Class: Inversion::Template::ElseTag

Inherits:
Tag
  • Object
show all
Defined in:
lib/inversion/template/elsetag.rb

Overview

Inversion ‘else’ tag.

This tag adds a logical switch to an IfTag. If the IfTag’s condition was false, start rendering.

Syntax

<?if attr ?>
    ...
<?else ?>
    ...
<?end?>

Constant Summary

Constants inherited from Tag

Tag::TAG_PLUGIN_PATTERN

Instance Attribute Summary

Attributes inherited from Tag

#body

Attributes inherited from Node

#colnum, #linenum

Instance Method Summary collapse

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 included from AbstractClass

included

Methods included from AbstractClass::ClassMethods

#inherited, #pure_virtual

Methods inherited from Node

#after_appending, #after_rendering, #as_comment_body, #is_container?, #location

Constructor Details

#initialize(body = '', linenum = nil, colnum = nil) ⇒ ElseTag

Overridden to default body to nothing, and raise an error if it has one.

Raises:



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# File 'lib/inversion/template/elsetag.rb', line 25

def initialize( body='', linenum=nil, colnum=nil ) # :notnew:
  raise Inversion::ParseError, "else can't have a condition" unless body.to_s.strip == ''
  super
end

Instance Method Details

#before_appending(parsestate) ⇒ Object

Parsing callback – check to be sure the node tree can have an ‘else’ tag appended to it.

Raises:



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# File 'lib/inversion/template/elsetag.rb', line 38

def before_appending( parsestate )
  condtag = parsestate.node_stack.reverse.find do |node|
    case node

    # If there was a previous 'if' or 'unless', the else belongs to it. Also
    # allow it to be appended to a 'comment' section so you can comment out an
    # else clause
    when Inversion::Template::IfTag,
         Inversion::Template::UnlessTag,
         Inversion::Template::CommentTag
      break node

    # If it's some other kind of container, it's an error
    when Inversion::Template::ContainerTag
      raise Inversion::ParseError, "'%s' tags can't have '%s' clauses" %
        [ node.tagname.downcase, self.tagname.downcase ]
    end
  end

  # If there wasn't a valid container, it's an error too
  raise Inversion::ParseError, "orphaned '%s' tag" % [ self.tagname.downcase ] unless condtag
end

#before_rendering(renderstate) ⇒ Object

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



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# File 'lib/inversion/template/elsetag.rb', line 70

def before_rendering( renderstate )
  if renderstate.tag_data[ :rendering_was_enabled ]
    self.log.debug "  rendering was previously enabled: disabling"
    renderstate.disable_rendering
  else
    self.log.debug "  rendering was previously disabled: enabling"
    renderstate.tag_data[ :rendering_was_enabled ] = true
    renderstate.enable_rendering
  end

  return nil
end

#render ⇒ Object

Always remder as an empty string.



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# File 'lib/inversion/template/elsetag.rb', line 63

def render( * )
  nil
end