545 lines
22 KiB
Ruby
545 lines
22 KiB
Ruby
require 'erb'
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module ActionView #:nodoc:
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class ActionViewError < StandardError #:nodoc:
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end
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# Action View templates can be written in three ways. If the template file has a +.rhtml+ extension then it uses a mixture of ERb
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# (included in Ruby) and HTML. If the template file has a +.rxml+ extension then Jim Weirich's Builder::XmlMarkup library is used.
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# If the template file has a +.rjs+ extension then it will use ActionView::Helpers::PrototypeHelper::JavaScriptGenerator.
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#
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# = ERb
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#
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# You trigger ERb by using embeddings such as <% %>, <% -%>, and <%= %>. The <%= %> tag set is used when you want output. Consider the
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# following loop for names:
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#
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# <b>Names of all the people</b>
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# <% for person in @people %>
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# Name: <%= person.name %><br/>
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# <% end %>
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#
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# The loop is setup in regular embedding tags <% %> and the name is written using the output embedding tag <%= %>. Note that this
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# is not just a usage suggestion. Regular output functions like print or puts won't work with ERb templates. So this would be wrong:
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#
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# Hi, Mr. <% puts "Frodo" %>
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#
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# If you absolutely must write from within a function, you can use the TextHelper#concat
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#
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# <%- and -%> suppress leading and trailing whitespace, including the trailing newline, and can be used interchangeably with <% and %>.
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#
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# == Using sub templates
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#
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# Using sub templates allows you to sidestep tedious replication and extract common display structures in shared templates. The
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# classic example is the use of a header and footer (even though the Action Pack-way would be to use Layouts):
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#
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# <%= render "shared/header" %>
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# Something really specific and terrific
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# <%= render "shared/footer" %>
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#
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# As you see, we use the output embeddings for the render methods. The render call itself will just return a string holding the
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# result of the rendering. The output embedding writes it to the current template.
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#
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# But you don't have to restrict yourself to static includes. Templates can share variables amongst themselves by using instance
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# variables defined using the regular embedding tags. Like this:
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#
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# <% @page_title = "A Wonderful Hello" %>
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# <%= render "shared/header" %>
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#
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# Now the header can pick up on the @page_title variable and use it for outputting a title tag:
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#
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# <title><%= @page_title %></title>
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#
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# == Passing local variables to sub templates
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#
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# You can pass local variables to sub templates by using a hash with the variable names as keys and the objects as values:
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#
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# <%= render "shared/header", { :headline => "Welcome", :person => person } %>
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#
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# These can now be accessed in shared/header with:
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#
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# Headline: <%= headline %>
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# First name: <%= person.first_name %>
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#
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# If you need to find out whether a certain local variable has been assigned a value in a particular render call,
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# you need to use the following pattern:
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#
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# <% if local_assigns.has_key? :headline %>
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# Headline: <%= headline %>
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# <% end %>
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#
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# Testing using <tt>defined? headline</tt> will not work. This is an implementation restriction.
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#
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# == Template caching
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#
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# By default, Rails will compile each template to a method in order to render it. When you alter a template, Rails will
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# check the file's modification time and recompile it.
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#
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# == Builder
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#
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# Builder templates are a more programmatic alternative to ERb. They are especially useful for generating XML content. An +XmlMarkup+ object
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# named +xml+ is automatically made available to templates with a +.rxml+ extension.
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#
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# Here are some basic examples:
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#
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# xml.em("emphasized") # => <em>emphasized</em>
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# xml.em { xml.b("emp & bold") } # => <em><b>emph & bold</b></em>
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# xml.a("A Link", "href"=>"http://onestepback.org") # => <a href="http://onestepback.org">A Link</a>
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# xml.target("name"=>"compile", "option"=>"fast") # => <target option="fast" name="compile"\>
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# # NOTE: order of attributes is not specified.
