selection attribute in Ember.select not working within a loop - ember.js

I have select view within a loop, and I wanted to set the default selection on the drop down. I tried setting "value" attribute as well as "selection" attribute but nothing worked for me. I was trying to create jsbin to demonstrate the issue, but then it is giving me completely different issue which I don't see in my dev code though.
My controller is defined like :
App.AnswerController = Ember.ObjectController.extend({
answerLayouts: function () {
return this.get('store').findAll('layout');
}.property(),
selectedAnswerLayout: null,
initialize: function () {
this.set('selectedAnswerLayout', this.get('store').find('layout', this.get('id')));
}.on('init')
});
and in the template I am doing:
<table>
{{#each answers itemController="answer"}}
<tr>
<td>{{name}}</td>
<td>{{view Ember.Select
content=answerLayouts
optionValuePath="content.name"
optionLabelPath="content.displayName"
class="form-control"
prompt="Answer Layout"
selection=selectedAnswerLayout}}
</td>
</tr>
{{/each}}
</table>
and does't see answerLayouts as an array, but when I check {{answerLayouts.length}} it returns 3!
Here is a jsbin link that demonstrates the issue: http://jsbin.com/AcUPIpEl/1/

It's an issue with the old version of Ember, it was fixed somewhere between 1.0+ and 1.2
http://emberjs.jsbin.com/ODaKIjIw/1/edit

Ok had to do things bit differently to get things working. Rather than defining "answerLayouts" as a property, I defined it as an array and when the controller gets initialized, I populated the array and set the selectedAnswerlayout there like this:
App.AnswerController = Ember.ObjectController.extend({
answerLayouts: Ember.A(),
selectedAnswerLayout: null,
initialize: function () {
var self = this,
selectedlayoutId = this.get('id');
this.get('store').find('layout').then(function(data){
data.forEach(function(layout){
self.get('answerLayouts').pushObject(layout);
if(layout.get('id') === selectedlayoutId){
self.set('selectedAnswerLayout',layout);
}
});
});
}.on('init')
});
Here is the working jsbin link : emberjs.jsbin.com/ODaKIjIw/3.
I have realized that when we can define things in init, it's best to do so there. I have had issues with bindings when relying on computed property before. Lesson learned :)

Related

Accessing model data in router when using a view

I am looking for a way to access model data in a route when using a view to display model attributes.
Example
Template
<h2>New post</h2>
<form {{action save model on="submit"}}>
<label>Title</label>
{{input type="text" value=title placeholder="title" id="title"}}
<label>Text</label>
{{view "tinymce" value=text }}
<button>Post</button>
</form>
View Template
<textarea id="tinymce">
</textarea>
View
export default Ember.View.extend({
templateName: 'views/tinymce-textarea',
didInsertElement: function() {
tinymce.EditorManager.execCommand('mceRemoveEditor',true, 'tinymce');
tinymce.EditorManager.execCommand('mceAddEditor',true, 'tinymce');
}
});
Router
export default Ember.Route.extend({
....
actions : {
save : function(model) {
if (!model.get('title').trim() || !model.get('text').trim()) {
return;
}
model.save().then(this.onSuccessfulSave.bind(this), this.onFailedSave.bind(this));
}
}
});
Now, obviously this doesn't work, since model.text is never bound in the view, like it would be if I were to use the textarea template helper:
{{textarea value=text placeholder="text" id="text"}}
But this is just one of many (many) ways I have tried to get this to work, and I am at a complete loss as how one would access model attributes in the route when using a view. And it does seem like a pretty common usecase to me too.
I have failed to find information regarding this on SO or anywhere else, so if anyone is able to help me, thanks in advance! / AS.
So one of the main things that you're missing out is binding the view to the controller. This is actually really straight forward to do, but without it Ember doesn't know that it should propagate changes between the two. The first thing I would do is this:
{{view "tinymce" valueBinding="text" }}
This says that the views value will be binded to the controller's text value. Whenever view's value is updated, it will propogate to the controller and vice versa.
The next item to take care of is actually binding the value in the view. All you need to do is tell the input to bind it's value to the view's value. This can be done like this
{{textarea value="view.value" placeholder="text" id="text"}}
Try this out, and you can use this jsbin that I created as an example:
http://emberjs.jsbin.com/qanudu/26/
If you have any other questions just let me know, but this should solve your issues!

