I have the following template setup displaying a list of items, and wrapping each list in its own controller:
{{#each controller itemController="contact"}}
<div class="contact-entry">
<div class="title" {{action toggle on="click"}}>{{title}}</div>
{{#if showDetails}}
<div class="details">
<div>{{safe details}}</div>
</div>
{{/if}}
</div>
{{/each}}
The main controller is an ArrayController called ContentsController, and each item is wrapped in an ObjectController called ContentController. The content of the ContentsController is set explicitly in the route (I've simplified the data):
App.ContactsRoute = Em.Route.extend({
model: function() {
return [{'title': 'first'}, {'title': 'second'}];
}
});
This works really well. However if I navigate to another path and then back again, the settings on the ContentController don't persist. What happens is that the model data gets reloaded, and I assume a ObjectController gets created for each of the list items. Incidentally this is not the case for the ContentsController, which keeps its settings.
What is the solution to preventing ember of creating new ContentController for every list item every time I access the page?
I'm assuming your reference to ContentController is really ContactsController since you are using itemController="contact" in your #each block.
What kind of data are you trying to persist? The showDetails flag? The ContactControllers are going be created and destroyed anytime you exit / enter the route and there isn't anyway I know of to keep those around.
The ContactsController keeps its properties because its a singleton controller generated because you have a ContactsRoute.
Related
I'm working on an Ember.js application and have a table of devices, where I would like each listed device to open a modal dialog, when clicked, using that specific device as a model for the dialog.
The official documentation is slightly vague on how to do this, so I've been doing some guessing. I tried to pass the id of each device as a parameter inside the template:
{{#each}}
<button data-toggle="modal" data-target="#modal" {{action 'openViewModal' 'viewDeviceModal' id}} class="btn btn-default btn-xs">View details</button>
{{/each}}
{{id}} works as intended elsewhere in the template.
Now, inside the route, I put this:
actions: {
openModal: function(modalName, id) {
this.controllerFor(modalName).set("model", this.store.find('device', id));
return this.render(modalName, {
into: "application",
outlet: "deviceModal"
});
},
This gives me the following error:
"The value that #each loops over must be an Array. You passed (generated devices controller)"
Presumably, there is some confusion with the model of the list of devices (#each) and the model of the modal dialog. The modal dialog does not have #eachinside it.
I also lack a means to find out if my variables actually are what they are supposed to be. console.log does not work. I have not yet read all the documentation on debugging ember, so I'm hoping there will be some pointers there. Meanwhile, any help on how to get my modal dialog models to work would be greatly appreciated.
This is not a problem with your each loop, but with your model. You're setting the model for the controller as a single record when it looks like it expects an array of records. Change the first line of your action to this:
this.controllerFor(modalName).set("model", [this.store.find('device', id)]);
Also, as a tip, don't load the record from the store again when you already have it. Just pass the whole record in the action helper:
{{action 'openViewModal' 'viewDeviceModal' this}}
Then your action handler can look like this:
openModal: function(modalName, record) {
this.controllerFor(modalName).set("model", [record]);
(Note: I am using Ember version 1.0.0-rc.3)
I'm trying to catch the 'click' of a {{linkTo}} using a view, so that I can do additional stuff (basically scroll the list of users in the sidebar) besides merely loading the new template. Me being relatively new to this (but having read the documentation!), I thought the following would just work:
"users" template:
{{#each user in users}}
{{#view App.ClickView}}
{{#linkTo user user}}{{ user.name }}{{/linkTo}}
{{/view}}
{{/each}}
the view code:
App.ClickView = Ember.View.extend({
click: function(evt) {
// do stuff
}
});
and for context, the layout template:
<div id='sidebar'>
{{#each user in users}}
{{#linkTo user user}}{{ user.name }}{{/linkTo}}
{{/each}}
</div>
<div id='main'>
{{ outlet }}
</div>
Referring back to the users template, you can see that each {{linkTo}} is contained within a view. I'm expecting for a click on that {{linkTo}} to therefore bubble up to, and caught by the view (App.ClickView). Unfortunately, it doesn't. It seems like the click is somehow not being bubbled up to the view when it's happens on a {{linkTo}}... What should I do?
Note #1:
If I replace the {{linkTo}} (only in div#main! I don't intend to replace the ones in div#sidebar) with an <a> element, it works, and the click gets caught by the view. However, I'm not so sure that i want to go down this route (I'd have to replicate the functionality of the {{linkTo}}!). And I'm thinking that there ought to be a better way to do this. Is there?
