require 'active_support/core_ext/module/attr_internal'
require 'active_support/core_ext/module/delegation'
require 'active_support/core_ext/class/attribute'
require 'active_support/ordered_options'
require 'action_view/log_subscriber'
module ActionView #:nodoc:
# = Action View Base
#
# Action View templates can be written in several ways. If the template file has a <tt>.erb</tt> extension then it uses a mixture of ERb
# (included in Ruby) and HTML. If the template file has a <tt>.builder</tt> extension then Jim Weirich's Builder::XmlMarkup library is used.
#
# == 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:
#
# <b>Names of all the people</b>
# <% @people.each do |person| %>
# Name: <%= person.name %><br/>
# <% 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:
#
# <%# WRONG %>
# Hi, Mr. <% puts "Frodo" %>
#
# If you absolutely must write from within a function use +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 <tt>@page_title</tt> variable and use it for outputting a title tag:
#
# <title><%= @page_title %></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 <tt>shared/header</tt> 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 <tt>defined? headline</tt> 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 in development mode.
#
# == 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 <tt>.builder</tt> extension.
#
# Here are some basic examples:
#
# xml.em("emphasized") # => <em>emphasized</em>
# xml.em { xml.b("emph & bold") } # => <em><b>emph & bold</b></em>
# xml.a("A Link", "href" => "http://onestepback.org") # => <a href="http://onestepback.org">A Link</a>
# xml.target("name" => "compile", "option" => "fast") # => <target option="fast" name="compile"\>
# # 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 do
# xml.h1(@person.name)
# xml.p(@person.bio)
# end
#
# would produce something like:
#
# <div>
# <h1>David Heinemeier Hansson</h1>
# <p>A product of Danish Design during the Winter of '79...</p>
# </div>
#
# 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"
#
# @recent_items.each do |item|
# 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.
class Base
include Helpers, ::ERB::Util, Context
# Specify the proc used to decorate input tags that refer to attributes with errors.
cattr_accessor :field_error_proc
@@field_error_proc = Proc.new{ |html_tag, instance| "<div class=\"field_with_errors\">#{html_tag}</div>".html_safe }
# How to complete the streaming when an exception occurs.
# This is our best guess: first try to close the attribute, then the tag.
cattr_accessor :streaming_completion_on_exception
@@streaming_completion_on_exception = %("><script type="text/javascript">window.location = "/500.html"</script></html>)
class_attribute :helpers
class_attribute :_routes
class_attribute :logger
class << self
delegate :erb_trim_mode=, :to => 'ActionView::Template::Handlers::ERB'
delegate :logger, :to => 'ActionController::Base', :allow_nil => true
def cache_template_loading
ActionView::Resolver.caching?
end
def cache_template_loading=(value)
ActionView::Resolver.caching = value
end
def xss_safe? #:nodoc:
true
end
# This method receives routes and helpers from the controller
# and return a subclass ready to be used as view context.
def prepare(routes, helpers) #:nodoc:
Class.new(self) do
if routes
include routes.url_helpers
include routes.mounted_helpers
end
if helpers
include helpers
self.helpers = helpers
end
end
end
end
attr_accessor :view_renderer
attr_internal :config, :assigns
delegate :lookup_context, :to => :view_renderer
delegate :formats, :formats=, :locale, :locale=, :view_paths, :view_paths=, :to => :lookup_context
def assign(new_assigns) # :nodoc:
@_assigns = new_assigns.each { |key, value| instance_variable_set("@#{key}", value) }
end
def initialize(context = nil, assigns = {}, controller = nil, formats = nil) #:nodoc:
@_config = ActiveSupport::InheritableOptions.new
# Handle all these for backwards compatibility.
# TODO Provide a new API for AV::Base and deprecate this one.
if context.is_a?(ActionView::Renderer)
@view_renderer = context
elsif
lookup_context = context.is_a?(ActionView::LookupContext) ?
context : ActionView::LookupContext.new(context)
lookup_context.formats = formats if formats
lookup_context.prefixes = controller._prefixes if controller
@view_renderer = ActionView::Renderer.new(lookup_context)
end
assign(assigns)
assign_controller(controller)
_prepare_context
end
ActiveSupport.run_load_hooks(:action_view, self)
end
end
