Returns a list of helper names in a given path.

ActionController::Base.all_helpers_from_path 'app/helpers'
# => ["application", "chart", "rubygems"]

Source: on GitHub

# File actionpack/lib/abstract_controller/helpers.rb, line 93
 

Source: | on GitHub

# File actionpack/lib/abstract_controller/helpers.rb, line 218
def _helpers_for_modification
 unless @_helpers
 self._helpers = define_helpers_module(self, superclass._helpers)
 end
 _helpers
end

Clears up all existing helpers in this class, only keeping the helper with the same name as this class.

Source: | on GitHub

# File actionpack/lib/abstract_controller/helpers.rb, line 209
def clear_helpers
 inherited_helper_methods = _helper_methods
 self._helpers = Module.new
 self._helper_methods = Array.new
 inherited_helper_methods.each { |meth| helper_method meth }
 default_helper_module! unless anonymous?
end

Includes the given modules in the template class.

Modules can be specified in different ways. All of the following calls include FooHelper:

# Module, recommended.
helper FooHelper
# String/symbol without the "helper" suffix, camel or snake case.
helper "Foo"
helper :Foo
helper "foo"
helper :foo

The last two assume that "foo".camelize returns "Foo".

When strings or symbols are passed, the method finds the actual module object using String#constantize. Therefore, if the module has not been yet loaded, it has to be autoloadable, which is normally the case.

Namespaces are supported. The following calls include Foo::BarHelper:

# Module, recommended.
helper Foo::BarHelper
# String/symbol without the "helper" suffix, camel or snake case.
helper "Foo::Bar"
helper :"Foo::Bar"
helper "foo/bar"
helper :"foo/bar"

The last two assume that "foo/bar".camelize returns "Foo::Bar".

The method accepts a block too. If present, the block is evaluated in the context of the controller helper module. This simple call makes the wadus method available in templates of the enclosing controller:

helper do
 def wadus
 "wadus"
 end
end

Furthermore, all the above styles can be mixed together:

helper FooHelper, "woo", "bar/baz" do
 def wadus
 "wadus"
 end
end

Source: | on GitHub

# File actionpack/lib/abstract_controller/helpers.rb, line 198
def helper(*args, &block)
 modules_for_helpers(args).each do |mod|
 next if _helpers.include?(mod)
 _helpers_for_modification.include(mod)
 end
 _helpers_for_modification.module_eval(&block) if block_given?
end

Declare a controller method as a helper. For example, the following makes the current_user and logged_in? controller methods available to the view:

class ApplicationController < ActionController::Base
 helper_method :current_user, :logged_in?
 private
 def current_user
 @current_user ||= User.find_by(id: session[:user])
 end
 def logged_in?
 current_user != nil
 end
end

In a view:

<% if logged_in? -%>Welcome, <%= current_user.name %><% end -%>

Parameters

• method[, method] - A name or names of a method on the controller to be made available on the view.

Source: | on GitHub

# File actionpack/lib/abstract_controller/helpers.rb, line 128
 def helper_method(*methods)
 methods.flatten!
 self._helper_methods += methods
 location = caller_locations(1, 1).first
 file, line = location.path, location.lineno
 methods.each do |method|
 # def current_user(...)
 # controller.send(:'current_user', ...)
 # end
 _helpers_for_modification.class_eval <<~ruby_eval.lines.map(&:strip).join(";"), file, line
 def #{method}(...)
 controller.send(:'#{method}', ...)
 end
 ruby_eval
 end
 end

When a class is inherited, wrap its helper module in a new module. This ensures that the parent class’s module can be changed independently of the child class’s.

Source: | on GitHub

# File actionpack/lib/abstract_controller/helpers.rb, line 68
def inherited(klass)
 # Inherited from parent by default
 klass._helpers = nil
 klass.class_eval { default_helper_module! } unless klass.anonymous?
 super
end

Given an array of values like the ones accepted by helper, this method returns an array with the corresponding modules, in the same order.

ActionController::Base.modules_for_helpers(["application", "chart", "rubygems"])
# => [ApplicationHelper, ChartHelper, RubygemsHelper]

Source: on GitHub

# File actionpack/lib/abstract_controller/helpers.rb, line 81