINER, RENDERER)
},
}
});
container.js:
define( ["renderer"], function ( RENDERER ) {
// define container
var container = new Object();
return {
container: container,
init: function() {
console.log(RENDERER)
},
}
});
renderer.js:
define( ["container"], function ( CONTAINER ) {
var renderer = new Object();
return {
renderer: renderer,
init: function() {
console.log(CONTAINER);
},
}
});
The problem is that in renderer.js CONTAINER is undefined. The console shows this when run in a browser:
Why is CONTAINER undefined in renderer.js while it is defined just fine in app.js?
Circular reference between container and renderer.
I recall that require.js specifically does not allow such circular references, where container requires renderer and renderer requires container.
If you want the circular reference between the objects you can get around require's restriction by having app set a property in renderer, or in container, for example, by calling a function like ...
CONTAINER.init(RENDERER)
...from within App...
Obligatory verbose warning about the evils of circular reference omitted for brevity.

Using requirejs with retinajs

I am using requirejs and am calling in retinajs as a plugin. I am using the shim along with a jQuery dependancy:
....
'plugins/retina.min': {
'deps': ['jquery']
}
....
I then init my application:
requirejs(['./main'], function(App) {
App.init();
});
"main.js":
define(['jquery', 'foo', 'bar', 'plugins/domReady!', 'plugins/retina.min'], function($, foo, bar, retina) {....});
My logo on my page is getting updated correctly, however it seems I am running into a timing issue. Further down the page (or even subsequent page views) the script is getting executed before the page is ready.
Retina.js auto-exectues so there isn't a method to initialize per say. Is there a way to "call" a jquery plugin that auto-executes with require js?
This is wrong, but I think this is something along the lines of what I need:
define(['jquery', 'foo', 'bar', 'plugins/domReady!', 'plugins/retina.min'], function($, foo, bar, retina) {
var App = {
init: function() {
retina.init(); // This doesn't exist
<script src="/plugins/retina.js"></script> // Not even close to valid, but this is what I need.
}
};
return App;
});
Thank you for your time and suggestions!
Try this:
define(['jquery', 'foo', 'bar', 'plugins/domReady!'], function($, foo, bar) {
var App = {
init: function() {
require(['plugins/retina.min'], function(){
// This is straight from retina.js's source: https://github.com/imulus/retinajs/blob/master/src/retina.js#L142
if (Retina.isRetina()) {
Retina.init(window);
}
});
}
};
return App;
});

requirejs including module that returns an object in another similar module

I am facing a weird issue in a requirejs/backbonejs application. I have a Globals.js file which returns reusable utilities. It looks something like this.
define(
['newapp/routers/index', 'newapp/controllers/index', 'newapp/utilities'],
function(Router, Controller, Utilities) {
return {
router: new Router({controller: Controller}),
utilities: Utilities,
navigate: function(path, opts) {
this.router.navigate('app/' + path, opts);
}
}
})
When I require this module in modules that return Backbone Views, it is able to resolve Globals to an object and call methods on it. However, when I try to include it in a module that returns another object, it's resolved to undefined.
For example the code below is able to resolve Globals to the properties it exposes
define(
['marionette', 'templates', 'newapp/globals', 'newapp/views/Loader'],
function(M, T, Globals, mixins){
"use strict";
return M.ItemView.extend(
_.extend({}, mixins, {
template: T.brandPageInfo,
events: {
'click #getProductsForBrands': 'getProductsForBrands',
'click button[id^="goto__"]': 'actionOnGotoButtons'
},
onRender: function() {
this.flatIconsOnHover();
},
getProductsForBrands: function(e) {
e.preventDefault();
var searchQuery = this.model.get('name');
Globals.navigate('search?q=' + searchQuery, {trigger: true});
}
})
)
})
But the code below gives an error: Globals is undefined
define(
[
'newapp/collections/Boards', 'newapp/globals'
],
function(
BoardsCollection, Globals
) {
var boardsList;
return {
ensureBoardList: function() {
var defer = $.Deferred();
if (!boardsList || (boardsList && !boardsList.length)) {
boardsList = new BoardsCollection();
boardsList.fetch({
data: {_: (new Date()).getTime()},
success: function (boardsListCbData) {
boardsList = boardsListCbData;
defer.resolve(boardsList);
}
})
} else {
defer.resolve(boardsList);
}
return defer.done(function (boardsList) {
//make the boardsList usable for direct UI rendering by any view
return Globals.utilities.getFormattedBoardsCollection(boardsList);
});
}
}
})
How do I make Globals accessible in the second example?
Make sure you don't have any circular dependencies e.g.:
globals depends on newapp/controllers/index
newapp/controllers/index depends on the last module you displayed (we'll call it module M)
module M depends on global
Since each module depends on the other, the only thing RequireJS can do is set one of them to undefinedto "break the cycle" and get the other modules to load.
As far as I can tell, this is the most probable source of your problem, not the fact that you're returning another object.

