Class: Inversion::Template::ForTag

Inherits:
CodeTag show all
Includes:
ContainerTag
Defined in:
lib/inversion/template/fortag.rb

Overview

Inversion ‘for’ tag.

Iteration tag for outputting a template part for each member of a collection (i.e., an object that is Enumerable).

Syntax

<?for var in attribute ?>
<?for var in attribute.methodchain ?>
<?for var1, var2 in attribute.methodchain ?>

Examples

<?for employee in company.employees ?>

Hey <?call employee.name ?>! You're fired!

<?end ?>

Constant Summary

Constants inherited from Tag

Tag::TAG_PLUGIN_PATTERN

Instance Attribute Summary collapse

Attributes included from ContainerTag

#subnodes

Attributes inherited from CodeTag

#body, #identifiers

Attributes inherited from Tag

#body

Attributes inherited from Node

#colnum, #linenum

Instance Method Summary collapse

Methods included from ContainerTag

#<<, #is_container?, #render_subnodes

Methods inherited from CodeTag

inherit_tag_patterns, tag_pattern, tag_patterns

Methods included from AbstractClass

included

Methods included from AbstractClass::ClassMethods

#inherited, #pure_virtual

Methods inherited from Tag

create, #derivatives, inherited, load, load_all, #tagname, types, #types

Methods included from MethodUtilities

#singleton_attr_accessor, #singleton_attr_reader, #singleton_attr_writer

Methods inherited from Node

#after_appending, #after_rendering, #before_appending, #before_rendering, #is_container?, #location

Constructor Details

#initialize(body, linenum = nil, colnum = nil) ⇒ ForTag

Create a new ForTag with the specified ‘body`.



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# File 'lib/inversion/template/fortag.rb', line 62

def initialize( body, linenum=nil, colnum=nil )
  @block_args = []
  @enumerator = nil

  super( 'for ' + body, linenum, colnum )
end

Instance Attribute Details

#block_args ⇒ Object

The array of attribute names that will be assigned to the rendering scope by the block for each iteration



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# File 'lib/inversion/template/fortag.rb', line 76

def block_args
  @block_args
end

#enumerator ⇒ Object

The attribute or methodchain that yields the enumerable object



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# File 'lib/inversion/template/fortag.rb', line 79

def enumerator
  @enumerator
end

Instance Method Details

#as_comment_body ⇒ Object

Render the tag as the body of a comment, suitable for template debugging.



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# File 'lib/inversion/template/fortag.rb', line 115

def as_comment_body
  comment = "%s: { %s IN template.%s }" % [
    self.tagname,
    self.block_args.join(', '),
    self.enumerator
  ]

  return comment
end

#render(state) ⇒ Object

Iterate over the enumerator in ‘state` and render the tag’s contents for each iteration.



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# File 'lib/inversion/template/fortag.rb', line 84

def render( state )
  lvalue = state.eval( self.enumerator ) or return nil
  lvalue = lvalue.each unless lvalue.respond_to?( :next )

  self.log.debug "Rendering %p via block args: %p" % [ lvalue, self.block_args ]

  # Loop will exit as soon as the Enumerator runs out of elements
  loop do
    args = lvalue.next

    # Turn the block arguments into an overrides hash by zipping up
    # the arguments names and values
    overrides = if self.block_args.size > 1
        args = [ args ] unless args.is_a?( Array )
        Hash[ self.block_args.zip(args) ]
      else
        { self.block_args.first => args }
      end

    # Overlay the block args from the 'for' over the template attributes and render
    # each subnode
    state.with_attributes( overrides ) do
      super
    end
  end

  return nil
end