Module: ActionView::RecordIdentifier
Relationships & Source Files | |
Extension / Inclusion / Inheritance Descendants | |
Included In:
| |
Defined in: | actionview/lib/action_view/record_identifier.rb |
Overview
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_post"
dom_class(Post) # => "post"
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
Constant Summary
Instance Method Summary
-
#dom_class(record_or_class, prefix = nil)
The DOM class convention is to use the singular form of an object or class.
-
#dom_id(record_or_class, prefix = nil)
The DOM id convention is to use the singular form of an object or class with the id following an underscore.
-
#record_key_for_dom_id(record)
private
Returns a string representation of the key attribute(s) that is suitable for use in an HTML DOM id.
Instance Method Details
#dom_class(record_or_class, prefix = nil)
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"
# File 'actionview/lib/action_view/record_identifier.rb', line 78
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
#dom_id(record_or_class, prefix = nil)
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_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, :custom) # => "custom_post"
# File 'actionview/lib/action_view/record_identifier.rb', line 93
def dom_id(record_or_class, prefix = nil) raise ArgumentError, "dom_id must be passed a record_or_class as the first argument, you passed #{record_or_class.inspect}" unless record_or_class record_id = record_key_for_dom_id(record_or_class) unless record_or_class.is_a?(Class) if record_id "#{dom_class(record_or_class, prefix)}#{JOIN}#{record_id}" else dom_class(record_or_class, prefix || NEW) end end
#record_key_for_dom_id(record) (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 override this method.
# File 'actionview/lib/action_view/record_identifier.rb', line 113
def record_key_for_dom_id(record) # :doc: key = convert_to_model(record).to_key key && key.all? ? key.join(JOIN) : nil end