instance method to_param

Ruby on Rails 3.1.12

Since v2.2.3 Last seen in v3.1.12

Available in: v2.2.3 v2.3.18 v3.0.20 v3.1.12

Signature

to_param()

Returns a String, which Action Pack uses for constructing an URL to this object. The default implementation returns this record’s id as a String, or nil if this record’s unsaved.

For example, suppose that you have a User model, and that you have a resources :users route. Normally, user_path will construct a path with the user object’s ‘id’ in it:

user = User.find_by_name('Phusion')
user_path(user)  # => "/users/1"

You can override to_param in your model to make user_path construct a path using the user’s name instead of the user’s id:

class User < ActiveRecord::Base
  def to_param  # overridden
    name
  end
end

user = User.find_by_name('Phusion')
user_path(user)  # => "/users/Phusion"
Source
# File activerecord/lib/active_record/base.rb, line 1649
      def to_param
        # We can't use alias_method here, because method 'id' optimizes itself on the fly.
        id && id.to_s # Be sure to stringify the id for routes
      end

Defined in activerecord/lib/active_record/base.rb line 1649 · View on GitHub · Improve this page · Find usages on GitHub

Defined in ActiveRecord::Base

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