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#
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# Any method with a block will be treated as an XML markup tag with nested markup in the block. For example, the following:
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#
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# xml.div {
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# xml.h1(@person.name)
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# xml.p(@person.bio)
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# }
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#
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# would produce something like:
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#
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# <div>
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# <h1>David Heinemeier Hansson</h1>
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# <p>A product of Danish Design during the Winter of '79...</p>
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# </div>
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#
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# A full-length RSS example actually used on Basecamp:
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#
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# xml.rss("version" => "2.0", "xmlns:dc" => "http://purl.org/dc/elements/1.1/") do
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# xml.channel do
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# xml.title(@feed_title)
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# xml.link(@url)
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# xml.description "Basecamp: Recent items"
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# xml.language "en-us"
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# xml.ttl "40"
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#
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# for item in @recent_items
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# xml.item do
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# xml.title(item_title(item))
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# xml.description(item_description(item)) if item_description(item)
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# xml.pubDate(item_pubDate(item))
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# xml.guid(@person.firm.account.url + @recent_items.url(item))
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# xml.link(@person.firm.account.url + @recent_items.url(item))
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#
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# xml.tag!("dc:creator", item.author_name) if item_has_creator?(item)
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# end
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# end
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# end
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# end
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#
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# More builder documentation can be found at http://builder.rubyforge.org.
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#
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# == JavaScriptGenerator
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#
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# JavaScriptGenerator templates end in +.rjs+. Unlike conventional templates which are used to
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# render the results of an action, these templates generate instructions on how to modify an already rendered page. This makes it easy to
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# modify multiple elements on your page in one declarative Ajax response. Actions with these templates are called in the background with Ajax
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# and make updates to the page where the request originated from.
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#
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# 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.
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#
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# When an .rjs action is called with +link_to_remote+, the generated JavaScript is automatically evaluated. Example:
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#
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# link_to_remote :url => {:action => 'delete'}
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#
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# The subsequently rendered +delete.rjs+ might look like:
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#
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# page.replace_html 'sidebar', :partial => 'sidebar'
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# page.remove "person-#{@person.id}"
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# page.visual_effect :highlight, 'user-list'
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#
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# This refreshes the sidebar, removes a person element and highlights the user list.
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#
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# See the ActionView::Helpers::PrototypeHelper::GeneratorMethods documentation for more details.
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class Base
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include ERB::Util
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attr_reader :first_render
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attr_accessor :base_path, :assigns, :template_extension
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attr_accessor :controller
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attr_reader :logger, :response, :headers
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attr_internal *ActionController::Base::DEPRECATED_INSTANCE_VARIABLES
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# Specify trim mode for the ERB compiler. Defaults to '-'.
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# See ERb documentation for suitable values.
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@@erb_trim_mode = '-'
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cattr_accessor :erb_trim_mode
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# Specify whether file modification times should be checked to see if a template needs recompilation
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@@cache_template_loading = false
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cattr_accessor :cache_template_loading
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# Specify whether file extension lookup should be cached.
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# Should be +false+ for development environments. Defaults to +true+.
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@@cache_template_extensions = true
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cattr_accessor :cache_template_extensions
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# Specify whether local_assigns should be able to use string keys.
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# Defaults to +true+. String keys are deprecated and will be removed
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# shortly.
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@@local_assigns_support_string_keys = true
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cattr_accessor :local_assigns_support_string_keys
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# Specify whether RJS responses should be wrapped in a try/catch block
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# that alert()s the caught exception (and then re-raises it).
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@@debug_rjs = false
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cattr_accessor :debug_rjs
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@@template_handlers = HashWithIndifferentAccess.new
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module CompiledTemplates #:nodoc:
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# holds compiled template code
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end
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include CompiledTemplates
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# Maps inline templates to their method names
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@@method_names = {}
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# Map method names to their compile time
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@@compile_time = {}
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# Map method names to the names passed in local assigns so far
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@@template_args = {}
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# Count the number of inline templates
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@@inline_template_count = 0
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# Maps template paths without extension to their file extension returned by pick_template_extension.
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# If for a given path, path.ext1 and path.ext2 exist on the file system, the order of extensions
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# used by pick_template_extension determines whether ext1 or ext2 will be stored.
