EmberJS: Property Scopes in an ArrayController? - ember.js

this is probably a grossly simple question to answer, so I apologize if I am cluttering this forum in advance.
I am displaying a list of items that share the same model and controller.
I made these items editable via a <button {{ action 'edit' }}> next to each item which toggles a boolean value of a property "isEditable" in the controller.
However clicking this button causes all items in the list to become editable because they all share the controller property "isEditable". The desired effect is to make a single item editable at a time instead of all items at once.
A simplified version of my template looks like this:
{{#if isEditing}}
<p>{{input type="text" value=title}}</p>
<button {{action 'doneEditing'}}>Done</button>
{{else}}
<span class="title">{{title}}</span>
<button {{action 'edit'}}><span class="edit"</span></button>
{{/if}}
and the controller looks like this
App.ItemController = Ember.ArrayController.extend({
isEditing : false,
actions : {
edit : function(){
this.set('isEditing', true);
},
doneEditing : function(){
this.set('isEditing', false);
},
}
});
Anybody know how to accomplish this? Is it because each item shares the "isEditable" property? If so, how do I get around this? I don't want to put this into the model because it's purely a display thing, even though I know I can get it to work doing that.
Thanks :)

By default the controller lookup within an {{#each}} block will be the controller of the template where the {{#each}} was used. If each item needs to be presented by a custom controller (to hold it's own state for example) you can provide a itemController option which references a controller by lookup name. Each item in the loop will be then wrapped in an instance of this controller and the item itself will be set to the content property of that controller.
So, I assume you are displaying the list of items using the {{#each}} helper. Therefore you can specify an itemController in the {{#each}} helper to hold the isEditable state on a per item basis. This would look something like this:
{{#each item in controller itemController="item"}}
...
{{/each}}
Moreover you should define the defined itemController of type Ember.ObjectController like:
App.ItemController = Ember.ObjectController.extend({
isEditing : false,
actions : {
edit : function(){
this.set('isEditing', true);
},
doneEditing : function(){
this.set('isEditing', false);
},
}
});
And for the list you should then have an App.ItemsController of type Ember.ArrayController:
App.ItemsController = Ember.ArrayController.extend({});
See here for more info on the mentioned itemController support for the {{#each}} helper: http://emberjs.com/api/classes/Ember.Handlebars.helpers.html#method_each
Hope it helps.

Related

How to dynamically apply classes to objects in ember-cli?

I'm creating an app that has a listing of items and a series of filter buttons at the top. As the user applies different filters, I want the buttons to change style using CSS classes to show them as enabled/disabled.
I want to be able to write something like the code below, but it doesn't work.
{{#each category in category_options}}
<button {{action "filterCategory" category}} {{bind-attr class=":btn-small isFiltered(category):btn-active:btn-inactive"}}>{{category}}</button>
{{/each}}
In this example, isFiltered is a computed property on the controller, and it looks at the query parameters to determine whether the specified category has been applied as a filter.
From the reading I've done, it sounds like you can't pass parameters to computed properties. I've come across answers mentioning helpers, bound helpers, and components, but I haven't been able to sort out which one I need, or how I would apply it in this situation.
EDIT:
To clarify the example, imagine I have a series of buttons that filter on various tags:
Filter for: <Cats> <Dogs> <Rabbits> ... # imagine an arbitrary number of these. dozens, maybe
When a user clicks Cats, it triggers filterCategory, which sets the model.category query parameter to ['Cats']. If he then clicks Dogs, model.category becomes ['Cats','Dogs']
Following the latter case, I want the Cats and Dogs buttons to have the class btn-active.
I would like to define isFiltered like so:
isFiltered: function(buttonname) {
if (this.get('model.categories').containsObject(buttonname)) { # pseudocode
return true;
}
else { return false; }
}
Passing buttonname into the function makes it easy to do the comparison for every button and determine if it's in the filter.
If this overall approach is the wrong way to go about things, what's the right way to do it?
1)As component you can do something like below:
in template
{{#each category in category_options}}
{{category-button category=category selectedCategoies=selectedCategories action="filterCategory"}}
{{/each}}
component template
{{category}}
component
export default Ember.Component.extend({
tagName: 'button',
classNames: 'btn-small',
classNameBindings: 'isFiltered:btn-active:btn-inactive',
isFiltered: Ember.computed('category', 'selectedCategories', function(){
return this.get('selectedCategories').contains(this.get('category'));
}),
click: function(){
this.sendAction('action', this.get('category'));
}
})
2)Or you can make your categories as array of objects like so
[
{name: 'category1', isActive: false},
{name: 'category2', isActive: true},
...
]
And then change isActive flag as you need.
In controller:
categoryObjects: Ember.computed('category_options', function(){
return this.get('category_options').map(function(category){
Ember.Object.create({name: category, isActive: false});
})
}),
actions: {
filterCategory: function(category){
category.toggleProperty('isActive');
return
}
}
And in template:
{{#each category in categoryObjects}}
<button {{action "filterCategory" category}} {{bind-attr class=":btn-small category.isActive:btn-active:btn-inactive"}}>{{category.name}}</button>
{{/each}}
I'm not sure how the rest of your code looks like but in general you would use model hook in your route to get query parameter, process it, if needed, and return with your model, let's say you would return model.category, then in your controller you would have something like this:
isFiltered: function() {
var category = this.get('model.category');
// do whatever you want here with category to return true or false
}.property('model.category')
then in .hbs you would be able to write this:
{{#each category in category_options}}
<button {{action "filterCategory" category}} {{bind-attr class=":btn-small isFiltered:btn-active:btn-inactive"}}>{{category}}</button>
{{/each}}
If you were to do this by your approach, you can get it working by making a Computed Property Macro and then looping over the category_options and creating computed properties as isCategory ( isRed, isBlue etc..)
But this won't be the right way to do it, You need to make those button components, which will accept the category_options and model.category and internally decide whether it should be active or not.

