Class: AttributeBinding

Inherits:
BaseBinding show all
Defined in:
lib/volt/page/bindings/attribute_binding.rb

Instance Attribute Summary

Attributes inherited from BaseBinding

#binding_name, #context, #target

Instance Method Summary collapse

Methods inherited from BaseBinding

#dom_section, #queue_update, #value_from_getter

Constructor Details

#initialize(page, target, context, binding_name, attribute_name, getter) ⇒ AttributeBinding

Returns a new instance of AttributeBinding.



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# File 'lib/volt/page/bindings/attribute_binding.rb', line 5

def initialize(page, target, context, binding_name, attribute_name, getter)
  super(page, target, context, binding_name)

  @attribute_name = attribute_name
  @getter = getter

  setup
end

Instance Method Details

#changed(event = nil) ⇒ Object 



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# File 'lib/volt/page/bindings/attribute_binding.rb', line 35

def changed(event=nil)
  case @attribute_name
  when 'value'
    current_value = element.value
  else
    current_value = element.is(':checked')
  end

  @value.cur = current_value
end

#element ⇒ Object 



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# File 'lib/volt/page/bindings/attribute_binding.rb', line 46

def element
  Element.find('#' + binding_name)
end

#remove ⇒ Object 



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# File 'lib/volt/page/bindings/attribute_binding.rb', line 89

def remove
  # Unbind events, leave the element there since attribute bindings
  # aren't responsible for it being there.
  case @attribute_name
  when 'value'
    element.off('input.attrbind', nil)
  when 'checked'
    element.off('change.attrbind', nil)
  end

  # Value is a reactive template, remove it
  if @value && @value.reactive?
    @value.remove
  end


  if @update_listener
    @update_listener.remove
    @update_listener = nil
  end

  # Clear any references
  @target = nil
  @context = nil
  @getter = nil
  @value = nil
end

#remove_anchors ⇒ Object 



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# File 'lib/volt/page/bindings/attribute_binding.rb', line 117

def remove_anchors
  raise "attribute bindings do not have anchors, can not remove them"
end

#setup ⇒ Object 



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# File 'lib/volt/page/bindings/attribute_binding.rb', line 14

def setup

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

  # Run the initial update (render)
  update

  if @value.reactive?
    @update_listener = @value.on('changed') { update }

    # Bind so when this value updates, we update
    case @attribute_name
    when 'value'
      element.on('input.attrbind') { changed }
    when 'checked'
      element.on('change.attrbind') {|event| changed(event) }
    end
  end
end

#update ⇒ Object 



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# File 'lib/volt/page/bindings/attribute_binding.rb', line 50

def update
  value = @value.cur

  if @attribute_name == 'checked'
    update_checked
    return
  end

  if value.is_a?(NilMethodCall) || value.nil?
    value = ''
  end

  self.value = value
end

#update_checked ⇒ Object 



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# File 'lib/volt/page/bindings/attribute_binding.rb', line 78

def update_checked
  value = @value.cur

  if value.is_a?(NilMethodCall) || value.nil?
    value = false
  end

  element.prop('checked', value)

end

#value=(val) ⇒ Object 



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# File 'lib/volt/page/bindings/attribute_binding.rb', line 65

def value=(val)
  case @attribute_name
  when 'value'
    # TODO: only update if its not the same, this keeps it from moving the
    # cursor in text fields.
    if val != element.value
      element.value = val
    end
  else
    element[@attribute_name] = val
  end
end