I am creating ember components for simple form elements with validations and proper styling with bootstrap. I am aware of ember validation libraries but I am doing this to better understand ember components.
Here is the jsbin link for the app.
http://jsbin.com/natuq/12/edit?html,js,console,output
How come I don't see and values? Is the property naming wrong or is it something else?
Thanks
The value property you are trying to log in App.AecFormComponent is actually a property on the App.AecInputComponent instance. That is why you don't see the value being logged.
You can observe this by adding the following observer (no pun intended):
App.AecInputComponent = Em.Component.extend({
logValueChange: function() {
console.log(this.get('value'));
}.observes('value'),
});
This is expected behavior because components create controller-like scope inside of their handlebars blocks. You could set up an Ember binding between the two properties to link them or bind the property of the input to view.parentView.value or something like that (though that's hacky).
Related
I have found that nice example of how to display notifications within ember [1]. After noticing it does not work so well with the current ember versions, I created a jsbin and fixed what seemed to be broken: http://emberjs.jsbin.com/decojele/1/edit
I was thinking about putting something like that into its own module, so it can be easily added to existing ember applications. However, the first thing that does not seem to be very suitable for something like this is that it relies on methods and fields (like the notifications array) that are kept within the application controller:
App.ApplicationController = Ember.Controller.extend({
notifications: Em.A()
// ....
//please see jsbin for the other stuff
})
This is picked up by a Collection view, which handles the actual rendering.
App.NotificationContainerView = Ember.CollectionView.extend({
contentBinding: 'controller.notifications'
// ....
//please see jsbin for the other stuff
});
As far as I currently understand how controllers work is that they depend on the currently active route and I so far haven't been able to put what currently is inside the ApplicationController into something more specific like a NotificationController. Is there a good way to do this? Or is this probably something I am just overthinking?
[1] http://aaron.haurwitz.com/#!/posts/growllike-notifications-with-emberjs
As described here [1], if render is used instead of the view helper, the appropriate controller is called as well. So, that actually seems to work: http://emberjs.jsbin.com/decojele/2/edit?html,js,console,output
[1] http://darthdeus.github.io/blog/2013/02/10/render-control-partial-view/
I have an ArrayController that uses associated itemControllers to track a checked property on the set of models (i.e. whether or not their checkbox is checked).
This part is currently working fine. When I come back to the route, I need to use some information off of the user model to "remember" which were checked.
How can I set the checked property on the specific itemController's? I can get references to the individual models that need "checking", but model.set('checked', true) doesn't seem to get picked up by the itemController in that scenario.
Any help would be appreciated!
From your array controller, iterate this and that will give you each individual itemController. Here's the basic concept
App.FooController = Em.ArrayController.extend({
someFunc: function(){
this.forEach(function(item){
item.set('checked', item.get('model.wasChecked'))
});
}
});
I am creating an Ember application as an add-on to some HTML returned from the server. I need this HTML so that the site can be indexed by search engines, and also to speed up the initial page rendering for the users.
So my application consists of several Ember Views, appended to different DOM elements of the HTML generated by the server. I don't use master templates for routes, so I set renderTemplate function of each route to do nothing.
My Ember App is bound to body element and I can successfully append a custom view to an element down the tree. It works:
In this JSFiddle three last elements of the list are appended by Ember
But when I try to use linkTo helper in my template, I hit an error:
Uncaught TypeError: Cannot read property 'container' of null ember-latest.js:32224
which is in this function:
router: Ember.computed(function() {
return get(this, 'controller').container.lookup('router:main');
}),
In this JS fiddle I just add linkTo to the template, and it breaks everything
In general, can Ember work this way - having many Views scattered
over the HTML rendered by the server?
How can the example code be
fixed?
I've fixed your fiddle here, Check it out.
Seems like you are starter to Ember,
So here are some tips for you,
You should have an application template, which will be the root template and on which all the templates will be rendered.
You shouldn't access views using this.container.lookup, that is for debugging only.
You shouldn't append views to the DOM, it's the job of the framework to do.
By default your application will be appended to the body of the html, if you want it to be appended elsewhere, give the rootElement property when creating the application. Refer here for configuring your application.
The rootElement can be either a DOM element or a jQuery-compatible selector string. Note that views appended to the DOM outside the root element will not receive events. If you specify a custom root element, make sure you only append views inside it!
Don't access any controllers globally like App.itemsController.set("content", model), if you want to access another controller inside a route, use this.controllerFor, and to access inside another controller, use needs.
You need not create any controller instance like App.itemsController=Ember.ArrayController.extend({}).create();
The framework will take care of all these.
I found that I need to additionally bind the view and the container together to make this fiddle work
App.itemsView.set("controller", App.itemsController);
App.itemsController.set("container", this.container);
So the resulting working code snippet is here:
http://jsfiddle.net/ddegtyarev/6cBRx/6/
Again, let me reiterate that I'm building an hybrid Ember application - i.e. I have some HTML returned right from the server, and some appended by multiple Ember views in multiple places. This is why I have to manually create the views and bind them with controllers etc.
Assume you have the following routes in an Ember application.
App.Router.map(function() {
this.resource('series', function() {
this.resource('serie', { path: '/:serie_id' }, function() {
this.resource('seasons', function() {
this.resource('season', { path: '/:season_id' }, function() {
this.resource('episodes', function() {
this.resource('episode', { path: '/:episode_id' });
})
});
});
});
});
});
How would I link to a specific episode using the linkTo helper that Handlebars provides? In other words, how does Ember figure out what the other parameters of the URL should be, that is, the serie_id and episode_id? The documentation states that I should pass an episode model to the episode route as shown below.
