Class: Inversion::Template::ElsifTag

Inherits:
AttrTag show all
Defined in:
lib/inversion/template/elsiftag.rb

Overview

Inversion ‘elsif’ tag.

This tag adds a conditional logical switch to an IfTag. If the IfTag’s condition was false, but the attribute or methodchain of the elsif is true, start rendering.

Syntax

<?if attr ?>
    ...
<?elsif attr ?>
    ...
<?elsif attr.methodchain ?>
    ...
<?end?>

Constant Summary

Constants inherited from Tag

Tag::TAG_PLUGIN_PATTERN

Instance Attribute Summary collapse

Attributes inherited from AttrTag

#format, #methodchain, #name

Attributes inherited from CodeTag

#body, #identifiers

Attributes inherited from Tag

#body

Attributes inherited from Node

#colnum, #linenum

Instance Method Summary collapse

Methods inherited from AttrTag

#as_comment_body, #evaluate

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

#as_comment_body, 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, #as_comment_body, #is_container?, #location

Constructor Details

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

Create a new ElsifTag.



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# File 'lib/inversion/template/elsiftag.rb', line 45

def initialize( body, linenum=nil, colnum=nil )
  @inverted = false
  super
end

Instance Attribute Details

#inverted ⇒ Object

Invert the tag’s renderstate if created with the ‘not’ operator.



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# File 'lib/inversion/template/elsiftag.rb', line 51

def inverted
  @inverted
end

Instance Method Details

#before_appending(parsestate) ⇒ Object

Parsing callback – check to be sure the node tree can have an ‘elsif’ tag appended to it (i.e., it has an opening ‘if’ tag).



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# File 'lib/inversion/template/elsiftag.rb', line 56

def before_appending( parsestate )
  condtag = parsestate.node_stack.reverse.find do |node|
    case node
    when Inversion::Template::IfTag,
         Inversion::Template::CommentTag
      break node
    when Inversion::Template::ContainerTag
      raise Inversion::ParseError, "'%s' tags can't have '%s' clauses" %
        [ node.tagname.downcase, self.tagname.downcase ]
    end
  end

  unless condtag
    raise Inversion::ParseError, "orphaned '%s' tag" % [ self.tagname.downcase ]
  end
end

#before_rendering(renderstate) ⇒ Object

Toggle rendering for the elsiftag’s container if rendering hasn’t yet been toggled.



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# File 'lib/inversion/template/elsiftag.rb', line 82

def before_rendering( renderstate )

  evaluated_state = self.evaluate( renderstate )
  evaluated_state = ! evaluated_state if self.inverted

  if renderstate.tag_data[ :rendering_was_enabled ]
    self.log.debug "Rendering was previously enabled; disabling"
    renderstate.disable_rendering
  elsif evaluated_state
    self.log.debug "Rendering was previously disabled, and condition is true; enabling"
    renderstate.tag_data[ :rendering_was_enabled ] = true
    renderstate.enable_rendering
  end

  return nil
end

#render ⇒ Object

Always render as an empty string.



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# File 'lib/inversion/template/elsiftag.rb', line 75

def render( * )
  nil
end