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Diffstat (limited to 'actionview/lib/action_view/record_identifier.rb')
| -rw-r--r-- | actionview/lib/action_view/record_identifier.rb | 112 |
1 files changed, 112 insertions, 0 deletions
diff --git a/actionview/lib/action_view/record_identifier.rb b/actionview/lib/action_view/record_identifier.rb new file mode 100644 index 0000000000..ee39b6050d --- /dev/null +++ b/actionview/lib/action_view/record_identifier.rb @@ -0,0 +1,112 @@ +# frozen_string_literal: true + +require "active_support/core_ext/module" +require "action_view/model_naming" + +module ActionView + # RecordIdentifier encapsulates methods used by various ActionView helpers + # to associate records with DOM elements. + # + # Consider for example the following code that form of post: + # + # <%= form_for(post) do |f| %> + # <%= f.text_field :body %> + # <% end %> + # + # When +post+ is a new, unsaved ActiveRecord::Base instance, the resulting HTML + # is: + # + # <form class="new_post" id="new_post" action="/posts" accept-charset="UTF-8" method="post"> + # <input type="text" name="post[body]" id="post_body" /> + # </form> + # + # When +post+ is a persisted ActiveRecord::Base instance, the resulting HTML + # is: + # + # <form class="edit_post" id="edit_post_42" action="/posts/42" accept-charset="UTF-8" method="post"> + # <input type="text" value="What a wonderful world!" name="post[body]" id="post_body" /> + # </form> + # + # In both cases, the +id+ and +class+ of the wrapping DOM element are + # automatically generated, following naming conventions encapsulated by the + # RecordIdentifier methods #dom_id and #dom_class: + # + # dom_id(Post.new) # => "new_post" + # dom_class(Post.new) # => "post" + # dom_id(Post.find 42) # => "post_42" + # dom_class(Post.find 42) # => "post" + # + # Note that these methods do not strictly require +Post+ to be a subclass of + # ActiveRecord::Base. + # Any +Post+ class will work as long as its instances respond to +to_key+ + # and +model_name+, given that +model_name+ responds to +param_key+. + # For instance: + # + # class Post + # attr_accessor :to_key + # + # def model_name + # OpenStruct.new param_key: 'post' + # end + # + # def self.find(id) + # new.tap { |post| post.to_key = [id] } + # end + # end + module RecordIdentifier + extend self + extend ModelNaming + + include ModelNaming + + JOIN = "_" + NEW = "new" + + # The DOM class convention is to use the singular form of an object or class. + # + # dom_class(post) # => "post" + # dom_class(Person) # => "person" + # + # If you need to address multiple instances of the same class in the same view, you can prefix the dom_class: + # + # dom_class(post, :edit) # => "edit_post" + # dom_class(Person, :edit) # => "edit_person" + def dom_class(record_or_class, prefix = nil) + singular = model_name_from_record_or_class(record_or_class).param_key + prefix ? "#{prefix}#{JOIN}#{singular}" : singular + end + + # The DOM id convention is to use the singular form of an object or class with the id following an underscore. + # If no id is found, prefix with "new_" instead. + # + # dom_id(Post.find(45)) # => "post_45" + # dom_id(Post.new) # => "new_post" + # + # If you need to address multiple instances of the same class in the same view, you can prefix the dom_id: + # + # dom_id(Post.find(45), :edit) # => "edit_post_45" + # dom_id(Post.new, :custom) # => "custom_post" + def dom_id(record, prefix = nil) + if record_id = record_key_for_dom_id(record) + "#{dom_class(record, prefix)}#{JOIN}#{record_id}" + else + dom_class(record, prefix || NEW) + end + end + + private + + # Returns a string representation of the key attribute(s) that is suitable for use in an HTML DOM id. + # This can be overwritten to customize the default generated string representation if desired. + # If you need to read back a key from a dom_id in order to query for the underlying database record, + # you should write a helper like 'person_record_from_dom_id' that will extract the key either based + # on the default implementation (which just joins all key attributes with '_') or on your own + # overwritten version of the method. By default, this implementation passes the key string through a + # method that replaces all characters that are invalid inside DOM ids, with valid ones. You need to + # make sure yourself that your dom ids are valid, in case you overwrite this method. + def record_key_for_dom_id(record) # :doc: + key = convert_to_model(record).to_key + key ? key.join(JOIN) : key + end + end +end |