item-specific actions in ember.js collection views - ember.js

I'm just starting to play around with the ember.js library to see what it's all about. I want to display a table of data, and to the right of each row, have a delete button to delete that item from the table. I have no idea how to do this though.
Note, I also tried to create a child view (ItemView) and use it inline within the {{#each ...}}...{{/each}} section, but ember.js complains about expecting a view class instead of ItemView, even though ItemView is defined using Ember.View.create. I would also like to know why that isn't working. Even the sample code for using a child view in an #each block in the documentation doesn't work.
Even if I could declare a child view called ItemView to render each individual Item, I still wouldn't know how to get that particular view's removeItem action to know which item to remove from the itemsController collection. Is there a property of the View to get back the Item instance that the child view is bound to in a collection?
Here is the part of my view template that has the list:
{{#each App.itemsController}}
<tr>
<td>{{itemName}}</td>
<td><a href="#" {{action "removeItem" on="click"}}>Delete</a></td>
</tr>
{{/each}}
And here is my javascript:
window.App = Ember.Application.create();
window.App.Item = Ember.Object.extend({
itemName: "defaultItemName"
});
window.App.itemsController = Ember.ArrayProxy.create({
content: []
});
window.App.ListView = Ember.View.create({
templateName: 'listView',
removeItem: function (event) {
// ??? How do I figure out what item
// the user wanted to remove?
}
});

Yehuda's post Michael linked to demonstrates the correct approach, using a child ItemView inside the each. Not sure why that didn't work for you, you've removed that bit of code from your question unfortunately.
Some of the syntax in Yehuda's answer is slightly out of date so I've updated it and changed it to be a bit more like your question. You can check it out here: http://jsfiddle.net/wmarbut/67GQb/130/ (updated link to jsfiddle 1/21/12)
The thrust of it is
Handlebars
{{#each App.peopleController}}
{{#view App.PersonView personBinding="this"}}
<td>{{view.person.fullName}}</td>
<td><button {{action removeItem target="view"}}>Delete</button>
{{/view}}
{{/each}}
Javascript
App.PersonView = Ember.View.extend({
tagName: 'tr',
person: null,
removeItem: function() {
var person = this.get('person');
App.peopleController.removeObject(person);
}
});

Thanks to Tom Whatmore fiddle I found answer to the same question.
After reading trek intro, instead of personBinding="this", I'd rather use {{action removeItem person}} to explicitly indicate object on which action should be performed.
<script type="text/x-handlebars">
<table>
{{#each person in App.peopleController}}
{{#view App.PersonView}}
<td>{{person.fullName}}</td>
<td><button {{action removeItem person}}>Delete</button>
{{/view}}
{{/each}}
</table>
</script>
In the view I'd use var person = evt.context; to get person object.
App = Ember.Application.create();
App.Person = Ember.Object.extend({
fullName: function() {
return this.get('firstName') + ' ' + this.get('lastName');
}.property('firstName', 'lastName')
});
App.peopleController = Ember.ArrayProxy.create({
content: [App.Person.create({ firstName: "Yehuda", lastName: "Katz" }),
App.Person.create({ firstName: "Tom", lastName: "Dale" })]
});
App.PersonView = Ember.View.extend({
tagName: 'tr',
removeItem: function(evt) {
var person = evt.context;
App.peopleController.removeObject(person);
}
});
You can play with this fiddle jsfiddle.net/67GQb/127

Not sure if this the best way but I've put the item index or item name as a property of the tag and then use jQuery to fetch it.
// template
{{#each App.itemsController}}
<tr itemName="{{itemName}}">
<td>{{itemName}}</td>
<td><a href="#" {{action "removeItem" on="click"}}>Delete</a></td>
</tr>
{{/each}}
// Javascript
window.App.ListView = Ember.View.create({
templateName: 'listView',
removeItem: function (event) {
var id = this.$().parent().parent().attr('itemName');
...
}
});
Hope this helps.

