Cosmos Blaze This

Provides a consistent this to all cosmos:blaze-profiles functions.

Added options for all functions so this functionality requires specifying this:true in the options. Then, all existing uses of the standard functions are not affected.

Install

meteor add cosmos:blaze-this

This

The this always has:

1. template - the template instance, Blaze.TemplateInstance
2. data - the current non-reactive data object
3. getData - reactive access to current data and parent data contexts
4. Template - the Blaze.Template object, for example: Template.theName

Conditionally has:

1. event - when it's an event listener
2. args - when it's a helper, event listener, or a functions function receiving arguments
3. hash - when it's a helper and an object is provided to the helper. The hash property is extracted from the Spacebars.kw argument and provided in the this; the Spacebars.kw object is removed from the args
4. subscribe - when it's a lifecycle listener (created and rendered)
5. autorun - when it's a lifecycle listener (created and rendered)
6. functions specified via the template.functions() function or an added profile

Usage

The this will be as described above for all functions added via:

1. Template.profiles()
2. Template.helpers()
3. Template.events()
4. Template.onCreated()
5. Template.onRendered()
6. Template.onDestroyed()
7. Template.functions()

For example:

# instead of passing a function, pass an object which contains `this` and `fn`
Template.onCreated this:true, fn: ->
    object = SomeCollection.findOne this.data.objectId
    this.template.$myObject = object

# provide options with this:true as `$options`    
Template.helpers
  $options: this:true
  name: -> this.template.$myObject.name

# provide options with this:true as `$options`    
Template.events
  $options: this:true
  name: -> this.template.$myObject.name

  # instead of passing a function, pass an object which contains `this` and `fn`
Template.onDestroyed this:true, fn: ->
  delete this.template.$myObject

The Standard This (without blaze-this)

Traditionally the this and other objects are done differently for different types. Describe:

1. Events:

   • this = the current Blaze.TemplateInstance data context
   • event - the first function arg
   • template - the second function arg
   • data (non-reactive) = this
   • data (reactive) = Template.currentData() and Template.parentData()
   • Template - template.view.template is the Blaze.Template

2. Helpers:

   • this = the current Blaze.TemplateInstance data context
   • template = Template.instance()
   • data (non-reactive) = the this
   • data (reactive) = Template.currentData() and Template.parentData()
   • Template - Template.instance().view.template is the Blaze.Template

3. Lifecycle handlers:

   • this = the current Blaze.TemplateInstance
   • template = this
   • data (non-reactive) = this.data
   • data (reactive) = Template.currentData() and Template.parentData()
   • Template - this.view.template is the Blaze.Template

API

There is no additional API. It alters the inner workings of cosmos:blaze-profiles to call functions with the this described above.

Well, there's one function to explain which is available in the this:

getData(number)

To reactively get data contexts we normally use Template.currentData() and Template.parentData(number).

Those two functionalities are combined via getData(number). It calls Template.parentData with a default number of zero.

So:

• getData(0) = Template.currentData()
• getData(1) = Template.parentData() and Template.parentData(1)
• getData(2) = Template.parentData(2)
• getData(3) = Template.parentData(3)
• and so on...

MIT License