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require 'thread_safe'
module ActionView
class DependencyTracker # :nodoc:
@trackers = ThreadSafe::Cache.new
def self.find_dependencies(name, template)
tracker = @trackers[template.handler]
if tracker.present?
tracker.call(name, template)
else
[]
end
end
def self.register_tracker(extension, tracker)
handler = Template.handler_for_extension(extension)
@trackers[handler] = tracker
end
def self.remove_tracker(handler)
@trackers.delete(handler)
end
class ERBTracker # :nodoc:
EXPLICIT_DEPENDENCY = /# Template Dependency: (\S+)/
# A valid ruby identifier - suitable for class, method and specially variable names
IDENTIFIER = /
[[:alpha:]_] # at least one uppercase letter, lowercase letter or underscore
[[:word:]]* # followed by optional letters, numbers or underscores
/x
# Any kind of variable name. e.g. @instance, @@class, $global or local.
# Possibly following a method call chain
VARIABLE_OR_METHOD_CHAIN = /
(?:\$|@{1,2})? # optional global, instance or class variable indicator
(?:#{IDENTIFIER}\.)* # followed by an optional chain of zero-argument method calls
(?<dynamic>#{IDENTIFIER}) # and a final valid identifier, captured as DYNAMIC
/x
# A simple string literal. e.g. "School's out!"
STRING = /
(?<quote>['"]) # an opening quote
(?<static>.*?) # with anything inside, captured as STATIC
\k<quote> # and a matching closing quote
/x
# Part of any hash containing the :partial key
PARTIAL_HASH_KEY = /
(?:\bpartial:|:partial\s*=>) # partial key in either old or new style hash syntax
\s* # followed by optional spaces
/x
# Matches:
# partial: "comments/comment", collection: @all_comments => "comments/comment"
# (object: @single_comment, partial: "comments/comment") => "comments/comment"
#
# "comments/comments"
# 'comments/comments'
# ('comments/comments')
#
# (@topic) => "topics/topic"
# topics => "topics/topic"
# (message.topics) => "topics/topic"
RENDER_ARGUMENTS = /\A
(?:\s*\(?\s*) # optional opening paren surrounded by spaces
(?:.*?#{PARTIAL_HASH_KEY})? # optional hash, up to the partial key declaration
(?:#{STRING}|#{VARIABLE_OR_METHOD_CHAIN}) # finally, the dependency name of interest
/xm
def self.call(name, template)
new(name, template).dependencies
end
def initialize(name, template)
@name, @template = name, template
end
def dependencies
render_dependencies + explicit_dependencies
end
attr_reader :name, :template
private :name, :template
private
def source
template.source
end
def directory
name.split("/")[0..-2].join("/")
end
def render_dependencies
render_dependencies = []
render_calls = source.split(/\brender\b/).drop(1)
render_calls.each do |arguments|
arguments.scan(RENDER_ARGUMENTS) do
add_dynamic_dependency(render_dependencies, Regexp.last_match[:dynamic])
add_static_dependency(render_dependencies, Regexp.last_match[:static])
end
end
render_dependencies.uniq
end
def add_dynamic_dependency(dependencies, dependency)
if dependency
dependencies << "#{dependency.pluralize}/#{dependency.singularize}"
end
end
def add_static_dependency(dependencies, dependency)
if dependency
if dependency.include?('/')
dependencies << dependency
else
dependencies << "#{directory}/#{dependency}"
end
end
end
def explicit_dependencies
source.scan(EXPLICIT_DEPENDENCY).flatten.uniq
end
end
register_tracker :erb, ERBTracker
end
end