Related

Ember.js: replacing simple linkTo helper with a view

I've got an app with basic functionality built out. I'm not going through and adding additional features. In this case I need to convert a simple button, currently using linkTo, to a View. Problem is that I'm not sure how to convert one to the other and still keep the link intact.
How do I do this conversion? Here's the code I have now:
<script type="text/x-handlebars" data-template-name="accountItem">
{{#each account in controller}}
{{#linkTo "account" account}}
<img {{bindAttr src="account.icon"}} />
{{/linkTo}}
{{/each}}
</script>
and here's the code I'm going to have:
<script type="text/x-handlebars" data-template-name="accountItem">
{{#each account in controller}}
{{#view "Social.AccountButtonView"}}
<img {{bindAttr src="account.icon"}} />
{{/view}}
{{/each}}
</script>
Social.AccountButtonView = Ember.View.extend({
tagName: 'a',
classNames: ['item-account'],
click: function(){
// do something
}
});
I would assume that I'd be building on top of the click handler in the View, but I'm not sure how to pass the reference to item being iterated over, nor how to reference the correct route within the View.
Assistance please?
Update 1
The first version renders an href attribute with a value of #/accounts/4 based on the Router I have set up:
Social.Router.map(function() {
this.resource('accounts', function(){
this.resource('account', { path: ':account_id'});
});
});
When I convert the current code to a view, how do I mimic the functionality that linkTo provides?
You can define a property binding for account in your handlebars template.
This binding works like this:
<script type="text/x-handlebars">
<h1>App</h1>
{{#each item in controller}}
{{#view App.AccountView accountBinding="item"}}
<a {{bindAttr href="view.account.url"}} target="_blank">
{{view.account.name}}
</a>
{{/view}}
{{/each}}
</script>
Note that I added accountBinding, so the general rule is propertyName and Binding as a suffix. And remember that when you add a property to a view, you will not be able to access it directly, instead you will have to access it with view.propertyName as shown above.
Just keep in mind that you must have a View class when using the {{view}} helper:
window.App = Em.Application.create();
App.AccountView = Em.View.extend(); // this must exist
App.ApplicationRoute = Em.Route.extend({
model: function() {
return [
{id: 1, name: 'Ember.js', url: 'http://emberjs.com'},
{id: 2, name: 'Toronto Ember.js', url: 'http://torontoemberjs.com'},
{id: 3, name: 'JS Fiddle', url: 'http://jsfiddle.com'}];
}
})
Working fiddle: http://jsfiddle.net/schawaska/PFxHx/
In Response to Update 1:
I found myself in a similar scenario, and ended up creating a child view to mimic the {{linkTo}} helper. I don't really know/think it's the best implementation tho.
You can see my previous code here: http://jsfiddle.net/schawaska/SqhJB/
At that time I had created a child view within the ApplicationView:
App.ApplicationView = Em.View.extend({
templateName: 'application',
NavbarView: Em.View.extend({
init: function() {
this._super();
this.set('controller', this.get('parentView.controller').controllerFor('navbar'))
},
selectedRouteName: 'home',
gotoRoute: function(e) {
this.set('selectedRouteName', e.routeName);
this.get('controller.target.router').transitionTo(e.routePath);
},
templateName: 'navbar',
MenuItemView: Em.View.extend({
templateName:'menu-item',
tagName: 'li',
classNameBindings: 'IsActive:active'.w(),
IsActive: function() {
return this.get('item.routeName') === this.get('parentView.selectedRouteName');
}.property('item', 'parentView.selectedRouteName')
})
})
});
and my Handlebars looks like this:
<script type="text/x-handlebars" data-template-name="menu-item">
<a {{action gotoRoute item on="click" target="view.parentView"}}>
{{item.displayText}}
</a>
</script>
<script type="text/x-handlebars" data-template-name="navbar">
<ul class="left">
{{#each item in controller}}
{{view view.MenuItemView itemBinding="item"}}
{{/each}}
</ul>
</script>
I'm sorry I can't give you a better answer. This is what I could come up with at the time and haven't touched it ever since. Like I said, I don't think this is the way to handle it. If you are willing to take a look into the {{linkTo}} helper source code, you'll see a modular and elegant implementation that could be the base of your own implementation. I guess the part you're looking for is the href property which is being defined like so:
var LinkView = Em.View.extend({
...
attributeBindings: ['href', 'title'],
...
href: Ember.computed(function() {
var router = this.get('router');
return router.generate.apply(router, args(this, router));
})
...
});
So I guess, from there you can understand how it works and implement something on your own. Let me know if that helps.

How to render a stream view like in twitter of facebook with emberjs arraycontroller?