Programmatically setting computed property of an itemController

I have a template with the following code:
{{#each types itemController='type'}}
<div class='col checkbox'>
<label>
{{input type='checkbox' checked=isSelected disabled=notAllowed}}
<span {{bind-attr class='isSelected'}}>{{name}}</span>
</label>
</div>
{{/each}}
types is set in setupController:
this.store.find('type').then(function(types){
controller.set('types', types);
});`
//Having 2 other models here that I am setting and having an itemController for, exactly in the same fashion as types.
for the ArrayController which has the itemController.
NOTE: To clarify, I am using and setting 3 different models, which work pretty much in the same way as type, that makes this a bit more complicated.
Then the itemController itself:
App.TagController = Ember.ObjectController.extend({
isSelected: function(key, value){
//bunch of code that does some stuff and returns true or false depending on value
}.property()
});
App.TypeController = App.TagController.extend();
Now the problem: I have a resetbutton that should deselect all checkboxes and remove the span classes.
I would have thought about using an action (in the ArrayController) that sets all the isSelected properties to false, but I don't seem to be able to find a way to access and manually set that itemController computed property.
One thing I tried in the ArrayController is the following:
actions: {
resetFilters: function(){
this.get('types').forEach(function(type) {
console.log(type.get('isSelected'));
//type.set('isSelected', false);
});
}
}
But unfortunately this returns undefined. And using jQuery manually to remove the class and uncheck the checkbox seems to work the first instance, but the problem is, the computed property doesn't get updated and that messes things up.
Any idea how I can achieve what I want?
If anything is unclear let me know and I will do my best to clarify.
Thank you.
You are setting controller.types, this will not work with itemController. You should always be setting an array controller's content property.
The following should work:
controller.set('content', this.store.find('type'));
Then to set the isSelected:
controller.setEach('isSelected', false);
This assumes that controller is an instance of an ArrayController that has an itemController set in it's definition, e.g.
App.TypesController = Em.ArrayController.extend({itemController: 'type'});
store.find returns a PromiseArray, so it should be resolved first. You can set the types as follows in setupController:
this.store.find('type').then(function(types){
controller.set('types', types);
});
Or you can resolve types in the reset:
this.get('types').then(function(types) {
types.forEach(function(type) {
console.log(type.get('isSelected'));
});
});
I would recommend the first one though.

How can I use holder.js inside an #each loop in Handlebars (Ember.js) template?

I'm looping through an array of objects in an Ember.js Handlebars template and trying to display a placeholder image for each using holder.js.
Outside of the #each loop context, holder.js renders the placeholder image as expected:
<img data-src="holder.js/100x100" src='' alt='person image' />
{{#each person in controller}}
person.name
{{/each}}
When inside the #each loop, no placeholder images appear:
{{#each person in controller}}
<img data-src="holder.js/100x100" src='' alt='person image' />
person.name
{{/each}}
Perhaps there's something I'm not understanding about how #each loops work, but is there a trick to getting placeholder images to appear here?
The problem is Holder.run() is called before Ember loops through all your data, so you have to call it yourself again at a later point.
You could try adding
Em.run.schedule('afterRender', null, function () { Holder.run(); })
or
Em.run.next(function () { Holder.run(); })
to the renderTemplate hook of your route. (Even better would be to add it after you know your controller has been loaded with all your data.)
I just want to be a bit more explicit in case anyone like me runs into similar problems or gets themselves confused with how it works.
First, add a View for your template if you don't have one. If you're working with the MushroomsRoute, create a MushroomsView. Inside your view, do something like this:
App.MushroomsView = Ember.View.extend({
didInsertElement: function() {
Ember.run.next(function() {
Holder.run();
})
}
});
And that should work -- or at least it does with Ember 1.0.0.

