require 'active_support/core_ext/module' require 'action_controller/model_naming' module ActionController # The record identifier encapsulates a number of naming conventions for dealing with records, like Active Records or # pretty much any other model type that has an id. These patterns are then used to try elevate the view actions to # a higher logical level. # # # routes # resources :posts # # # view # <%= div_for(post) do %>
# <%= post.body %> What a wonderful world! # <% end %>
# # # controller # def update # post = Post.find(params[:id]) # post.update_attributes(params[:post]) # # redirect_to(post) # Calls polymorphic_url(post) which in turn calls post_url(post) # end # # As the example above shows, you can stop caring to a large extent what the actual id of the post is. # You just know that one is being assigned and that the subsequent calls in redirect_to expect that # same naming convention and allows you to write less code if you follow it. module RecordIdentifier extend self include ModelNaming JOIN = '_'.freeze NEW = 'new'.freeze # 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 protected # 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) key = convert_to_model(record).to_key key ? key.join('_') : key end end end