ArrayController's property for each item in the model in ember

I've an Array controller which has the property "isChecked" (boolean property). In my controller I want to get the collection of elements which are "checked" (I mean selected). I'm not sure how to access the controller's property in the model.
My controller is as follows:
App.ExampleController = Ember.ArrayController.extend({
isChecked: false,
totalElements: function()
{
return this.model.get('length');
}.property('#each'),
selectedElements: function()
{
var content = this.get('content');
console.log(content.filterBy('isChecked'));
return content.filterBy('isChecked');
}.property('isChecked'),
});
I linked the "isChecked" property to a checkbox inside each helper as follows..
<ul>
{{#each model}}
<li>
{{input type="checkbox" checked=isChecked}}
{{name}}
</li>
{{/each}}
</ul>
I will display all the items in the model with a checkbox associated with it. The user can select few items from it. So I want those items.
Now I want to get the list of elements which are "checked". Either as a computed property or under any action.
Thank you.
I think you need to move the isChecked property onto an ObjectController, then reference that controller in the array controller with the itemController property.
Array Controller:
App.IndexController = Ember.ArrayController.extend({
itemController: 'color',
totalElements: function() {
return this.get('length');
}.property('[]'),
selectedElements: Ember.computed.filterBy('#this', 'isChecked', true)
});
(The #this means that the computed property will reference the array of item controllers.)
Item Controller:
App.ColorController = Ember.ObjectController.extend({
isChecked: false
});
http://emberjs.jsbin.com/tazojejuwi/1/edit
Hope that helps.

