I am using ember and handlebars for template and I have a case where I need to give custom Ids to the element which is created using loops.
Something like:
{{#each item in list}}
<li {{bindAttr id="item.id"+item.name}}>item.text</li>
{{/each}}
i wanted my id to be a sum of strings id and name. e.g. if
id = 3 and name = summary
then it should render as
<li id="3summary">Summary</li>
You can't concatenate in Handlebars like that, instead you'll need to either create a Handlebars helper to do that, or create a computed property in the Ember.Object:
App.MyModel = Ember.Object.extend({
idName: function() {
return '%#%#'.fmt(this.get('id'), this.get('name').toLowerCase());
}.property('id', 'name')
});
Please see the JSFiddle for a working example: http://jsfiddle.net/u4th3/
Related
Is there a way to iterate over a view's context's attributes in EmberJS? I am using Ember-Data (https://github.com/emberjs/data) for ORM.
Lets say I use connectOutlets to register a UserView with a user that has attributes such as email, name, etc. In the connected Handlebars template, is there anyway that I can iterate over those attributes?
I basically need to build a generic view that can be reused with different models...
Ryan is right about the attributes, but it takes some doing to actually get where you're going. My examples here are using the latest RC1 Ember.
Here is an editor template that is model agnostic:
<script type="text/x-handlebars" data-template-name="edit_monster">
{{#if clientId}}
<h1>Edit Monster: {{name}}</h1>
<div>
{{#each metadata}}
<span class="edit-label">{{name}}</span>
<span class="edit-field">
{{view App.AutoTextField typeBinding="type" nameBinding="name" }}
</span>
{{/each}}
</div>
{{else}}
No monster selected.
{{/if}}
</script>
To make that work, we need a couple of pieces of magic-magic. This controller is a good start:
App.EditMonsterController = Em.ObjectController.extend({
metadata: function() {
var vals = [];
var attributeMap = this.get('content.constructor.attributes');
attributeMap.forEach(function(name, value) {
vals.push(value);
});
return vals;
}.property('content')
});
That uses that "attributes" property that Ryan mentioned to provide the metadata that we are feeding into our #each up there in the template!
Now, here is a view that we can use to provide the text input. There's an outer container view that is needed to feed the valueBinding in to the actual textfield.
App.AutoTextField = Ember.ContainerView.extend({
type: null,
name: null,
init: function() {
this._super();
this.createChildView();
},
createChildView: function() {
this.set('currentView', Ember.TextField.create({
valueBinding: 'controller.' + this.get('name'),
type: this.get('type')
}));
}.observes('name', 'type')
});
Here is a fiddle demonstrating the whole crazy thing: http://jsfiddle.net/Malkyne/m4bu6/
The Ember Data objects that represent your models have an attributes property that contains all of the attributes for the given model. This is what Ember Data's toJSON uses to convert your models into Javascript objects.
You can use this attributes property to read a models attributes and then pull those specific attributes out of an instance. Here is an example.
http://jsfiddle.net/BdUyU/1/
Just to reiterate what's going on here. We are reading the attributes from App.User and then pulling the values out of App.ryan and App.steve. Hope this makes sense.
Problem Summary: While I can get the children of a collection (defined on an ArrayController) to use a specific object controller for the individuals, this doesn't work on filtered subsets of the children.
Short context: I've got Subcriptions, which have Items. I'd like to filter the subscriptions in my view by type, and have the items within those subscriptions sort by timestamp. Here's the SubscriptionsController:
Social.SubscriptionsController = Ember.ArrayController.extend({
itemController: 'subscription',
announcements: function() {
return this.get('model').filterBy('kind', 'announcement');
}.property('model.#each.kind'),
user_sites: function() {
return this.get('model').filterBy('kind', 'user');
}.property('model.#each.kind')
});
I've defined SubscriptionController thusly:
Social.SubscriptionController = Ember.ObjectController.extend({
items: function() {
return Ember.ArrayProxy.createWithMixins(Ember.SortableMixin, {
sortProperties: ['post_timestamp'],
sortAscending: false,
content: this.get('content.items')
});
}.property('content.items'),
});
And here's the relevant bit of my handlebars template:
{{#each controller}}
<li>{{controller.description}} {{controller.kind}} {{controller.feed_url}} {{controller.base_url}}</li>
<ul>
{{#each item in controller.items}}
<li>{{item.post_timestamp}}: {{{item.summary}}}</li>
{{/each}}
</ul>
{{/each}}
That code more-or-less does what I want: it renders the items, sorted by item.post_timestamp, as SubscriptionController defines it.
The problem is if I change {{#each controller}} to {{#each site in user_sites}}, the itemController property doesn't seem to magically apply to the sublist. Is there some kind of Sorcery I should use to inform Ember in my filters that I'd rather return the controller for the objects rather than the objects themselves?
EDITed to add: I know I can just add a new property like sorted_items on the Subscription model itself, but this feels wrong, design-wise. The model holds the data, the view shows the data, and the controller deals with sorting / filtering and all that jazz. Or at least that's part of how I think about MVC separation.
You can manually set the itemController for loops. You might try this in your template:
{{#each site in user_sites itemController="subscription"}}
...
{{/each}}
I am loading multiple models (using an ArrayController) with ember-data that obviously returns and id for each model and I am displaying some dynamic map content based on that, which is initialized via JS in the didInsertElement function.
So my hbs code looks like this:
{{#each controller}}
....
<div class="map" {{bindAttr id="id"}}>
....
{{/each}}
That works fine, but my problem is, I don't just want the id-number for the div id, but I want it with a static prefix: E.g. user-{{id}}. Or at a different route I would want e.g. news-{{id}}
Is anything like that possible?
