Class: ReactiveArray

Inherits:
Object show all
Includes:
ObjectTracking, ReactiveTags
Defined in:
lib/volt/reactive/reactive_array.rb

Overview

< Array

Direct Known Subclasses

ArrayModel

Instance Method Summary collapse

Methods included from ObjectTracking

#__setup_tracking

Methods included from ReactiveTags

included, #reactive_method_tag

Constructor Details

#initialize(array = []) ⇒ ReactiveArray

Returns a new instance of ReactiveArray.



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# File 'lib/volt/reactive/reactive_array.rb', line 7

def initialize(array=[])
  @array = array
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(method_name, *args, &block) ⇒ Object

Forward any missing methods to the array



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# File 'lib/volt/reactive/reactive_array.rb', line 12

def method_missing(method_name, *args, &block)
  @array.send(method_name, *args, &block)
end

Instance Method Details

#+(array) ⇒ Object 



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# File 'lib/volt/reactive/reactive_array.rb', line 91

def +(array)
  old_size = self.size
   
  # TODO: += is funky here, might need to make a .plus! method
  result = ReactiveArray.new(@array.dup + array)
  
  old_size.upto(result.size-1) do |index|
    trigger_for_index!('changed', index)
    trigger_on_direct_listeners!('added', old_size + index)
  end
  
  trigger_size_change!
  
  return result
end

#<<(value) ⇒ Object

alias :__old_append :<<



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# File 'lib/volt/reactive/reactive_array.rb', line 76

def <<(value)
  result = (@array << value)
  
  # Track new value
  __track_element(self.size-1, value)
  
  trigger_for_index!('changed', self.size-1)
  trigger_on_direct_listeners!('added', self.size-1)
  
  trigger_size_change!
  
  return result
end

#==(*args) ⇒ Object 



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# File 'lib/volt/reactive/reactive_array.rb', line 16

def ==(*args)
  @array.==(*args)
end

#[]=(index, value) ⇒ Object

alias :__old_assign :[]=



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# File 'lib/volt/reactive/reactive_array.rb', line 26

def []=(index, value)  
  index_val = index.cur  
  # Clean old value
  __clear_element(index)
  
  @array[index.cur] = value
  
  # Track new value
  __track_element(index, value)
  
  # Also track the index if its reactive
  if index.reactive?
    # TODO: Need to clean this up when the index changes
    event_chain.add_object(index.reactive_manager) do |event, *args|
      trigger_for_index!(event, index.cur)
    end
  end
  
  # Trigger changed
  trigger_for_index!('changed', index_val)
end

#delete_at(index) ⇒ Object

alias :__old_delete_at :delete_at



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# File 'lib/volt/reactive/reactive_array.rb', line 52

def delete_at(index)
  index_val = index.cur
  
  __clear_element(index)
  
  @array.delete_at(index_val)
  
  trigger_on_direct_listeners!('removed', index_val)
  
  # Trigger a changed event for each element in the zone where the 
  # lookup would change
  index.upto(self.size+1) do |position|
    trigger_for_index!('changed', position)
  end
  
  trigger_size_change!
end

#insert(*args) ⇒ Object

alias :__old_insert :insert



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# File 'lib/volt/reactive/reactive_array.rb', line 111

def insert(*args)
  old_size = self.size
  result = @array.insert(*args)

  old_size.upto(result.size-1) do |index|
    trigger_for_index!('changed', index)
    trigger_on_direct_listeners!('added', old_size+index)
  end
  
  trigger_size_change!
  
  return result
end

#inspect ⇒ Object 



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# File 'lib/volt/reactive/reactive_array.rb', line 202

def inspect
  "#<#{self.class.to_s} #{@array.inspect}>"
end

#split_scope(scope) ⇒ Object

TODO: This is an opal work around. Currently there is a bug with destructuring method_name, *args, block = scope



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# File 'lib/volt/reactive/reactive_array.rb', line 152

def split_scope(scope)
  if scope
    scope = scope.dup
    method_name = scope.shift
    block = scope.pop
  
    return method_name, scope, block
  else
    return nil,[],nil
  end
end

#trigger_for_index!(event_name, index, *passed_args) ⇒ Object

Trigger the changed event to any values fetched either through the lookup ([]), #last, or any fetched through the array its self. (sum, max, etc…)

On an array, when an element is added or removed, we need to trigger change events on each method that does the following:

  1. uses the whole array (max, sum, etc…)

  2. accesses this specific element - array

  3. accesses an element via a method (first, last)



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# File 'lib/volt/reactive/reactive_array.rb', line 171

def trigger_for_index!(event_name, index, *passed_args)
  self.trigger_by_scope!(event_name, *passed_args) do |scope|
    # method_name, *args, block = scope
    method_name, args, block = split_scope(scope)
    
    result = case method_name
    when nil
      # no method name means the event was bound directly, we don't
      # want to trigger changed on the array its self.
      false
    when :[]
      # Extract the current index if its reactive
      arg_index = args[0].cur
      
      # TODO: we could handle negative indicies better
      arg_index == index.cur || arg_index < 0
    when :last
      index.cur == self.size-1
    when :first
      index.cur == 0
    when :size, :length
      # Size does not depend on the contents of the cells
      false
    else
      true
    end
    
    result
  end
end

#trigger_on_direct_listeners!(event, *args) ⇒ Object 



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# File 'lib/volt/reactive/reactive_array.rb', line 125

def trigger_on_direct_listeners!(event, *args)
  trigger_by_scope!(event, *args) do |scope|
    # Only if it is bound directly to us.  Don't pass
    # down the chain
    !scope || scope[0] == nil
  end
  
end

#trigger_size_change! ⇒ Object 



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# File 'lib/volt/reactive/reactive_array.rb', line 134

def trigger_size_change!
  trigger_by_scope!('changed') do |scope|
    # method_name, *args, block = scope
    method_name, args, block = split_scope(scope)
    
    result = case method_name && method_name.to_sym
    when :size, :length
      true
    else
      false
    end
    
    result
  end
end