module ActionView #:nodoc:
class ActionViewError < StandardError #:nodoc:
end
class MissingTemplate < ActionViewError #:nodoc:
attr_reader :path
def initialize(paths, path, template_format = nil)
@path = path
full_template_path = path.include?('.') ? path : "#{path}.erb"
display_paths = paths.compact.join(":")
template_type = (path =~ /layouts/i) ? 'layout' : 'template'
super("Missing #{template_type} #{full_template_path} in view path #{display_paths}")
end
end
# Action View templates can be written in three ways. If the template file has a .erb (or .rhtml) extension then it uses a mixture of ERb
# (included in Ruby) and HTML. If the template file has a .builder (or .rxml) extension then Jim Weirich's Builder::XmlMarkup library is used.
# If the template file has a .rjs extension then it will use ActionView::Helpers::PrototypeHelper::JavaScriptGenerator.
#
# = ERb
#
# You trigger ERb by using embeddings such as <% %>, <% -%>, and <%= %>. The <%= %> tag set is used when you want output. Consider the
# following loop for names:
#
# Names of all the people
# <% for person in @people %>
# Name: <%= person.name %>
# <% end %>
#
# The loop is setup in regular embedding tags <% %> and the name is written using the output embedding tag <%= %>. Note that this
# is not just a usage suggestion. Regular output functions like print or puts won't work with ERb templates. So this would be wrong:
#
# Hi, Mr. <% puts "Frodo" %>
#
# If you absolutely must write from within a function, you can use the TextHelper#concat.
#
# <%- and -%> suppress leading and trailing whitespace, including the trailing newline, and can be used interchangeably with <% and %>.
#
# == Using sub templates
#
# Using sub templates allows you to sidestep tedious replication and extract common display structures in shared templates. The
# classic example is the use of a header and footer (even though the Action Pack-way would be to use Layouts):
#
# <%= render "shared/header" %>
# Something really specific and terrific
# <%= render "shared/footer" %>
#
# As you see, we use the output embeddings for the render methods. The render call itself will just return a string holding the
# result of the rendering. The output embedding writes it to the current template.
#
# But you don't have to restrict yourself to static includes. Templates can share variables amongst themselves by using instance
# variables defined using the regular embedding tags. Like this:
#
# <% @page_title = "A Wonderful Hello" %>
# <%= render "shared/header" %>
#
# Now the header can pick up on the @page_title variable and use it for outputting a title tag:
#
#
<%= @page_title %>
#
# == Passing local variables to sub templates
#
# You can pass local variables to sub templates by using a hash with the variable names as keys and the objects as values:
#
# <%= render "shared/header", { :headline => "Welcome", :person => person } %>
#
# These can now be accessed in shared/header with:
#
# Headline: <%= headline %>
# First name: <%= person.first_name %>
#
# If you need to find out whether a certain local variable has been assigned a value in a particular render call,
# you need to use the following pattern:
#
# <% if local_assigns.has_key? :headline %>
# Headline: <%= headline %>
# <% end %>
#
# Testing using defined? headline will not work. This is an implementation restriction.
#
# == Template caching
#
# By default, Rails will compile each template to a method in order to render it. When you alter a template, Rails will
# check the file's modification time and recompile it.
#
# == Builder
#
# Builder templates are a more programmatic alternative to ERb. They are especially useful for generating XML content. An XmlMarkup object
# named +xml+ is automatically made available to templates with a .builder extension.
#
# Here are some basic examples:
#
# xml.em("emphasized") # => emphasized
# xml.em { xml.b("emph & bold") } # => emph & bold
# xml.a("A Link", "href"=>"http://onestepback.org") # => A Link
# xml.target("name"=>"compile", "option"=>"fast") # =>
# # NOTE: order of attributes is not specified.
#
# Any method with a block will be treated as an XML markup tag with nested markup in the block. For example, the following:
#
# xml.div {
# xml.h1(@person.name)
# xml.p(@person.bio)
# }
#
# would produce something like:
#
#
#
David Heinemeier Hansson
#
A product of Danish Design during the Winter of '79...
#
#
# A full-length RSS example actually used on Basecamp:
#
# xml.rss("version" => "2.0", "xmlns:dc" => "http://purl.org/dc/elements/1.1/") do
# xml.channel do
# xml.title(@feed_title)
# xml.link(@url)
# xml.description "Basecamp: Recent items"
# xml.language "en-us"
# xml.ttl "40"
#
# for item in @recent_items
# xml.item do
# xml.title(item_title(item))
# xml.description(item_description(item)) if item_description(item)
# xml.pubDate(item_pubDate(item))
# xml.guid(@person.firm.account.url + @recent_items.url(item))
# xml.link(@person.firm.account.url + @recent_items.url(item))
#
# xml.tag!("dc:creator", item.author_name) if item_has_creator?(item)
# end
# end
# end
# end
#
# More builder documentation can be found at http://builder.rubyforge.org.
#
# == JavaScriptGenerator
#
# JavaScriptGenerator templates end in .rjs. Unlike conventional templates which are used to
# render the results of an action, these templates generate instructions on how to modify an already rendered page. This makes it easy to
# modify multiple elements on your page in one declarative Ajax response. Actions with these templates are called in the background with Ajax
# and make updates to the page where the request originated from.
#
# An instance of the JavaScriptGenerator object named +page+ is automatically made available to your template, which is implicitly wrapped in an ActionView::Helpers::PrototypeHelper#update_page block.