Note #2:
*Note that I'm also aware that i can put my intended "do stuff" code in renderTemplate() of the UserRoute, but the problem with that is that the effect will happen for every link to that route (including the ones in the sidebar - which is not what I want). I want the scroll to only trigger for specific {{linkTo}}s - specifically the {{linkTo}}s in div#main.
I would suggest using an anchor (<a>) tag with {{action ... target="view"}} in it instead of linkTo, apply your conditional logic in the view, and then if appropriate, re-send to the controller (this.get('controller').send(actionName), let it bubble to the router, and do a transitionTo in a router event handler.
i try to create my first ember.js app. A calendar-
my day model
App.Day = Ember.Object.extend({
today : null,
dayNumber : null,
addEvent : function() {
console.log(this);
$("#myModal").modal('show');
}
});
the html view
<div class="cal">
{{#each App.DayList}}
{{#if this.today}}
<div class="day today" {{action "addEvent" target="model" }}>
{{#with this as model}}
<span class="text">{{this.dayNumber}}</span>
{{/with}}
</div>
{{else}}
<div class="day" {{action "addEvent" target="model" }}>
{{#with this as model}}
<span class="text">{{this.dayNumber}}</span>
{{/with}}
</div>
{{/if}}
{{/each}}
</div>
so on click on day i show the bootstrap dialog and I wont to load extern data, but I need a information about clicked day.
My understanding is I create a view
App.DayDetails = Ember.View.extend({
});
and inside this view I send an ajax request, but how to get information about clicked day inside this view?
You should almost never be doing any AJAX in a view.
Views do two things:
(1) draw themselves
(2) respond to UI events (clicks, typing, etc)
Your view should get its contents from a controller, in this case I suppose App.DayController or DayDetailsController. (that's another thing, it's best practice to end your subclasses with View or Controller, etc, so its obvious at a glance what they do).
Where the controller gets that data from is where things might get complicated. Ideally, in a mature app, you'd have a data store (a combination—in concept—of your server-side database and ActiveRecord, if you use rails) that would be queried. Simplistically, however, you could have the controller be responsible for using jQuery to manually handle an ajax request. So long as we're taking short-cuts, you could put such a call in a number of place, (a singleton controller, a day-specific item controller, the day model itself), just NOT the view. And it's important when taking these sorts of short-cuts to limit the contagion... all you should be doing with the manual ajax is fetching the JSON and then immediately and expeditiously getting it back into the ember ecosystem by setting it as the content of an array controller. I.e., no going one or two steps further by trying to insert the data into a view manually or whatnot. Don't fight Ember, if you can avoid it.
A few things:
(1) Your use of this is superfluous, as are the {{with}} statements. Inside an {{each}} block the context will be the current object (or its wrapping controller, if you're using itemController) in the iteration. (UNLESS you use "x in y" syntax, in which case the context remains the controller)
(2) The model should NOT be attempting to modify the DOM. Instead, rely on bindings and your controllers to coordinate UI changes. What you might want to do is have a App.DayController that you can put addEvent on, and then in your {{each}} use itemController="App.DayController".
App.DayController = Ember.ObjectController.extend({
addEvent: function () {
// ...
}
});
Then, the context for each loop in your {{each}} template will be each individual day controller. The controller will automatically be the target and context for the views so your template would look like this:
{{#each App.DayList itemController="App.DayController"}}
<div {{bindAttr class=":day today"}} {{action addEvent}}>{{dayNumber}}</div>
{{/each}}
(the : in :day means that day will always be a class, but today will only be a class if the today property on the context is truthy)
Because each day sends addEvent to its own controller, there's no need for figuring out what day to load.
The problem is as follows:
In our application we have several buttons, navigation icons etc., which we want to be 'selected' when they have been clicked. We can have multiple elements marked at the same time.
The secondary reason for me wanting to do this is that when I read the new Guides on emberjs.com I get the feeling that templates should be used more than stated before and that templates should have the responsibility of rendering the DOM, while the views should be used to handle sophisticated events (if any) or to create common/shared components to be reused in the application.
Currently the view is handling this:
app.NavView = Ember.CollectionView.extend({
...
itemViewClass: Ember.View.extend({
...
classNameBindings: ['isSelected:selected']
isSelected: function () {
return this.get('controller.selected') === this.get('content');
}.property('controller.selected')
})
});
But that is all the View basically is doing, I would like to drop the entire View and just use a template for this
I have tried with a template approach, and dropped the entire View concept.
