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April 7, 2011 09:59
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require 'active_support/core_ext/array/wrap' | |
require 'active_support/core_ext/object/blank' | |
module ActionView | |
# = Action View Lookup Context | |
# | |
# LookupContext is the object responsible to hold all information required to lookup | |
# templates, i.e. view paths and details. The LookupContext is also responsible to | |
# generate a key, given to view paths, used in the resolver cache lookup. Since | |
# this key is generated just once during the request, it speeds up all cache accesses. | |
class LookupContext #:nodoc: | |
mattr_accessor :fallbacks | |
@@fallbacks = FallbackFileSystemResolver.instances | |
mattr_accessor :registered_details | |
self.registered_details = [] | |
mattr_accessor :registered_detail_setters | |
self.registered_detail_setters = [] | |
def self.register_detail(name, options = {}, &block) | |
self.registered_details << name | |
self.registered_detail_setters << [name, "#{name}="] | |
Accessors.send :define_method, :"_#{name}_defaults", &block | |
Accessors.module_eval <<-METHOD, __FILE__, __LINE__ + 1 | |
def #{name} | |
@details[:#{name}] | |
end | |
protected | |
def #{name}=(value) | |
value = Array.wrap(value.presence || _#{name}_defaults) | |
_set_detail(:#{name}, value) if value != @details[:#{name}] | |
end | |
METHOD | |
end | |
# Holds accessors for the registered details. | |
module Accessors #:nodoc: | |
end | |
register_detail(:formats) { Mime::SET.symbols } | |
register_detail(:locale) { [I18n.locale, I18n.default_locale] } | |
class DetailsKey #:nodoc: | |
alias :eql? :equal? | |
alias :object_hash :hash | |
attr_reader :hash | |
@details_keys = Hash.new | |
def self.get(details) | |
@details_keys[details.freeze] ||= new | |
end | |
def initialize | |
@hash = object_hash | |
end | |
end | |
def initialize(view_paths, details = {}) | |
@details, @details_key = { :handlers => default_handlers }, nil | |
@frozen_formats, @skip_default_locale = false, false | |
@cache = true | |
@details[:locale] ||= I18n.locale | |
self.view_paths = view_paths | |
self.registered_detail_setters.each do |key, setter| | |
send(setter, details[key]) | |
end | |
end | |
module ViewPaths | |
attr_reader :view_paths | |
# Whenever setting view paths, makes a copy so we can manipulate then in | |
# instance objects as we wish. | |
def view_paths=(paths) | |
@view_paths = ActionView::Base.process_view_paths(paths) | |
end | |
def find(name, prefixes = [], partial = false, keys = []) | |
@view_paths.find(*args_for_lookup(name, prefixes, partial, keys)) | |
end | |
alias :find_template :find | |
def find_all(name, prefixes = [], partial = false, keys = []) | |
@view_paths.find_all(*args_for_lookup(name, prefixes, partial, keys)) | |
end | |
def exists?(name, prefixes = [], partial = false, keys = []) | |
@view_paths.exists?(*args_for_lookup(name, prefixes, partial, keys)) | |
end | |
alias :template_exists? :exists? | |
# Add fallbacks to the view paths. Useful in cases you are rendering a :file. | |
def with_fallbacks | |
added_resolvers = 0 | |
self.class.fallbacks.each do |resolver| | |
next if view_paths.include?(resolver) | |
view_paths.push(resolver) | |
added_resolvers += 1 | |
end | |
yield | |
ensure | |
added_resolvers.times { view_paths.pop } | |
end | |
protected | |
def args_for_lookup(name, prefixes, partial, keys) #:nodoc: | |
name, prefixes = normalize_name(name, prefixes) | |
[name, prefixes, partial || false, @details, details_key, keys] | |
end | |
# Support legacy foo.erb names even though we now ignore .erb | |
# as well as incorrectly putting part of the path in the template | |
# name instead of the prefix. | |
def normalize_name(name, prefixes) #:nodoc: | |
name = name.to_s.gsub(handlers_regexp, '') | |
parts = name.split('/') | |
name = parts.pop | |
prefixes = if prefixes.blank? | |
[parts.join('/')] | |
else | |
prefixes.map { |prefix| [prefix, *parts].compact.join('/') } | |
end | |
return name, prefixes | |
end | |
def default_handlers #:nodoc: | |
@@default_handlers ||= Template::Handlers.extensions | |
end | |
def handlers_regexp #:nodoc: | |
@@handlers_regexp ||= /\.(?:#{default_handlers.join('|')})$/ | |
end | |
end | |
module Details | |
attr_accessor :cache | |
# Calculate the details key. Remove the handlers from calculation to improve performance | |
# since the user cannot modify it explicitly. | |
def details_key #:nodoc: | |
@details_key ||= DetailsKey.get(@details) if @cache | |
end | |
# Temporary skip passing the details_key forward. | |
def disable_cache | |
old_value, @cache = @cache, false | |
yield | |
ensure | |
@cache = old_value | |
end | |
# Freeze the current formats in the lookup context. By freezing them, you are guaranteeing | |
# that next template lookups are not going to modify the formats. The controller can also | |
# use this, to ensure that formats won't be further modified (as it does in respond_to blocks). | |
def freeze_formats(formats, unless_frozen=false) #:nodoc: | |
return if unless_frozen && @frozen_formats | |
self.formats = formats | |
@frozen_formats = true | |
end | |
# Overload formats= to reject ["*/*"] values. | |
def formats=(values) | |
if values && values.size == 1 | |
value = values.first | |
values = nil if value == "*/*" | |
values << :html if value == :js | |
end | |
super(values) | |
end | |
# Do not use the default locale on template lookup. | |
def skip_default_locale! | |
@skip_default_locale = true | |
self.locale = nil | |
end | |
# Overload locale to return a symbol instead of array. | |
def locale | |
@details[:locale].first | |
end | |
# Overload locale= to also set the I18n.locale. If the current I18n.config object responds | |
# to original_config, it means that it's has a copy of the original I18n configuration and it's | |
# acting as proxy, which we need to skip. | |
def locale=(value) | |
config = I18n.config.respond_to?(:original_config) ? I18n.config.original_config : I18n.config | |
config.locale = value | |
super(@skip_default_locale ? I18n.locale : _locale_defaults) | |
end | |
# A method which only uses the first format in the formats array for layout lookup. | |
# This method plays straight with instance variables for performance reasons. | |
def with_layout_format | |
if formats.size == 1 | |
yield | |
else | |
old_formats = formats | |
_set_detail(:formats, formats[0,1]) | |
begin | |
yield | |
ensure | |
_set_detail(:formats, old_formats) | |
end | |
end | |
end | |
# Update the details keys by merging the given hash into the current | |
# details hash. If a block is given, the details are modified just during | |
# the execution of the block and reverted to the previous value after. | |
def update_details(new_details) | |
old_details = @details.dup | |
registered_detail_setters.each do |key, setter| | |
send(setter, new_details[key]) if new_details.key?(key) | |
end | |
begin | |
yield | |
ensure | |
@details_key = nil | |
@details = old_details | |
end | |
end | |
protected | |
def _set_detail(key, value) | |
@details_key = nil | |
@details = @details.dup if @details.frozen? | |
@details[key] = value.freeze | |
end | |
end | |
include Accessors | |
include Details | |
include ViewPaths | |
end | |
end |
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