#
# When an .rjs action is called with +link_to_remote+, the generated JavaScript is automatically evaluated. Example:
#
# link_to_remote :url => {:action => 'delete'}
#
# The subsequently rendered delete.rjs might look like:
#
# page.replace_html 'sidebar', :partial => 'sidebar'
# page.remove "person-#{@person.id}"
# page.visual_effect :highlight, 'user-list'
#
# This refreshes the sidebar, removes a person element and highlights the user list.
#
# See the ActionView::Helpers::PrototypeHelper::GeneratorMethods documentation for more details.
class Base
include Helpers, Partials, ::ERB::Util
extend ActiveSupport::Memoizable
attr_accessor :base_path, :assigns, :template_extension
attr_accessor :controller
attr_writer :template_format
attr_accessor :output_buffer
class << self
delegate :erb_trim_mode=, :to => 'ActionView::TemplateHandlers::ERB'
delegate :logger, :to => 'ActionController::Base'
end
@@debug_rjs = false
##
# :singleton-method:
# Specify whether RJS responses should be wrapped in a try/catch block
# that alert()s the caught exception (and then re-raises it).
cattr_accessor :debug_rjs
# Specify whether templates should be cached. Otherwise the file we be read everytime it is accessed.
# Automaticaly reloading templates are not thread safe and should only be used in development mode.
@@cache_template_loading = false
cattr_accessor :cache_template_loading
def self.cache_template_loading?
ActionController::Base.allow_concurrency || cache_template_loading
end
attr_internal :request
delegate :request_forgery_protection_token, :template, :params, :session, :cookies, :response, :headers,
:flash, :logger, :action_name, :controller_name, :to => :controller
module CompiledTemplates #:nodoc:
# holds compiled template code
end
include CompiledTemplates
def self.process_view_paths(value)
ActionView::PathSet.new(Array(value))
end
attr_reader :helpers
class ProxyModule < Module
def initialize(receiver)
@receiver = receiver
end
def include(*args)
super(*args)
@receiver.extend(*args)
end
end
def initialize(view_paths = [], assigns_for_first_render = {}, controller = nil)#:nodoc:
@assigns = assigns_for_first_render
@assigns_added = nil
@_render_stack = []
@controller = controller
@helpers = ProxyModule.new(self)
self.view_paths = view_paths
end
attr_reader :view_paths
def view_paths=(paths)
@view_paths = self.class.process_view_paths(paths)
# we might be using ReloadableTemplates, so we need to let them know this a new request
@view_paths.load!
end
# Returns the result of a render that's dictated by the options hash. The primary options are:
#
# * :partial - See ActionView::Partials.
# * :update - Calls update_page with the block given.
# * :file - Renders an explicit template file (this used to be the old default), add :locals to pass in those.
# * :inline - Renders an inline template similar to how it's done in the controller.
# * :text - Renders the text passed in out.
#
# If no options hash is passed or :update specified, the default is to render a partial and use the second parameter
# as the locals hash.
def render(options = {}, local_assigns = {}, &block) #:nodoc:
local_assigns ||= {}
case options
when Hash
options = options.reverse_merge(:locals => {})
if options[:layout]
_render_with_layout(options, local_assigns, &block)
elsif options[:file]
template = self.view_paths.find_template(options[:file], template_format)
template.render_template(self, options[:locals])
elsif options[:partial]
render_partial(options)
elsif options[:inline]
InlineTemplate.new(options[:inline], options[:type]).render(self, options[:locals])
elsif options[:text]
options[:text]
end
when :update
update_page(&block)
else
render_partial(:partial => options, :locals => local_assigns)
end
end
# The format to be used when choosing between multiple templates with
# the same name but differing formats. See +Request#template_format+
# for more details.
def template_format
if defined? @template_format
@template_format
elsif controller && controller.respond_to?(:request)
@template_format = controller.request.template_format.to_sym
else
@template_format = :html
end
end
# Access the current template being rendered.
# Returns a ActionView::Template object.
def template
@_render_stack.last
end
private
# Evaluates the local assigns and controller ivars, pushes them to the view.
def _evaluate_assigns_and_ivars #:nodoc:
unless @assigns_added
@assigns.each { |key, value| instance_variable_set("@#{key}", value) }
_copy_ivars_from_controller
@assigns_added = true
end
end
def _copy_ivars_from_controller #:nodoc:
if @controller
variables = @controller.instance_variable_names
variables -= @controller.protected_instance_variables if @controller.respond_to?(:protected_instance_variables)
variables.each { |name| instance_variable_set(name, @controller.instance_variable_get(name)) }
end
end
def _set_controller_content_type(content_type) #:nodoc:
if controller.respond_to?(:response)
controller.response.content_type ||= content_type
end
end
def _render_with_layout(options, local_assigns, &block) #:nodoc:
partial_layout = options.delete(:layout)
if block_given?
begin
@_proc_for_layout = block
concat(render(options.merge(:partial => partial_layout)))
ensure
@_proc_for_layout = nil
end
else
begin
original_content_for_layout = @content_for_layout if defined?(@content_for_layout)
@content_for_layout = render(options)
if (options[:inline] || options[:file] || options[:text])
@cached_content_for_layout = @content_for_layout
render(:file => partial_layout, :locals => local_assigns)
else
render(options.merge(:partial => partial_layout))
end
ensure
@content_for_layout = original_content_for_layout
end
end
end
end
end