Assuming you can store the prefix in you model data, you could create a computed property for this use case:
App.User = DS.Model.extend({
...
prefixedId: function() {
return "user-" + this.get('id');
}.property('id')
});
App.News = DS.Model.extend({
...
prefixedId: function() {
return "news-" + this.get('id');
}.property('id')
});
And then use the computed property instead:
{{#each controller}}
....
<div class="map" {{bindAttr id="prefixedId"}}>
....
{{/each}}
I might be using this all wrong, but:
I've got an ArrayController representing a collection of products. Each product gets rendered and there are several actions a user could take, for example edit the product title or copy the description from a different product.
Question is: how do you interact with the controller for the specific product you're working with? How would the controller know which product was being edited?
I also tried to create an Ember.Select with selectionBinding set to "controller.somevar" but that also failed.
I think the most important thing you need to do, is first move as much logic as you can away from the views, and into controllers.
Another thing that would be useful in your case, is to have an itemController for each product in the list. That way, you can handle item specific logic in this item controller.
I don't have enough information to understand your architecture, so I will make a few assumptions.
Given you have the following ProductsController:
App.ProductsController = Ember.ArrayController.extend();
You need to create a ProductController that will be created to wrap every single product on its own.
App.ProductController = Ember.ObjectController.extend();
You need to modify your template as follows:
{{#each controller itemController="product"}}
<li>name</li>
{{/each}}
Now every product in your list will have its own ProductController, which can handle one product's events and will act as the context for every list item.
Another option:
If you will only be handling one product at a time, you can use routes to describe which product you are working with:
App.Router.map(function() {
this.resource('products', { path: '/products' }, function() {
this.resource('product', { path: '/:product_id' }, function() {
this.route('edit');
});
});
});
And create a controller for editing a product:
App.ProductEditController = Ember.ObjectController.extend();
And your list items would link to that product route:
{{#each controller}}
<li>{{#linkTo "product.edit" this}}name{{/linkTo}}</li>
{{/each}}
If you define itemController on your ProductsController you don't need to specify that detail in your template:
App.ProductsController = Em.ArrayController.extend({
itemController: 'product',
needs: ['suppliers'],
actions: {
add: function() {
// do something to add an item to content collection
}
}
});
App.ProductController = Em.ObjectController.extend({
actions: {
remove: function() {
// do something to remove the item
}
}
});
Use a collection template like this:
<button {{action="add"}}>Add Item</button>
<ul>
{{#each controller}}
<li>{{name}} <button {{action="remove"}}>x</button></li>
{{/each}}
</ul>
The Ember documentation describesitemController here:
You can even define a function lookupItemController which can dynamically decide the item controller (eg based on model type perhaps).
The thing I found when rendering a collection wrapped in an ArrayController within another template/view is the way #each is used. Make sure you use {{#each controller}} as Teddy Zeeny shows otherwise you end up using the content model items and NOT the item controller wrapped items. You may not notice this until you try using actions which are intended to be handled by the item controller or other controller based content decoration.
When I need to nest an entire collection in another view I use the view helper as follows to set the context correctly so that any collection level actions (eg an add item button action) get handled by the array controller and not by the main controller setup by the route.
So in my products template I would do something like this to list the nested suppliers (assuming your route for 'product' has properly the 'suppliers' controller):
{{view controller=controllers.suppliers templateName="products/suppliers"}}
The suppliers template just follows the same pattern as the template I show above.
Is there a way to iterate over a view's context's attributes in EmberJS? I am using Ember-Data (https://github.com/emberjs/data) for ORM.
Lets say I use connectOutlets to register a UserView with a user that has attributes such as email, name, etc. In the connected Handlebars template, is there anyway that I can iterate over those attributes?
I basically need to build a generic view that can be reused with different models...
Ryan is right about the attributes, but it takes some doing to actually get where you're going. My examples here are using the latest RC1 Ember.
Here is an editor template that is model agnostic:
<script type="text/x-handlebars" data-template-name="edit_monster">
{{#if clientId}}
<h1>Edit Monster: {{name}}</h1>
<div>
{{#each metadata}}
<span class="edit-label">{{name}}</span>
<span class="edit-field">
{{view App.AutoTextField typeBinding="type" nameBinding="name" }}
</span>
{{/each}}
</div>
{{else}}
No monster selected.
{{/if}}
</script>
To make that work, we need a couple of pieces of magic-magic. This controller is a good start:
App.EditMonsterController = Em.ObjectController.extend({
metadata: function() {
var vals = [];
var attributeMap = this.get('content.constructor.attributes');
attributeMap.forEach(function(name, value) {
vals.push(value);
});
return vals;
}.property('content')
});
That uses that "attributes" property that Ryan mentioned to provide the metadata that we are feeding into our #each up there in the template!
Now, here is a view that we can use to provide the text input. There's an outer container view that is needed to feed the valueBinding in to the actual textfield.
App.AutoTextField = Ember.ContainerView.extend({
type: null,
name: null,
init: function() {
this._super();
this.createChildView();
},
createChildView: function() {
this.set('currentView', Ember.TextField.create({
valueBinding: 'controller.' + this.get('name'),
type: this.get('type')
}));
}.observes('name', 'type')
});
Here is a fiddle demonstrating the whole crazy thing: http://jsfiddle.net/Malkyne/m4bu6/
The Ember Data objects that represent your models have an attributes property that contains all of the attributes for the given model. This is what Ember Data's toJSON uses to convert your models into Javascript objects.
You can use this attributes property to read a models attributes and then pull those specific attributes out of an instance. Here is an example.
http://jsfiddle.net/BdUyU/1/
Just to reiterate what's going on here. We are reading the attributes from App.User and then pulling the values out of App.ryan and App.steve. Hope this makes sense.