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Diffstat (limited to 'actionpack/lib/action_view/lookup_context.rb')
| -rw-r--r-- | actionpack/lib/action_view/lookup_context.rb | 154 |
1 files changed, 154 insertions, 0 deletions
diff --git a/actionpack/lib/action_view/lookup_context.rb b/actionpack/lib/action_view/lookup_context.rb new file mode 100644 index 0000000000..27ee8b23c9 --- /dev/null +++ b/actionpack/lib/action_view/lookup_context.rb @@ -0,0 +1,154 @@ +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) + #{"value << nil unless value.include?(nil)" unless options[:allow_nil] == false} + + 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: + attr_reader :details + alias :eql? :equal? + + @details_keys = Hash.new + + def self.get(details) + @details_keys[details] ||= new(details) + end + + def initialize(details) + @details, @hash = details, details.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(name, prefix, partial, details, details_key) + end + + def find_all(name, prefix = nil, partial = false) + @view_paths.find_all(name, prefix, partial, details, details_key) + end + + def exists?(name, prefix = nil, partial = false) + @view_paths.exists?(name, prefix, partial, details, details_key) + end + + # 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 + 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, freeze=true) + 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
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