Class: EachBinding

Inherits:
BaseBinding show all
Defined in:
lib/volt/templates/each_binding.rb

Instance Attribute Summary

Attributes inherited from BaseBinding

#binding_name, #context, #target

Instance Method Summary collapse

Methods inherited from BaseBinding

#queue_update, #remove_anchors, #section, #value_from_getter

Constructor Details

#initialize(target, context, binding_name, getter, variable_name, template_name) ⇒ EachBinding

Returns a new instance of EachBinding.



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# File 'lib/volt/templates/each_binding.rb', line 4

def initialize(target, context, binding_name, getter, variable_name, template_name)
  # puts "New EACH Binding"

  super(target, context, binding_name)

  @item_name = variable_name
  @template_name = template_name

  # Find the source for the content binding
  @value = value_from_getter(getter)

  @templates = []

  # Run the initial render
  update

  @added_listener = @value.on('added') { |position, item| puts "ADDED" ; item_added(position) }
  @changed_listener = @value.on('changed') { puts "CHANGED" ; reload }
  @removed_listener = @value.on('removed') { |position| puts "REMOVED at #{position.inspect}" ; item_removed(position) }
end

Instance Method Details

#item_added(position) ⇒ Object 



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# File 'lib/volt/templates/each_binding.rb', line 65

def item_added(position)
  # puts "ADDED AT #{position}"
  binding_name = @@binding_number
  @@binding_number += 1

  # Setup new bindings in the spot we want to insert the item
  section.insert_anchor_before_end(binding_name)

  index = ReactiveValue.new(position)
  value = @value[index]
  
  item_context = SubContext.new({@item_name => value, :index => index, :parent => @value}, @context)

  @templates << TemplateRenderer.new(@target, item_context, binding_name, @template_name)
end

#item_removed(position) ⇒ Object 



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# File 'lib/volt/templates/each_binding.rb', line 43

def item_removed(position)
  position = position.cur
  @templates[position].remove
  @templates[position].remove_anchors
  @templates.delete_at(position)
  
  value_obj = @value.cur
  
  if value_obj
    size = value_obj.size - 1
  else
    size = 0
  end
  
  # puts "Position: #{position} to #{size}"
  
  # Removed at the position, update context for every item after this position
  position.upto(size) do |index|
    @templates[index].context.locals[:index].cur = index
  end
end

#reload ⇒ Object

When a change event comes through, its most likely upstream, so the whole array might have changed. In this case, just reload the whole thing TODO: Track to make sure the changed event isn’t being called too often (it is currently)



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# File 'lib/volt/templates/each_binding.rb', line 28

def reload
  # Remove all of the current templates
  if @templates
    @templates.each do |template|
      template.remove
      template.remove_anchors
    end
  end
  
  @templates = []
  
  # Run update again to rebuild
  update
end

#remove ⇒ Object

When this each_binding is removed, cleanup.



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# File 'lib/volt/templates/each_binding.rb', line 97

def remove
  # puts "Remove Each"
  @added_listener.remove
  @added_listener = nil
  
  @changed_listener.remove
  @changed_listener = nil
  
  @removed_listener.remove
  @removed_listener = nil

  @templates.each(&:remove)
  @templates = nil
  
  super
end

#update(item = nil) ⇒ Object 



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# File 'lib/volt/templates/each_binding.rb', line 81

def update(item=nil)
  if item
    values = [item]
  else
    values = @value.cur
    return if values.is_a?(Model) || values.is_a?(Exception)
    values = values.attributes
  end

  # TODO: Switch to #each?
  values.each_with_index do |value,index|
    item_added(index)
  end
end