instance method `to_param`

Ruby on Rails 5.2.8.1

Since v3.2.22.5

Available in: v3.2.22.5 v4.0.13 v4.1.16 v4.2.9 v5.2.8.1 v6.0.6 v6.1.7.10 v7.0.10 v7.1.6 v7.2.3 v8.0.4 v8.1.2

Compare with:

to_param()

Returns a String, which Action Pack uses for constructing a 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/integration.rb, line 49
    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/integration.rb line 49 · View on GitHub · Improve this page · Find usages on GitHub

Defined in ActiveRecord::Integration

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