<div id="main-menu">
{{#each content}}
<div {{bindAttr class="controller.isSelected:selected"}}>
{{{iconsvg}}}
{{name}}
</div>
{{/each}}
</div>
But my problem here of course is that bindAttr doesn't know about the context it’s in, and cannot 'send' this to the isSelected property on the controller to evaluate if it is this element that is selected or not.
Is there a good solution to do this without a view, or am I forced to use a view?
Or am I thinking the design part and responsibility of Templates/views/controllers wrong?
Any response is appreciated!
In the current documentation: http://emberjs.com/guides/templates/displaying-a-list-of-items/ there is a mention explaining how to use the {{each}} helper which doesn't override the current context.
In your case, this would be something like:
<div id="main-menu">
{{#each item in controller}}
<div {{bindAttr class="isSelected:selected"}}>
{{{item.iconsvg}}}
{{item.name}}
</div>
{{/each}}
</div>
Note I have remove the reference to 'controller' in the {{bindAttr}} since I assume it's an ember controller, then it's the current context, so basically isSelected is equivalent to controller.isSelected
Trying to figure out the "ember best practices" for my app, regarding MVC. also for reference, I'm using ember-data, ember-layout, and ember-route-manager.
I'll use User as an example:
what I feel like I want to do is to get a User model from the database... then wrap it in a UserController, and set the model on a "content" property... then in a View, I want to bind to the controller for some functionality, and to the controller.content for model-level data. so a controller might look something like:
App.UserViewController = Em.Object.create({
content: userRecord,
isFollowingBinding : 'content.you_follow',
toggleFollow: function() {
make server call to change following flag
}
});
then the view could bind to the {{controller.content.name}}, or {{#if controller.isFollowing}}, or {{action "toggleFollowing" target="controller"}}
but say I get a list of User models back from the database... I feel like what should happen is that each of those models should be wrapped with a controller, and that should be returned as a list... so the view would have a list of UserControllers
Incidentally, I've done this... and it is working nicely.... except that everytime I reload the list, I wrap all of the new model objects with new controllers... and over time, the # of controllers in memory get larger and larger. on my base Controller class, I'm logging calls to "destroy", and I dont see it ever happening
when it comes to Em.View... I know that everytime it is removed from the screen, .destroy() gets calls (I am logging those as well). so if I were to move my code into a view, i know it will get destroyed and recreated everytime... but I dont feel like the functionality like toggleFollow() is supposed to be in view...
SO QUESTIONS:
is this how MVC is supposed to work? every instance of a model wrapped in a controller for that model? where there could be lots of controller instances created for one screen?
if I go down this approach, then I'm responsible for destroy()ing all of the controllers I create?
or is the functionality I've described above really meant for a View, and them Ember would create/destroy them as they are added/removed from the screen? also allowing template designers to decide what functionality they need (if they just need the {{user.name}}, theres no need to instantiate other controller/view classes... but if they need a "toggle" button, then they could wrap that part of the template in {{#view App.UserViewController contentBinding="this"}} )
I re-wrote this a few times... hopefully it makes sense....
I wouldn't wrap every user into an own controller.
Instead I would bind the user to a view, say App.UserView and handle the action toggleFollow on that view. This action will then delegate it's action to a controller which will handle the server call, see http://jsfiddle.net/pangratz666/hSwEZ/
Handlebars:
<script type="text/x-handlebars" >
{{#each App.usersController}}
{{#view App.UserView userBinding="this" controllerBinding="App.usersController"}}
{{user.name}}
{{#if isFollowing}}
<a {{action "toggleFollowing"}} class="clickable" >stop following</a>
{{else}}
<a {{action "toggleFollowing"}} class="clickable" >start following</a>
{{/if}}
{{#if user.isSaving}}saving ...{{/if}}
{{/view}}
{{/each}}
</script>
JavaScript:
App.usersController = Ember.ArrayProxy.create({
content: [],
toggleFollowing: function(user) {
user.set('isSaving', true);
Ember.run.later(function() {
user.toggleProperty('you_follow');
user.set('isSaving', false);
}, 1000);
}
});
App.UserView = Ember.View.extend({
isFollowingBinding: 'user.you_follow',
toggleFollowing: function() {
var user = this.get('user');
var controller = this.get('controller');
controller.toggleFollowing(user);
}
});