method won't trigger when using requireJS

I have some issue with some requireJS setup. I posted a question before but the scope of the latest changed now.
I have some
requirejs.config({
paths: {
'tmpl': 'vendor/upload/tmpl.min'
}
});
require({
paths: {
'videoupload': 'vendor/upload/jquery.ui.videoupload'
}
}, ['js/main_video.js'], function (App) {
App.initial_video_upload();
});
and finally in main_video.js :
define(['tmpl', 'videoupload'], function () {
function initial_video_upload(tmpl, videoupload) {
'use strict';
$('#videoupload').videoupload({
//...some code
});
}
return{
initial_video_upload: initial_video_upload
}
}
);
This code works perfectly if I don't use requireJS (loading classically each file). In fact, when this code is triggered, I keep on having a message Uncaught TypeError: Object [object Object] has no method 'tmpl', this method is defined in tmpl.min.js. And this method is invoked in vendor/upload/jquery.ui.videoupload, as so
$.widget('videoupload', {
//...
_renderVideo: function (video) {
this._templateElement().tmpl({
id: video.id,
name: video.title
}).appendTo(this._listElement()).find(
this.options['delete-selector']
);
return this;
},
//...
How can I manage that ? (I had earlier an error time out message for this method tmpl, but it disappeared now, so I don't think this is it)
In the configuration object, the path is not the full path to the JS file BUT the path to the directory containing the JS file, so you may want to do something like this in the main_video.js file:
requirejs.config({
paths:{
'upload': 'vendor/upload'
}
});
define(['upload/tmpl','upload/jquery_videoupload'],function(tmpl, videoupload) {
function initial_video_upload(tmpl,videoupload){
'use strict';
$('#videoupload').videoupload({
//...some code
});
}
return{
initial_video_upload: initial_video_upload
}
}
);
And in the main app:
requirejs.config({
paths:{
'js': 'path/to/your/js/folder'
}
});
require(['js/main_video'], function(App) {
App.initial_video_upload();
});
There's a problem in the questions code, so this:
define(['tmpl', 'videoupload'], function () {
should become this:
define(['tmpl', 'videoupload'], function (tmpl, videoupload) {
The first one doesn't expose loaded dependencies to local variables of closure function, so that's might be a problem, although it's not very clear if it's the only one, from the provided code.
I would also like to mention, that it's not a good thing to use multiple requre.js configs, if you're intended to use optimizer. The configs will be overwritten by the last one, so it's a good idea actually to have only one config for the whole project.
Like this:
requirejs.config({
paths: {
'tmpl': 'vendor/upload/tmpl.min',
'videoupload': 'vendor/upload/jquery.ui.videoupload'
}
});

using Backbone JS boilerplate & code navigation

a newbe question:
I've downloaded the backbone boilerplate from https://github.com/david0178418/BackboneJS-AMD-Boilerplate it uses require.js and I wonder about the code navigation during development.
Here is my question:
let's say I have 2 views one extend the other like so:
View 1:
define([
'underscoreLoader',
'backboneLoader',
'text!templates/main.html'
],
function (_, Backbone, MainTemplate) {
"use strict";
return Backbone.View.extend({
template:_.template(MainTemplate),
initialize:function () {
this.render();
},
log:function(msg){
console.log(msg);
},
render:function () {
this.$el.append(this.template({}));
return this;
}
});
}
);
View 2:
define([
'underscoreLoader',
'backboneLoader',
'text!templates/other.html',
'views/main-view'
],
function (_, Backbone, MainTemplate,MainView) {
"use strict";
// how would you navigate to MainView (main-view.js)
return MainView.extend({
template:_.template(MainTemplate),
initialize:function () {
this.render();
},
render:function () {
this.log("my message");
this.$el.append(this.template({}));
return this;
}
});
}
);
Now when I develop (I use IntelliJ) I would like to middle click MainView on the extended view and navigate to the code without having to browse the project tree.
Is that possible using this boilerplate? is there a better approach or a better boilerplate?
I would really like Netbeans's navigator to show me all the methods:
var New_Controller = Backbone.View.extend({
el : null, ...
}
But I can't seem to get it to work. Google came up with something for #lends, but I can't even get Backbone.js to get loaded to the code hint cache.
I ended up installing WebStorm (I saw the IDE in all the egghead.io tutorials) to get the navigator to list all methods and properties.
FYI, Aptana Studio and Zend Studio showed nothing like Netbeans. And Eclipse IDE for JavaScript Web Developers only partially (impractical in real life) works; it flattens the entire hierarchy.
I found this to work fine for me:
the Backbone Objects are wrapped with my custom objects, which allows me to navigate code, extend objects and keep multiple files easily.
Here is how:
Object 1
function ItemModel() {
ItemModel.model = (
Backbone.Model.extend({
initialize:function () {
},
defaults:{
name:"item name"
},
log:function(){
console.log("inherited method");
}
})
);
return new ItemModel.model();
}
Object 2
function ItemModel2() {
ItemModel2.model = (
ItemModel.model.extend({
initialize:function () {
},
defaults:{
name:"item name2"
}
})
);
return new ItemModel2.model();
}
and in my app:
var App = {
item:new ItemModel(),
item2:new ItemModel2()
};

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