To render a content of an array with emberjs we usually do the following
<ul>
{{#each controller}}
<li>{{name}} by {{artist}}</li>
{{/each}}
</ul>
How to make a live stream view like we have with twitter (of facebook) where a new stream is added on the top of the streams list ?
On the controller you can set the sortProperties see here to specify on which property the array should be sorted and you can set sortAscending (which is a boolean) to specify which direction the array should be sorted.
When you change the array the view will automatically update.
see this fiddle: http://jsfiddle.net/ZnMFK/2/
or this fiddle: http://jsfiddle.net/KfzFE/ to show the DOM gets updated when the array is changed.
HTML:
<script type="text/x-handlebars" data-template-name="index">
<div class="patient-view extended">
{{#each controller}}
<p>Name: {{name}}</p>
{{/each}}
</div>
</script>
App:
window.App = Em.Application.create();
App.Patient = Em.Object.extend({
order: undefined,
name: undefined
});
App.IndexView = Em.View.extend({
click: function() {
this.get('controller')
.set('sortAscending', !this.get('controller').get('sortAscending'));
}
});
App.IndexController = Em.ArrayController.extend({
sortProperties: ['order'],
sortAscending: false
});
App.IndexRoute = Em.Route.extend({
model: function() {
return Em.A([App.Patient.create({
name: "Bert",
order: 2
}), App.Patient.create({
name: "Ernie",
order: 1
})]);
}
});

How to pass events to a parent View, passing the child View that triggered the event?

Consider a View that defines a list of objects:
App.ListView = Ember.View({
items: 'App.FooController.content'
itemClicked: function(item){
}
)};
with the template:
<ul>
{{#each items}}
{{#view App.ItemView itemBinding="this" tagName="li"}}
<!-- ... -->
{{/view}}
{{/each}}
</ul>
and the ItemView:
App.ItemView = Ember.View.extend({
click: function(event){
var item = this.get('item');
// I want to call function itemClicked(item) of parentView
// so that it handles the click event
}
})
So basically my question is how do I pass events to parent views, especially in the case where the parent view is not known by the child view? I understand that you can get a property foo of a parentView with either this.getPath('parentView').get('foo') or this.getPath('contentView').get('foo'). But what about a function (in this case, itemclicked())?
this.get('parentView').itemClicked(this.get('item')); should do the trick.
You can use the {{action}} helper, see: http://jsfiddle.net/smvv5/
Template:
<script type="text/x-handlebars" >
{{#view App.ListsView}}
{{#each items}}
{{#view App.ListView itemBinding="this" }}
<li {{action "clicked" target="parentView" }} >{{item.text}}</li>
{{/view}}
{{/each}}
{{/view}}
</script>​
JS:
App = Ember.Application.create({});
App.Foo = Ember.ArrayProxy.create({
content: [Ember.Object.create({
text: 'hello'
}), Ember.Object.create({
text: 'action'
}), Ember.Object.create({
text: 'world'
})]
});
App.ListsView = Ember.View.extend({
itemsBinding: 'App.Foo',
clicked: function(view, event, ctx) {
console.log(Ember.getPath(ctx, 'item.text'));
}
});
App.ListView = Ember.View.extend({
});​
Recent versions of Ember use the actions hash instead of methods directly on the object (though this deprecated method is still supported, it might not be for long). If you want a reference to the view passed to the handler, send through "view" as a parameter and use the parentView as the target.
<button {{action "onClicked" view target="view.parentView"}}>Click me.</button>
App.ListsView = Ember.View.extend({
actions: {
onClicked: function(view) {
}
}
});
{{action}} helper does not send through the event object. Still not sure how to get reference to the event if you need it.
source

Binding value from textfield when pressing button

I have the following example (see below) to work with Ember.js, and everything works alright as far as I enter something in the textfield and press enter. But how can I have the same result when I press the button? How can I bind the value of the textfield when clicking the button? Do I have work with a view?
Thanks in advance!
<script type="text/x-handlebars">
{{view App.TextField}}
{{#view Ember.Button target="App.peopleController" action="addPerson"}}
Add Person
{{/view}}
<ul id='todo-list'>
{{#each App.peopleController }}
<li>{{name}}</li>
{{/each}}
</ul>
</script>
<script>
App = Em.Application.create();
App.peopleController = Em.ArrayController.create({
content: [{name: "Tom"}, {name: "Mike"}],
addPerson: function(name) {
this.unshiftObject(App.Person.create({name: name}));
}
});
App.Person = Em.Object.extend({
name: null
});
App.TextField = Em.TextField.extend({
insertNewline: function() {
App.peopleController.addPerson(this.get("value"));
this.set("value", "");
}
});
</script>
This is actually a little tricky to accomplish, but I've reworked your example in a jsFiddle: http://jsfiddle.net/ebryn/vdmrA/
I would advise against hardcoding references to controllers in your view subclasses. You can't reuse those view components elsewhere if you do that.
I think in your code for the Ember Button is just going to call the addPerson function without giving it the name parameter that it expects. You might have to write a separate view for that button in order to get the value of the input field to pass to the addPerson function.
App.MyButton = Em.Button.extend({
click: function(){
var value = App.TextField.get('value')
// etc
}