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@@cached_template_extension = {}
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class ObjectWrapper < Struct.new(:value) #:nodoc:
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end
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def self.load_helpers(helper_dir)#:nodoc:
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Dir.entries(helper_dir).sort.each do |helper_file|
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next unless helper_file =~ /^([a-z][a-z_]*_helper).rb$/
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require File.join(helper_dir, $1)
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helper_module_name = $1.camelize
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class_eval("include ActionView::Helpers::#{helper_module_name}") if Helpers.const_defined?(helper_module_name)
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end
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end
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# Register a class that knows how to handle template files with the given
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# extension. This can be used to implement new template types.
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# The constructor for the class must take the ActiveView::Base instance
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# as a parameter, and the class must implement a #render method that
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# takes the contents of the template to render as well as the Hash of
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# local assigns available to the template. The #render method ought to
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# return the rendered template as a string.
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def self.register_template_handler(extension, klass)
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@@template_handlers[extension] = klass
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end
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def initialize(base_path = nil, assigns_for_first_render = {}, controller = nil)#:nodoc:
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@base_path, @assigns = base_path, assigns_for_first_render
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@assigns_added = nil
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@controller = controller
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@logger = controller && controller.logger
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end
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# Renders the template present at <tt>template_path</tt>. If <tt>use_full_path</tt> is set to true,
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# it's relative to the template_root, otherwise it's absolute. The hash in <tt>local_assigns</tt>
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# is made available as local variables.
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def render_file(template_path, use_full_path = true, local_assigns = {}) #:nodoc:
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@first_render ||= template_path
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if use_full_path
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template_path_without_extension, template_extension = path_and_extension(template_path)
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if template_extension
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template_file_name = full_template_path(template_path_without_extension, template_extension)
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else
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template_extension = pick_template_extension(template_path).to_s
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template_file_name = full_template_path(template_path, template_extension)
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end
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else
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template_file_name = template_path
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template_extension = template_path.split('.').last
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end
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template_source = nil # Don't read the source until we know that it is required
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begin
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render_template(template_extension, template_source, template_file_name, local_assigns)
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rescue Exception => e
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if TemplateError === e
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e.sub_template_of(template_file_name)
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raise e
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else
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raise TemplateError.new(@base_path, template_file_name, @assigns, template_source, e)
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end
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end
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end
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# Renders the template present at <tt>template_path</tt> (relative to the template_root).
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# The hash in <tt>local_assigns</tt> is made available as local variables.
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def render(options = {}, old_local_assigns = {}, &block) #:nodoc:
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if options.is_a?(String)
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render_file(options, true, old_local_assigns)
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elsif options == :update
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update_page(&block)
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elsif options.is_a?(Hash)
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options[:locals] ||= {}
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options[:use_full_path] = options[:use_full_path].nil? ? true : options[:use_full_path]
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if options[:file]
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render_file(options[:file], options[:use_full_path], options[:locals])
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elsif options[:partial] && options[:collection]
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render_partial_collection(options[:partial], options[:collection], options[:spacer_template], options[:locals])
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elsif options[:partial]
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render_partial(options[:partial], ActionView::Base::ObjectWrapper.new(options[:object]), options[:locals])
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elsif options[:inline]
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render_template(options[:type] || :rhtml, options[:inline], nil, options[:locals] || {})
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end
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end
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end
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# Renders the +template+ which is given as a string as either rhtml or rxml depending on <tt>template_extension</tt>.
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# The hash in <tt>local_assigns</tt> is made available as local variables.
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def render_template(template_extension, template, file_path = nil, local_assigns = {}) #:nodoc:
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if handler = @@template_handlers[template_extension]
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template ||= read_template_file(file_path, template_extension) # Make sure that a lazyily-read template is loaded.
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delegate_render(handler, template, local_assigns)
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else
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compile_and_render_template(template_extension, template, file_path, local_assigns)
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end
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end
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# Render the provided template with the given local assigns. If the template has not been rendered with the provided
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# local assigns yet, or if the template has been updated on disk, then the template will be compiled to a method.
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#
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# Either, but not both, of template and file_path may be nil. If file_path is given, the template
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# will only be read if it has to be compiled.
