Class: Wee::ComponentRunner

Inherits:
Object show all
Defined in:
lib/wee/core/componentrunner.rb

Overview

Wee::ComponentRunner wraps a root component and provides methods that act on the components tree defined by the root component.

Direct Known Subclasses

PagelessComponentDriver

Constant Summary collapse

DEFAULT_CALLBACK_PROCESSING =

Values are parameters to method #process_callbacks_of

[
  # Invokes all specified input callbacks. NOTE: Input callbacks should never
  # call other components!
  [:input, true, false],

  # Invokes the first found action callback. NOTE: Only the first action
  # callback is invoked. Any other action callback is ignored.
  [:action, false, true],
  
  # Invoke live_update callback (NOTE: only the first is invoked).
  [:live_update, false, true]
]

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(root_component) ⇒ ComponentRunner

Returns a new instance of ComponentRunner.



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# File 'lib/wee/core/componentrunner.rb', line 23

def initialize(root_component)
  @root_component = root_component
  @callback_processing = DEFAULT_CALLBACK_PROCESSING 
end

Instance Attribute Details

#root_component ⇒ Object

Returns the value of attribute root_component.



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# File 'lib/wee/core/componentrunner.rb', line 21

def root_component
  @root_component
end

Instance Method Details

#process_callbacks(callback_stream) ⇒ Object

This method triggers several tree traversals to process the callbacks of the root component.

Returns nil or a Response object in case of a premature response.



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# File 'lib/wee/core/componentrunner.rb', line 47

def process_callbacks(callback_stream)
  if callback_stream.all_of_type(:action).size > 1 
    raise "Not allowed to specify more than one action callback"
  end

  catch(:wee_abort_callback_processing) { 
    @callback_processing.each {|args| process_callbacks_of(callback_stream, *args) }
    nil
  }
end

#render(rendering_context) ⇒ Object

Render the root component with the given rendering context.



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# File 'lib/wee/core/componentrunner.rb', line 38

def render(rendering_context)
  @root_component.do_render_chain(rendering_context)
end

#snapshot ⇒ Object

This method takes a snapshot from the current state of the root component and returns it.



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# File 'lib/wee/core/componentrunner.rb', line 31

def snapshot
  @root_component.backtrack_state_chain(snap = Wee::Snapshot.new)
  return snap.freeze
end