require 'active_support/core_ext/object/try'
require 'active_support/core_ext/object/blank'
module ActionView
# 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 = [FileSystemResolver.new(""), FileSystemResolver.new("/")]
mattr_accessor :registered_details
self.registered_details = []
def self.register_detail(name, options = {}, &block)
self.registered_details << name
Setters.send :define_method, :"_#{name}_defaults", &block
Setters.module_eval <<-METHOD, __FILE__, __LINE__ + 1
def #{name}=(value)
value = Array(value.presence || _#{name}_defaults)
unless value == @details[:#{name}]
@details_key, @details = nil, @details.merge(:#{name} => value)
@details.freeze
end
end
METHOD
end
# Holds raw setters for the registered details.
module Setters #:nodoc:
end
register_detail(:formats) { Mime::SET.symbols }
register_detail(:locale) { [I18n.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] ||= new
end
def initialize
@hash = object_hash
end
end
def initialize(view_paths, details = {})
@details, @details_key = {}, nil
self.view_paths = view_paths
self.details = details
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, prefix = nil, partial = false)
@view_paths.find(*args_for_lookup(name, prefix, partial))
end
alias :find_template :find
def find_all(name, prefix = nil, partial = false)
@view_paths.find_all(*args_for_lookup(name, prefix, partial))
end
def exists?(name, prefix = nil, partial = false)
@view_paths.exists?(*args_for_lookup(name, prefix, partial))
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, prefix, partial) #:nodoc:
name, prefix = normalize_name(name, prefix)
details_key = self.details_key
details = self.details.merge(:handlers => default_handlers)
[name, prefix, partial || false, details, details_key]
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, prefix) #:nodoc:
name = name.to_s.gsub(handlers_regexp, '')
parts = name.split('/')
return parts.pop, [prefix, *parts].compact.join("/")
end
def default_handlers #:nodoc:
@detault_handlers ||= Template::Handlers.extensions
end
def handlers_regexp #:nodoc:
@handlers_regexp ||= /\.(?:#{default_handlers.join('|')})$/
end
end
module Details
attr_reader :details
def details=(given_details)
registered_details.each { |key| send(:"#{key}=", given_details[key]) }
end
def details_key
@details_key ||= DetailsKey.get(@details)
end
# Shortcut to read formats from details.
def formats
@details[:formats].compact
end
# Overload formats= to reject [:"*/*"] values.
def formats=(value)
value = nil if value == [:"*/*"]
super(value)
end
# Shortcut to read locale.
def locale
I18n.locale
end
# Overload locale= to also set the I18n.locale. If the current I18n.config object responds
# to i18n_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)
value = value.first if value.is_a?(Array)
config = I18n.config.respond_to?(:i18n_config) ? I18n.config.i18n_config : I18n.config
config.locale = value if value
super(I18n.locale)
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
self.details = old_details.merge(new_details)
if block_given?
begin
yield
ensure
@details = old_details
end
end
end
end
include Setters
include Details
include ViewPaths
end
end