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#
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def compile_and_render_template(extension, template = nil, file_path = nil, local_assigns = {}) #:nodoc:
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# convert string keys to symbols if requested
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local_assigns = local_assigns.symbolize_keys if @@local_assigns_support_string_keys
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# compile the given template, if necessary
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if compile_template?(template, file_path, local_assigns)
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template ||= read_template_file(file_path, extension)
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compile_template(extension, template, file_path, local_assigns)
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end
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# Get the method name for this template and run it
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method_name = @@method_names[file_path || template]
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evaluate_assigns
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send(method_name, local_assigns) do |*name|
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instance_variable_get "@content_for_#{name.first || 'layout'}"
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end
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end
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def pick_template_extension(template_path)#:nodoc:
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if @@cache_template_extensions
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@@cached_template_extension[template_path] ||= find_template_extension_for(template_path)
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else
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find_template_extension_for(template_path)
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end
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end
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def delegate_template_exists?(template_path)#:nodoc:
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@@template_handlers.find { |k,| template_exists?(template_path, k) }
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end
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def erb_template_exists?(template_path)#:nodoc:
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template_exists?(template_path, :rhtml)
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end
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def builder_template_exists?(template_path)#:nodoc:
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template_exists?(template_path, :rxml)
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end
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def javascript_template_exists?(template_path)#:nodoc:
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template_exists?(template_path, :rjs)
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end
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def file_exists?(template_path)#:nodoc:
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template_file_name, template_file_extension = path_and_extension(template_path)
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if template_file_extension
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template_exists?(template_file_name, template_file_extension)
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else
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cached_template_extension(template_path) ||
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%w(erb builder javascript delegate).any? do |template_type|
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send("#{template_type}_template_exists?", template_path)
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end
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end
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end
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# Returns true is the file may be rendered implicitly.
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def file_public?(template_path)#:nodoc:
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template_path.split('/').last[0,1] != '_'
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end
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private
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# Builds a string holding the full path of the template including extension
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def full_template_path(template_path, extension)
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"#{@base_path}/#{template_path}.#{extension}"
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end
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# Asserts the existence of a template.
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def template_exists?(template_path, extension)
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file_path = full_template_path(template_path, extension)
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@@method_names.has_key?(file_path) || FileTest.exists?(file_path)
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end
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def path_and_extension(template_path)
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template_path_without_extension = template_path.sub(/\.(\w+)$/, '')
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[ template_path_without_extension, $1 ]
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end
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def cached_template_extension(template_path)
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@@cache_template_extensions && @@cached_template_extension[template_path]
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end
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# Determines the template's file extension, such as rhtml, rxml, or rjs.
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def find_template_extension_for(template_path)
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if match = delegate_template_exists?(template_path)
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match.first.to_sym
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elsif erb_template_exists?(template_path): :rhtml
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elsif builder_template_exists?(template_path): :rxml
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elsif javascript_template_exists?(template_path): :rjs
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else
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raise ActionViewError, "No rhtml, rxml, rjs or delegate template found for #{template_path} in #{@base_path}"
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end
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end
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# This method reads a template file.
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def read_template_file(template_path, extension)
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File.read(template_path)
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end
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# Evaluate the local assigns and pushes them to the view.
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def evaluate_assigns
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unless @assigns_added
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assign_variables_from_controller
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@assigns_added = true
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end
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end
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def delegate_render(handler, template, local_assigns)
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handler.new(self).render(template, local_assigns)
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end
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# Assigns instance variables from the controller to the view.
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def assign_variables_from_controller
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@assigns.each { |key, value| instance_variable_set("@#{key}", value) }
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end
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# Return true if the given template was compiled for a superset of the keys in local_assigns
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def supports_local_assigns?(render_symbol, local_assigns)
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local_assigns.empty? ||
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((args = @@template_args[render_symbol]) && local_assigns.all? { |k,_| args.has_key?(k) })
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end
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# Method to check whether template compilation is necessary.
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# The template will be compiled if the inline template or file has not been compiled yet,
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# if local_assigns has a new key, which isn't supported by the compiled code yet,
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# or if the file has changed on disk and checking file mods hasn't been disabled.
