Class: Trellis::Renderer

Inherits:
Object show all
Includes:
Radius
Defined in:
lib/trellis/trellis.rb

Overview

– Renderer – Responsible for processing tags/components in the page templates Uses the Radius context object onto which components registered themselves (the tags that they respond to)

Constant Summary collapse

SKIP_METHODS = 
['before_load', 'after_load', 'before_render', 'after_render', 'get']
INCLUDE_METHODS = 
['render_partial']

Instance Method Summary collapse

Constructor Details

#initialize(page) ⇒ Renderer

Returns a new instance of Renderer.



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# File 'lib/trellis/trellis.rb', line 832

def initialize(page)
  @page = page
  @context = Context.new
  # context for erubis templates
  @eruby_context = Erubis::Context.new #if @page.class.format == :eruby
  
  # add all instance variables in the page as values accesible from the tags
  page.instance_variables.each do |var|
    value = page.instance_variable_get(var)
    unless value.kind_of?(Trellis::Page)
      sym = "#{var}=".split('@').last.to_sym
      @context.globals.send(sym, value)
      @eruby_context["#{var}".split('@').last] = value #if @eruby_context
    end
  end

  # add other useful values to the tag context
  @context.globals.send(:page_name=, page.class.to_s)
  @eruby_context[:page_name] = page.class.to_s #if @eruby_context

  # add public page methods to the context
  page.public_methods(false).each do |method_name|
    # skip event handlers and the 'get' method
    unless method_name.starts_with?('on_') || SKIP_METHODS.include?(method_name)
      @eruby_context.meta_def(method_name) do |*args|
        page.send(method_name.to_sym, *args)
      end #if @eruby_context
      @context.globals.meta_def(method_name) do |*args|
        page.send(method_name.to_sym, *args)
      end
    end 
  end
  
  # add page helper methods to the context
  INCLUDE_METHODS.each do |method_name|
    @eruby_context.meta_def(method_name) do |*args|
      page.send(method_name.to_sym, *args)
    end #if @eruby_context
    @context.globals.meta_def(method_name) do |*args|
      page.send(method_name.to_sym, *args)
    end
  end
  
  # add public application methods to the context
  page.application.public_methods(false).each do |method_name|
    @eruby_context.meta_def(method_name) do |*args|
      page.application.send(method_name.to_sym, *args)
    end #if @eruby_context
    @context.globals.meta_def(method_name) do |*args|
      page.application.send(method_name.to_sym, *args)
    end        
  end

  # add the page to the context too
  @context.globals.page = page
  @eruby_context[:page] = page #if @eruby_context
  
  # register the components contained in the page with the renderer's context
  page.class.components.each do |component|
    component.register_with_tag_context(@context)
  end 
  
  @parser = Parser.new(@context, :tag_prefix => 'trellis')
end

Instance Method Details

#render ⇒ Object 



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# File 'lib/trellis/trellis.rb', line 897

def render
  preprocessed = ""
  layout_id = @page.class.layout
  template = layout_id ? @page.class.to_xml(:no_declaration => true) : @page.class.to_xml

  if layout_id
    # page has a layout 
    # retrieve the layout from the application
    layout = Application.layouts[layout_id]
    # render the page template to a variable
    if @page.class.format == :eruby
      body = Erubis::PI::Eruby.new(template, :trim => false).evaluate(@eruby_context)
      @eruby_context[:body] = body
    else
      @eruby_context[:body] = template
    end
    
    # render the layout around the page template
    preprocessed = Erubis::PI::Eruby.new(layout.to_xml, :trim => false).evaluate(@eruby_context)
    
    # clean up nokogiri namespace hack, see Page#template
    doc = Nokogiri::XML(preprocessed)
    to_be_removed = doc.at_css(%[div[id="trellis_remove"]])
    parent = to_be_removed.parent
    to_be_removed.children.each { |child| child.parent = parent }
    to_be_removed.remove
    preprocessed = doc.to_xml
  else
    # page has no layout
    if @page.class.format == :eruby
      preprocessed = Erubis::PI::Eruby.new(template, :trim => false).evaluate(@eruby_context)
    else
      preprocessed = template
    end
  end
  # radius parsing
  @parser.parse(preprocessed)
end

#render_partial(name, locals = {}) ⇒ Object 



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# File 'lib/trellis/trellis.rb', line 936

def render_partial(name, locals={})
  partial = Application.partials[name]
  if partial
    if partial.format == :eruby
      locals.each_pair { |n,v| @eruby_context[n] = v }
      preprocessed = Erubis::PI::Eruby.new(partial.to_xml, :trim => false).evaluate(@eruby_context)
      @parser.parse(preprocessed)
    else
      @parser.parse(partial.to_xml)
    end        
  end
end