getting back reference to a specific model using Ember's Array Controller

I'm new to Ember and am finding some of their concepts a bit opaque. I have a app that manages inventory for a company. There is a screen that lists the entirety of their inventory and allows them to edit each inventory item. The text fields are disabled by default and I want to have an 'edit item' button that will set disabled / true to disabled / false. I have created the following which renders out correctly:
Inv.InventoryitemsRoute = Ember.Route.extend({
model: function(params) {
return Ember.$.getJSON("/arc/v1/api/inventory_items/" + params.location_id);
}
<script type="text/x-handlebars" data-template-name="inventoryitems">
{{#each}}
<div class='row'>
<p>{{input type="text" value=header disabled="true"}}</p>
<p>{{input type="text" value=detail disabled="true"}}</p>
<button {{action "editInventoryItem" data-id=id}}>edit item</button>
<button {{action "saveInventoryItem" data-id=id}}>save item</button>
</div>
{{/each}}
</script>
So this renders in the UI fine but I am not sure how to access the specific model to change the text input from disabled/true to disabled/false. If I were just doing this as normal jQuery, I would add the id value of that specific model and place an id in the text input so that I could set the textfield. Based upon reading through docs, it seems like I would want a controller - would I want an ArrayController for this model instance or could Ember figure that out on its own?
I'm thinking I want to do something like the following but alerting the id give me undefined:
Inv.InventoryitemsController=Ember.ArrayController.extend({
isEditing: false,
actions: {
editInventoryItem: function(){
var model = this.get('model');
/*
^^^^
should this be a reference to that specific instance of a single model or the list of models provided by the InventoryitemsRoute
*/
alert('you want to edit this:' + model.id); // <-undefined
}
}
});
In the Ember docs, they use a playlist example (here: http://emberjs.com/guides/controllers/representing-multiple-models-with-arraycontroller/) like this:
App.SongsRoute = Ember.Route.extend({
setupController: function(controller, playlist) {
controller.set('model', playlist.get('songs'));
}
});
But this example is a bit confusing (for a couple of reasons) but in this particular case - how would I map their concept of playlist to me trying to edit a single inventory item?
<script type="text/x-handlebars" data-template-name="inventoryitems">
{{#each}}
<div class='row'>
<p>{{input type="text" value=header disabled="true"}}</p>
<p>{{input type="text" value=detail disabled="true"}}</p>
<button {{action "editInventoryItem" this}}>edit item</button>
<button {{action "saveInventoryItem" this}}>save item</button>
</div>
{{/each}}
</script>
and
actions: {
editInventoryItem: function(object){
alert('you want to edit this:' + object.id);
}
}
Is what you need. But let me explain in a bit more detail:
First of all, terminology: Your "model" is the entire object tied to your controller. When you call this.get('model') on an action within an array controller, you will receive the entire model, in this case an array of inventory items.
The {{#each}} handlebars tag iterates through a selected array (by default it uses your entire model as the selected array). While within the {{#each}} block helper, you can reference the specific object you are currently on by saying this. You could also name the iteration object instead of relying on a this declaration by typing {{#each thing in model}}, within which each object would be referenced as thing.
Lastly, your actions are capable of taking inputs. You can declare these inputs simply by giving the variable name after the action name. Above, I demonstrated this with {{action "saveInventoryItem" this}} which will pass this to the action saveInventoryItem. You also need to add an input parameter to that action in order for it to be accepted.
Ok, that's because as you said, you're just starting with Ember. I would probably do this:
<script type="text/x-handlebars" data-template-name="inventoryitems">
{{#each}}
<div class='row'>
<p>{{input type="text" value=header disabled=headerEnabled}}</p>
<p>{{input type="text" value=detail disabled=detailEnabled}}</p>
<button {{action "editInventoryItem"}}>edit item</button>
<button {{action "saveInventoryItem"}}>save item</button>
</div>
{{/each}}
</script>
with this, you need to define a headerEnabled property in the InventoryitemController(Note that it is singular, not the one that contains all the items), and the same for detailEnabled, and the actions, you can define them also either in the same controller or in the route:
App.InventoryitemController = Ember.ObjectController.extend({
headerEnabled: false,
detailEnabled: false,
actions: {
editInventoryItem: function() {
this.set('headerEnabled', true);
this.set('detailEnabled', true);
}
}
});
that's just an example how you can access the data, in case the same property will enable both text fields, then you only need one, instead of the two that I put . In case the 'each' loop doesn't pick up the right controller, just specify itemController.

Bind Checkbox Settings to Array Content in EmberJS

I have a group of checkboxes in an EmberJS app. I would like to maintain a property in the controller that corresponds to the checked boxes (e.g. contains a string entry with the id of each box that is checked). This property should update itself as boxes are checked or unchecked. What is the best way to do this?
Computed property would do
F.e.
App.MyController = Em.ObjectController.extend({
checkboxValues : [Em.Object.create({id:1, check:false}), Em.Object.create({id:2, check:true})],
checkedIds : function() {
return this.get('checkboxValues').filterBy('check').mapBy('id').join(',');
}.property('checkboxValues.#each.check')
});
//template
{{#each checkboxValues}}
{{id}} {{input type="checkbox" name="checkbox" checkedBinding="check"}}
{{/each}}
{{checkedIds}}

dynamic outlet name in ember js

Requirement: There will be few buttons, and on clicking every button the immediate outlet will be rendered with a view. (not the other outlets present in the page)
Suppose I'm creating outlets in #each.
{{#each item in model}}
<#link-to 'passenger' item.id>Open Corresponding Outlet </link-to>
{{outlet item.id}}
{{/each}}
and from back i'm rendering the outlet:
model: function (params) {
return [
{ id: params.passenger_id}
]
},
renderTemplate: function () {
this.render({ outlet: this.get('controller.model')[0].id });
},
This just doesn't work.
Can anyone help me to do that?
You can't create dynamic named outlets, and it would break the url representing the page you are viewing concept which the core members preach heavily.
You should just render in the template using the render helper, and use
{{#each item in model}}
{{render 'something' item}}
{{/each}}
And inside the something controller/template you can add additional logic for how you'd like it to interact.
Additionally you could just add another resource under your passenger route and ad an outlet which hosts that information when it's clicked.
Not sure if you're still looking for a solution, as #kinpin2k mentioned you can't use dynamic outlets, but perhaps a dynamic partial would help.
Like so:
{{partial someTemplateName}}
Where someTemplateName can be any computed property in your controller. If the property returns falsy then nothing will be displayed.
Here's the reference: http://emberjs.com/api/classes/Ember.Handlebars.helpers.html#toc_bound-template-names