Interpolating variables when passing arguments to a view - ember.js

I'm trying to render a bunch of dynamic <select> boxes, supplied by a model. The user is supposed to fill these out, after which the data is saved. Currently I'm looping over the availableParameters object and rendering an Ember.Select view for each of the pairs in the object. This works alright. However, I'm having trouble setting up the valueBinding in such a way that I can retrieve the values in the controller, because I can't seem to interpolate the label variable in the passed argument to the view.
{{#each availableParameters}}
{{label}}
{{view Ember.Select
contentBinding="values"
valueBinding="controller.param.[label]"
}}
{{/each}}
The availableParameters object looks like this:
[
{
label: "label1",
values: [
"value1",
"value2",
"value3"
]
},
...
]
Is there a way to dynamically set the value of the valueBinding to controller.param.[label1] (using the array of objects above) or is there a better way of achieving what I'm looking for?

No, you need to do:
selectedValue: function() {
this.get('values')[this.get('label')]
}.property('values.[]', 'label')
This property can be on the itemController for the {{#each}} helper if you need it to be (an itemController is a good way to approach this problem)

Related

Ember.js: Is it possible to have a component for each field in a model?

So I thought I had this solved already as it worked with my prototype using just arrays, but now that I'm actually dealing with the model, I'm not sure if it will work.
If I create a property on my controller like so:
myAttributes: [{
name: 'attr1',
label: 'Attribute 1',
value: null
}, {
name: 'attr2',
label: 'Attribute 2',
value: 1
}]
then I can loop through myAttributes with {{#each}}, so while each object is essentially a field, that's different than the fields on a single model, which only have a value, so I can't do {{#each model as |rec|}} when there's only one record.
In a nutshell, I want to have a button group to set the value for each field in my model, like so:
I have around 60 of these fields so that's why I wanted to use {{#each}} and my component for each field, but of course each goes over records in the model, not fields in a record.
Is this impossible to do? Do I just have to bite the bullet and write out the markup for each field like I would do if I had only a few fields?
Update: Even if I could loop through the fields on a single record (maybe with {{#each model.#each as |field|}}?), for this case what I also need to do is break out the fields into sections in the UI, so for example loop through fields 1-10 in the first section, and 11-20 in the next section, and there doesn't seem to be a good way to do that.
In the end, I think I'm better off just using a component on each field, like so:
{{attribute-component value=model.attr1}}
{{attribute-component value=model.attr2}}
.
.
.
There's a neat helper called each-in that iterates over key/attributes of an object.
https://guides.emberjs.com/v2.6.0/templates/displaying-the-keys-in-an-object/
There is a way to do that in your case, but I think that actually a simpler way to get the same effect is this:
template.hbs
{{#each myArrayOfPeople as | person | }}
{{#each attribs as | anAttrib | }}
{{get person (mut anAttrib)}},
{{/each}}
<br>
{{/each}}
component.js
attribKeys:['name', 'phoneNumber', 'otherAttrib'];
This will output something like:
joe, 123, something,
sam, 456, anotherthing,
sarah, 944, foo
you can use that same (mut anAttrib) helper to bind an attribute to an input or whatever your need is.
{{attribute-component value=(mut anAttrib)}}
I have now forgone trying to iterate over each field because I actually need to break out the fields into accordion containers based on other criteria, although #averydev's answer about nested {{#each}} was a very cool tip and useful.
I also updated to Ember 1.13 in order to use the mut helper (although I had previously used an action on the component, that passes the new value to an action in the controller, that sets the value to the model property. Since that was convoluted, this new method using mut is much more understandable.
Just to help anyone else out in the future, here's my code (simplified for SO, the real code has nothing to do with rooms and furniture). I have a custom component that uses a radio button group component to actually set the value (this is from ember-radio-button):
template.hbs
{{room-style title='Living Room' field=(mut model.livingRoomStyle)}}
{{room-style title='Master Bedroom' field=(mut model.masterStyle)}}
templates/components/room-style.hbs
<div class="btn-group" data-toggle="buttons">
{{#radio-button value=1 groupValue=field classNames="btn btn-default" changed="changed"}}
Modern
{{/radio-button}}
{{#radio-button value=2 groupValue=field classNames="btn btn-default" changed="changed"}}
French
{{/radio-button}}
{{#radio-button value=3 groupValue=field classNames="btn btn-default" changed="changed"}}
Rustic
{{/radio-button}}
</div>
components/room-style.js
import Ember from 'ember';
export default Ember.Component.extend({
actions: {
changed: function() {
//update() is a function you get with attrs.[prop] when using the mut helper
this.attrs.field.update(this.get('field'));
}
}
});

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.

EmberJS - change how an object property is displayed (not tied to route's controller)

Within my Ember app, I have an object model, called Item, with a property 'price', which holds a float value, such as 20.5. When I use the property in a template {{price}}, I would like for it to be formatted to look like so: $20.50.
This object is not the model that is tied to the controller at the route, but rather an element in an Ember Array, called items, which is a property of the model at the route. So I have something like this in my template:
{{#each item in items}}
{{item.price}}
{{/each}}
The problem seems pretty simple, but I can't really find a solution. The idea is that I do not want to change the name of the property to get it to look the way I want, since I could make a computed property that formats the price property, but then I would have to use a new name in the templates.
What you could do is write your own custom handlebars helper.
For your use case it would look something like this:
Ember.Handlebars.registerBoundHelper('formatNumber', function(value) {
return "$" + value.toFixed(2);
});
And then use it in your templates this way:
{{#each item in items}}
{{formatNumber item.price}}
{{/each}}
Please see here for a working jsbin.
Hope it helps.

How to display specific item from array in Ember.js's template?

Is there any way to do something like that in Ember.js template?
{{someObject.someArray[0].arrayPropery}}
When object structure looks like this:
someObject: {
someArray: [
{
arrayProperty: 'Show me in template!'
}
]
}
You could use: {{ someObject.someArray.firstObject.property }} but it's better to provide a computed property in your controller which returns the desired property.

ember.js #each order by property

I have an array of Ember.Objects which is displayed by Handlebars {{#each}} helper which I want to be sorted by an property of those objects everytime the array changes.
So something like this:
var arr = [
Ember.Objects.create({
position:0,
label:"foo"
}),
Ember.Objects.create({
position:1,
label:"bar"
}),
];
And the handlebar
{{#each arr}}
<div class="label">{{label}}</div>
{{/each}}
So if I update the positions and the bar object becomes first, I want the view to be updated. Can I depend the {{#each}} Helper on an property?
You have to use an ArrayController proxy on your data, and set the sortProperties attribute. Then, use the controller as the each data source.
Sample # http://jsfiddle.net/MikeAski/Epjqp/
Using the controller as the data source provides an arranged content. Take care not to use directly the controller's content, as it is the raw source data...