{{#linkTo "episode" episode}}
This is to link to the following URL structure.
/series/:serie_id/seasons/:season_id/episodes/:episode_id/
When I use the linkTo helper like that, Ember throws an error telling me that it cannot call get with id on undefined. I assume that it uses the episode model to figure out what the serie_id and episode_id are and my guess is that the model needs to conform to a specific convention (structure or blueprint) for Ember to find these ids.
These are the aspects that I find most difficult about Ember. It isn't very transparent even if you use Ember in debug mode. Any pointers or references are much appreciated.
UPDATE 1: After some digging, I found out that the route's serialize method is a key element in accomplishing this. However, when I use the linkTo helper as illustrated above, the model passed to the route's serialize method is undefined for some reason (even though it is not when passed to the linkTo helper. The question that led to this discovery can be found here.
UPDATE 2: It turns out that the serieSeason route's serialize method receives the wrong model, an episode instead of a season, when the link is generated. It isn't clear, though, why it is receiving the wrong model. Where does the model parameter of the serialize method come from?
UPDATE 3: The linkTo helper works fine if I return static data from the serialize method of each route involved, which means that the linkTo helper isn't involved in the problem.
It turns out that the answer could be found in the properly documented source of Ember ... because that is what one does after searching the web for several days.
The answer is simple. The linkTo helper accepts more than one model. For each dynamic segment of the destination URL, you pass a corresponding model. Each passed model will become the model of the corresponding route in the destination URL. In the example that I describe above, this results in the following.
{{#linkTo "episode" serie season episode}}
The serie model will be passed to the serie route, the season model to the season route, and the episode model to the episode route. What confuses many developers is that the route's model hook isn't triggered when you use the linkTo helper. This isn't too surprising if you realize that the developer provides (or can provide) the model for the corresponding route by passing one or more models (or zero).
Because there isn't much documentation for deeply nested resources, it wasn't trivial to find out how the linkTo helper does its job under the hood. Diving in Ember's source definitely helps getting up to speed with the framework.
Playing around with ember, I found that sometimes the model is stored on the controller's content property, sometimes the model is directly available on the controller as well. I do not understand however, when this is the case.
Let me explain it by an example which I found when assembling my ember MVC.
Setup A - The start
I defined a custom Member object, corresponding MemberRoute, MemberView classes and a template with the name member.
The Member object had some attributes such as id, nickname, etc.
NOTE: no controller of the form MemberController was defined, thus by ember's convention, it provides the controller on its own.
Setup B - The customization
Same as setup A, but now there is a MemberController defined that contains some action methods that are triggered from within the template.
The strange behaviour (resp. what I do not completely understand)
in setup A, I can refer to the Member's attributes directly with {{id}} or {{nickname}}.
in setup B, I have to use {{content.id}} or {{content.nickname}}
As documented in ember's documentation, MemberView does
setupController : function(controller, member) {
controller.set('content', member);
},
So, could somebody help me to understand why the difference and where the difference is? Currently, my guess would be either
that the context of the template is different (possibly there is a code piece missing in the setup of the controller?)
or
the default controller that is provided by ember automatically, has some additional magic that is not directly avaiable for customized controllers.
Any help to understand this is highly appreciated. It already took my quite a while to come as far as this. I first thought it could be the modularization introduced by the project setup with requireJS (well, I still think that could have a influence). Ember is v1.0pre4.
Thanks in advance!
Patrick
So, could somebody help me to understand why the difference and where the difference is? Currently, my guess would be either
that the context of the template is different (possibly there is a code piece missing in the setup of the controller?)
or
the default controller that is provided by ember automatically, has some additional magic that is not directly avaiable for customized controllers.
It's hard to say for sure without seeing your code, but my best guess is that your MemberController extends Ember.Controller. The default provided by ember (in this scenario) would have been an Ember.ObjectController. If that's what you want, change your MemberController definition to:
App.MemberController = Ember.ObjectController.extend({
myProperty: 'value'
});
An objectController acts as a proxy to it's content property, typically that is an ember model. So if things are wired up correctly you should never need to access a model via the 'content` property. If you ever see something like:
{{content.id}} or {{content.nickname}}
it's a sign that you should change to an ObjectController. See EMBER GUIDES: REPRESENTING A SINGLE MODEL! for a more detailed explanation.
an ObjectController acts as proxy to the object set to the controller's content. When no controller is defined, Ember will create a controller for you and set its content by default to whatever object is returned by the model() function, if defined, in the route. The behaviour should be the same whether you define your own controller or let Ember define one for you
The default context in the template is the controller itself i.e. this = an instance of your controller or the generated one. When you try to access nickname in that context, Ember will first try to resolve it against the controller itself and if nothing is found, it resolves it against its content, i.e the object if you already manually set it to the controller's content.
Finally, there is no default implementation of the model() function in the Route except when you're using dynamic urls, say /foo/id that resolves against /foo/:id, Ember uses the id provided to load a Foo object with the id provided, thus providing a default implementation to the model() function. At the end it boils down to the same mechanism, only automated for your convenience.
I suggest you listen to this for more insights on how things are automated for you by Ember. But when it comes to the content being displayed, there is no magic you have to manually wire the content of the controller.