select dropdown with ember

I'm trying to produce a select input and pass the selected object to the change event on the view. The ember contact example uses a <ul> but with a select the view needs to be outside the each otherwise the change even isn't fired.
Here is the view js:
App.SelectView = Ember.View.extend({
change: function(e) {
//event for select
var content = this.get('content');
console.log(content);
App.selectedWidgetController.set('content', [content]);
},
click: function(e) {
//event for ul
var content = this.get('content');
console.log(content);
App.selectedWidgetController.set('content', [content]);
}
});
The ul from the example works:
<ul>
{{#each App.widgetController.content}}
{{#view App.SelectView contentBinding="this"}}
<li>{{content.name}}</li>
{{/view}}
{{/each}}
</ul>
But if I replace html directly, the change event isn't fired (which makes sense)
<select>
{{#each App.widgetController.content}}
{{#view App.SelectView contentBinding="this"}}
<option>{{content.name}}</option>
{{/view}}
{{/each}}
</select>
So I guess the select has to be wrapped in the view.. in which case how do I pass the relevant object?... This code results in the entire array being passed:
{{#view App.select_view contentBinding="App.widgetController.content"}}
<select>
{{#each App.widgetController.content}}
<option>{{name}}</option>
{{/each}}
</select>
{{/view}}
Ember now has a built-in Select view.
Here's a usage example:
var App = Ember.Application.create();
App.Person = Ember.Object.extend({
id: null,
firstName: null,
lastName: null,
fullName: function() {
return this.get('firstName') + " " + this.get('lastName');
}.property('firstName', 'lastName').cacheable()
});
App.selectedPersonController = Ember.Object.create({
person: null
});
App.peopleController = Ember.ArrayController.create({
content: [
App.Person.create({id: 1, firstName: 'Yehuda', lastName: 'Katz'}),
App.Person.create({id: 2, firstName: 'Tom', lastName: 'Dale'}),
App.Person.create({id: 3, firstName: 'Peter', lastName: 'Wagenet'}),
App.Person.create({id: 4, firstName: 'Erik', lastName: 'Bryn'})
]
});
Your template would look like:
{{view Ember.Select
contentBinding="App.peopleController"
selectionBinding="App.selectedPersonController.person"
optionLabelPath="content.fullName"
optionValuePath="content.id"}}
Again, here's a jsFiddle example: http://jsfiddle.net/ebryn/zgLCr/
check out the answers to a similar question: How to bind value form input select to attribute in controller
In the examples a CollectionView is used with an tagName=select. You may find this helpful in getting it work.
EDIT: Since I was looking to implement a select myself, here is the solution I came up with:
views/form.js.hjs:
{{#view contentBinding="App.typeController" valueBinding="type" tagName="select"}}
{{#each content}}
<option {{bindAttr value="title"}}>{{title}}</option>
{{/each}}
{{/view}}
{{#view Ember.Button target="parentView" action="submitEntry"}}Save{{/view}}
The select is part of a form. I do check for the submit event and in there read the value:
app.js.coffee
# provides the select, add value: 'my_id' if you need differentiation
# between display name (title) and value
app.typeController = Ember.ArrayProxy.create
content: [{title:'Energy'}, {title:'Gas'}, {title:'Water'}]
# simplified version, but should prove the point
app.form_view = Ember.View.create
templateName: 'views_form'
type: null
submitEntry: () ->
console.log this.$().find(":selected").val()
Hope this helps.
This isn't an Answer, just a fix on the broken jsfiddle link.. Apparently jsfiddle has no love for ember :/ But JsBin does! http://jsbin.com/kuguf/1/edit