add more computed macros

[tchak]

• empty
• notEmpty
• not
• bool
• match
• equal
• gt
• gte
• lt
• lte

[tchak]

@stefanpenner let me know if you think some are useless and if some are missing. I will add tests once we decided on the list of macros to add.

[stefanpenner]

@tchak ember recent changed its empty -> isEmpty should the macro follow this pattern?

[tchak]

@stefanpenner I would prefer not to...

[stefanpenner]

we already have: not empty bool

we may want or and any
or: returns the first truthy value
any: returns true if any value is truth, else false

[stefanpenner]

and would be useful

[tchak]

or any and should take an arbitrary number of keys ?

[stefanpenner]

yup

[stefanpenner]

Em.computed.and = (dependentKeys)->
  dependentKeys = Ember.makeArray(dependentKeys)

  computed = (->
    properties = @getProperties.apply(@, dependentKeys)

    for name, value of properties
      return false unless value

    true
  )

  computed.property.apply(computed, dependentKeys)

Em.computed.or = (dependentKeys)->
  dependentKeys = Ember.makeArray(dependentKeys)

  computed = (->
    properties = @getProperties.apply(@, dependentKeys)

    for name, value of properties
      return true if value

    false
  )

  computed.property.apply(computed, dependentKeys)

Em.computed.map = (properties)->
  computed = (->
    for property, value of @getProperties(properties)
      if Ember.empty(value)
        null
      else
        value
  )

  computed.property.apply(computed, properties)

[tchak]

I am confused on the difference between or and any ? one of them should return the value where the other one juste a boolean?

[stefanpenner]

@tchak yup

[devinus]

All of this seems...so familiar...

[stefanpenner]

@devinus of what?

[devinus]

@stefanpenner Last time this came up.

[devinus]

And the time before that.

[devinus]

Also when it came up in SproutCore.

[devinus]

For the record, I love having common CP macros like this already available to me.

[chrisoverzero]

I also think that having these available would be useful. I was surprised to learn that computed properties can't be (for example) logically &&ed together:

showSummary: Ember.computed.bool('context.summary') && Ember.computed.bool('parentView.onIndex')

Having a clear, best alternative to what appears to be a sensible operation would be helpful.

[stefanpenner]

@chrisoverzero

current possible:

hasSummary: Ember.computed.bool('context.summary')
parentViewHasOnIndex: Ember.computed.bool('parentView.onInded')
showSummary: Ember.computed.and('hasSummary', 'parentViewHasOnIndex')

But you present an interesting idea. What if CP's where more more chainable.

hasSummary = Ember.computed.bool('context.summary')
parentViewHasOnIndex = Ember.computed.bool('parentView.onInded')

showSummary: hasSummary.and(parentViewHasOnIndex)

It would be interesting to explore.

[stefanpenner]

@tchak if you can add some tests for the new computed macro's I will merge these in.

[tchak]

@stefanpenner added some tests

[stefanpenner]

BOOOM

[karlguillotte]

Thank you @stefanpenner and @tchak. That is a nice addition to the API.