[BUGFIX release] Deprecate @each as a leaf node.

[rwjblue]

Update stable version with a deprecation when using foo.@each as a dependent key. This code is removed on beta (2.0.0) and canary (2.1.0) branches already.

[rauhryan]

@rwjblue just out of curiousity.

Is it still possible to track a sub-property of things in the array that are one level deep.

I assume what used to be

Ember.computed('[email protected]')

is changed to

Ember.computed('foos.[].bar')

and all is well?

[stefanpenner]

@rauhryan other way around:

Ember.computed('foos.[].bar') should be Ember.computed('[email protected]')
Ember.computed('foos.@each') should be Ember.computed('foos.[]')

@each is for chaining
[] is to describe array mutations on the leaf IFF it is an arraylike

[rauhryan]

thanks for clarification @stefanpenner

I'll pass it on to the team

[icecoldmax]

@stefanpenner How about observing ANY property changes on things like ObjectProxys? I've been doing Ember.observer("foos.@each") to catch any change (say the checked property for a checkbox). Will this still work with Ember.observer("foos.[]")?

[stefanpenner]

@icecoldmax I don't believe that is a feature. @each and [] are for arrays and array proxies. Not objects or object proxies.

I'm dubious that this works as you describe.

[icecoldmax]

@stefanpenner I think I described it wrong.

Let me try my checkbox example better:

proxiedFoos: Ember.computed("foos", function() {
  return this.get("foos")
    .map((foo) => {
      return Ember.ObjectProxy.create({
        content: foo,
        checked: false,
      });
  });
})

Let's say these are now iterated over as a list of checkboxes where checking it updates the checked to true. We want to do something when any of them are checked, so we've been successfully using Ember.observer("proxiedFoos.@each").

Is this bad practice?

[stefanpenner]

Ember.observer("proxiedFoos.@each").

since there is a map, proxiedFoos is always an array and the following should be true.

• proxiedFoos.@each becomes proxiedFoos.[]
• but [email protected] is used for chaining, and thus stays the same.

[aortbals]

I found that the easiest way to compare these various computed properties was live. I was slightly confused about the behavior. Here is a twiddle: http://ember-twiddle.com/02ddca9b6c89f2f8f92b.

TLDR, from my understanding:

• array.[] is for observing the array itself, such as adding or removing items and is supported in 2.0
• [email protected] will recomputed if any of the items name prop is updated and is supported in 2.0
• array.@each is deprecated, and it does not observe all item attributes (I think this is what some users expect) in 1.12 or 1.13. It works identically to array.[] in 1.13 from my testing
• You should use array.[] or [email protected] only

[icecoldmax]

@stefanpenner @aortbals Thanks for the clarification.

Is there actually a way to do what I'm thinking of? Say you have an array of objects, each with a ton of attributes and you want to observe when any of their properties change. Any way other than just observing/computing on @each.propName?

[stefanpenner]

@each.propName?

no – only granular changes are currently supported.