Controller not seeing the updated model - asynchronous handling

I have a very simple requirement but like with many things in Ember.JS, I'm banging my head against the wall trying to get it implemented.
I have an overview screen where a couple of records are displayed in a table.
To render the overview screen I'm using the following Route
App.LocationsIndexRoute = Ember.Route.extend({
setupController: function(controller) {
var locations = App.Location.find();
controller.set('content', locations);
},
renderTemplate: function() {
this.render('locations.index',{into:'application'});
}
});
This is working fine.
I would now like to conditionally render the overviewtable.
If records are present render the table.
If no records are present display a message.
I tried implementing this using the following controller.
App.LocationsIndexController = Ember.ArrayController.extend({
locationsPresent: function() {
var model = this.get('content');
return model.content.length > 0;
}.property()
});
and the following template
{{#if locationsPresent}}
<table class="table table-hover">
<tr>
<th>Latitude</th>
<th>Longitude</th>
<th>Accuracy</th>
<th></th>
<th></th>
</tr>
{{#each location in model}}
<tr>
<td>{{location.latitude}}</td>
<td>{{location.longitude}}</td>
<td>{{location.accuracy}}</td>
<td>{{#linkTo locations.edit location}}Edit{{/linkTo}}</td>
<td><button {{action removeItem location}}>Delete</button></td>
</tr>
{{/each}}
</table>
{{else}}
No locations present.
{{/if}}
The computed locationsPresent property is called once, before the page is rendered. At that time I assume that the model is still being loaded as the length = 0.
When the page is rendered, the locations from the App.Locations.find() are available but the locationsPresent is not called anymore, meaning the page decided to render the No locations present. message.
I went through the Managing Asyncrony in Ember page and assumed that the computer property locationsPresent would be updated if the underlying model changed (if it was completely loaded) as the page states :
Using a computed property for author eliminated the need to explicitly invoke the computation in a callback when the underlying property changed.
I'd love to know what I'm doing wrong and how I can fix this but more importantly why I seem to be missing some of these core concepts of Ember.JS. If somebody can point me where in the docs / guides this is explained properly I'd love to know.
I think it is a easy fix. You need to add the property you are observing. like so:
locationsPresent: function() {
var length = this.get('content.length');
return length > 0;
}.property('content.#each')
adding the #each is necessary if locationsPresent needs to recalculate wen content is added. I think you can also observe 'content.isLoaded'

Ember.js - Using {{#if}} around {{bindAttr}} with shared condition?

I'm on Ember-1.0.0-pre2 and I seem to be having trouble using an {{#if}} statement around an element which has a {{bindAttr class="..."}} and the binding conditions are the same. I.E. the if statment and class binding are to the same controller attribute. See code:
<button {{action "toggleShow" target="controller"}}>Toggle Visibility</button>
{{#if show}}
<div {{bindAttr class="show:red:green"}}>test</div>
{{/if}}
http://jsfiddle.net/y49ch/10/
If you click the "Toggle Visibility" button several times you'll notice you get a the common error that says: "Something you did caused a view to re-render after it rendered but before it was inserted into the DOM. Because this is avoidable and the cause of significant performance issues in applications, this behavior is deprecated ..."
At first look that seems stupid, but that's a very primitive example of my problem. In my case, there is a computed property on the end of both bindings (if and class attribute). In both cases the computed properties share a common dependent key. When that common dependent key changes it causes both helpers to be update and thus the error.
Is this a bug? I can guess what's happening here, but it seems like I should be able to do this safely.
EDIT: The above is a primitive example of the problem I'm having. It's meant to show it in a very simple way. Below is a more complex example.
Template:
<button {{action "toggleValue" target="controller"}}>Toggle Value</button><br>
{{#if greaterThanTen}}
<div {{bindAttr class="isOdd:red:green"}}>test</div>
{{/if}}
Javascript:
App.myController = Ember.Controller.create({
value: 10,
greaterThanTen: function() {
return this.get('value') > 10;
}.property('value'),
isOdd: function() {
return this.get('value') % 2 === 1;
}.property('value'),
toggleValue: function() {
this.set('value', (this.get('isOdd') ? 10 : 11));
}
});
http://jsfiddle.net/y49ch/16/
I see it now. Your original code had both points watching the same property which got me a little confused, but now it makes more sense. I can't really get what's going on, but I suspect it might have something to do with the runloop.
I've changed your code a little (see this jsfiddle) so that div is now a child view. Some of your properties were moved from the controller to the view (does your spec allow these guys to be at the view or does it have to be at the controller? unless I missed something only the view should be concerned about isOdd and toggleValue at this point) and the css is bound through classNameBindings watching for the value property that is bound to the parent view.
App.myController = Ember.Controller.create({
value: 10,
greaterThanTen: function() {
return this.get('value') > 10;
}.property('value')
});
App.MyView = Ember.View.extend({
templateName: 'my-view',
valueBinding: 'controller.value',
toggleValue: function() {
this.set('value', (this.get('isOdd') ? 10 : 11));
},
isOdd: function() {
return this.get('value') % 2 === 1;
}.property('value'),
ChildView: Em.View.extend({
classNameBindings: 'parentView.isOdd:red:green'
})
});
Now, the template looks like this:
<script type="text/x-handlebars" data-template-name="my-view">
<button {{action "toggleValue"}}>Toggle Value</button><br>
{{#if greaterThanTen}}
{{#view view.ChildView}}
test
{{/view}}
{{/if}}
</script>
Since the default tag for the View is div, it renders the same html, and it totally acts as a different view and prevents unecessary re-render.
Edit: Just as proof of concept, I've added a button to add to the value instead of just toggle so you can actually see the color changing after it gets visible. Here's the fiddle
Let me know if this is good for you