Method: ActionDispatch::Routing::Mapper::Base#mount

Defined in:
lib/action_dispatch/routing/mapper.rb

#mount(app = nil, deprecated_options = nil, as: DEFAULT, via: nil, at: nil, defaults: nil, constraints: nil, anchor: false, format: false, path: nil, internal: nil, **mapping, &block) ⇒ Object

Mount a Rack-based application to be used within the application.

mount SomeRackApp, at: "some_route"

For options, see match, as mount uses it internally.

All mounted applications come with routing helpers to access them. These are named after the class specified, so for the above example the helper is either some_rack_app_path or some_rack_app_url. To customize this helper’s name, use the :as option:

mount(SomeRackApp, at: "some_route", as: "exciting")

This will generate the exciting_path and exciting_url helpers which can be used to navigate to this mounted app.

Raises:

  • (ArgumentError) 


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# File 'lib/action_dispatch/routing/mapper.rb', line 605

def mount(app = nil, deprecated_options = nil, as: DEFAULT, via: nil, at: nil, defaults: nil, constraints: nil, anchor: false, format: false, path: nil, internal: nil, **mapping, &block)
  if deprecated_options.is_a?(Hash)
    as = assign_deprecated_option(deprecated_options, :as, :mount) if deprecated_options.key?(:as)
    via ||= assign_deprecated_option(deprecated_options, :via, :mount)
    at ||= assign_deprecated_option(deprecated_options, :at, :mount)
    defaults ||= assign_deprecated_option(deprecated_options, :defaults, :mount)
    constraints ||= assign_deprecated_option(deprecated_options, :constraints, :mount)
    anchor = assign_deprecated_option(deprecated_options, :anchor, :mount) if deprecated_options.key?(:anchor)
    format = assign_deprecated_option(deprecated_options, :format, :mount) if deprecated_options.key?(:format)
    path ||= assign_deprecated_option(deprecated_options, :path, :mount)
    internal ||= assign_deprecated_option(deprecated_options, :internal, :mount)
    assign_deprecated_options(deprecated_options, mapping, :mount)
  end

  path_or_action = at

  if app.nil?
    hash_app, hash_path = mapping.find { |key, _| key.respond_to?(:call) }
    mapping.delete(hash_app) if hash_app

    app ||= hash_app
    path_or_action ||= hash_path
  end

  raise ArgumentError, "A rack application must be specified" unless app.respond_to?(:call)
  raise ArgumentError, "    Must be called with mount point\n\n      mount SomeRackApp, at: \"some_route\"\n      or\n      mount(SomeRackApp => \"some_route\")\n  MSG\n\n  rails_app = rails_app? app\n  as = app_name(app, rails_app) if as == DEFAULT\n\n  target_as = name_for_action(as, path_or_action)\n  via ||= :all\n\n  match(path_or_action, to: app, as:, via:, defaults:, constraints:, anchor:, format:, path:, internal:, **mapping, &block)\n\n  define_generate_prefix(app, target_as) if rails_app\n  self\nend\n" unless path_or_action