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def compile_template?(template, file_name, local_assigns)
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method_key = file_name || template
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render_symbol = @@method_names[method_key]
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if @@compile_time[render_symbol] && supports_local_assigns?(render_symbol, local_assigns)
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if file_name && !@@cache_template_loading
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@@compile_time[render_symbol] < File.mtime(file_name) ||
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(File.symlink?(file_name) && (@@compile_time[render_symbol] < File.lstat(file_name).mtime))
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end
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else
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true
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end
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end
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# Method to create the source code for a given template.
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def create_template_source(extension, template, render_symbol, locals)
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if template_requires_setup?(extension)
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body = case extension.to_sym
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when :rxml
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"controller.response.content_type ||= 'application/xml'\n" +
|
|
"xml ||= Builder::XmlMarkup.new(:indent => 2)\n" +
|
|
template +
|
|
"\nxml.target!\n"
|
|
when :rjs
|
|
"controller.response.content_type ||= 'text/javascript'\n" +
|
|
"update_page do |page|\n#{template}\nend"
|
|
end
|
|
else
|
|
body = ERB.new(template, nil, @@erb_trim_mode).src
|
|
end
|
|
|
|
@@template_args[render_symbol] ||= {}
|
|
locals_keys = @@template_args[render_symbol].keys | locals
|
|
@@template_args[render_symbol] = locals_keys.inject({}) { |h, k| h[k] = true; h }
|
|
|
|
locals_code = ""
|
|
locals_keys.each do |key|
|
|
locals_code << "#{key} = local_assigns[:#{key}]\n"
|
|
end
|
|
|
|
"def #{render_symbol}(local_assigns)\n#{locals_code}#{body}\nend"
|
|
end
|
|
|
|
def template_requires_setup?(extension) #:nodoc:
|
|
templates_requiring_setup.include? extension.to_s
|
|
end
|
|
|
|
def templates_requiring_setup #:nodoc:
|
|
%w(rxml rjs)
|
|
end
|
|
|
|
def assign_method_name(extension, template, file_name)
|
|
method_key = file_name || template
|
|
@@method_names[method_key] ||= compiled_method_name(extension, template, file_name)
|
|
end
|
|
|
|
def compiled_method_name(extension, template, file_name)
|
|
['_run', extension, compiled_method_name_file_path_segment(file_name)].compact.join('_').to_sym
|
|
end
|
|
|
|
def compiled_method_name_file_path_segment(file_name)
|
|
if file_name
|
|
s = File.expand_path(file_name)
|
|
s.sub!(/^#{Regexp.escape(File.expand_path(RAILS_ROOT))}/, '') if defined?(RAILS_ROOT)
|
|
s.gsub!(/([^a-zA-Z0-9_])/) { $1[0].to_s }
|
|
s
|
|
else
|
|
(@@inline_template_count += 1).to_s
|
|
end
|
|
end
|
|
|
|
# Compile and evaluate the template's code
|
|
def compile_template(extension, template, file_name, local_assigns)
|
|
render_symbol = assign_method_name(extension, template, file_name)
|
|
render_source = create_template_source(extension, template, render_symbol, local_assigns.keys)
|
|
|
|
line_offset = @@template_args[render_symbol].size
|
|
if extension
|
|
case extension.to_sym
|
|
when :rxml, :rjs
|
|
line_offset += 2
|
|
end
|
|
end
|
|
|
|
begin
|
|
unless file_name.blank?
|
|
CompiledTemplates.module_eval(render_source, file_name, -line_offset)
|
|
else
|
|
CompiledTemplates.module_eval(render_source, 'compiled-template', -line_offset)
|
|
end
|
|
rescue Exception => e # errors from template code
|
|
if logger
|
|
logger.debug "ERROR: compiling #{render_symbol} RAISED #{e}"
|
|
logger.debug "Function body: #{render_source}"
|
|
logger.debug "Backtrace: #{e.backtrace.join("\n")}"
|
|
end
|
|
|
|
raise TemplateError.new(@base_path, file_name || template, @assigns, template, e)
|
|
end
|
|
|
|
@@compile_time[render_symbol] = Time.now
|
|
# logger.debug "Compiled template #{file_name || template}\n ==> #{render_symbol}" if logger
|
|
end
|
|
end
|
|
end
|
|
|
|
require 'action_view/template_error'
|