I would like to extend the MessageDelivery class in the ActionMailer module and am not successful in my attempts.
From what I have read, it should be as simple as:
module ActionMailer
class MessageDelivery
def deliver_at_next_time_interval
.. my code here
end
end
end
I have tried any number of variations on this and nothing seems to work - the method is never found when called from an object with the class ActionMailer::MessageDelivery. From what I understand, it shouldn't matter where my extension resides and I have it under app/mailers.
Any suggestions on what should work?
Related
I have a small problem that I can't quite get my head around. Since I want to reuse a lot of the methods defined in my Class i decided to put them into an Helper, which I can easily include whenever needed. The basic Class looks like this:
class MyClass
include Helper::MyHelper
def self.do_something input
helper_method(input)
end
end
And here is the Helper:
module Helper
module MyHelper
def helper_method input
input.titleize
end
end
end
Right now I can't call "helper_method" from my Class because of what I think is a scope issue? What am I doing wrong?
I guess that is because self pointer inside of do_something input is InternshipInputFormatter, and not the instance of InternshipInputFormatter. so proper alias to call helper_method(input) will be self.helper_method(input), however you have included the Helper::MyHelper into the InternshipInputFormatter class as an instance methods, not a singleton, so try to extend the class with the instance methods of the module as the signelton methods for the class:
class InternshipInputFormatter
extend Helper::MyHelper
def self.do_something input
helper_method(input)
end
end
InternshipInputFormatter.do_something 1
# NoMethodError: undefined method `titleize' for 1:Fixnum
As you can see, the call has stopped the execution inside the helper_method. Please refer to the document to see the detailed difference between include, and extend.
I have a module called Sms that I'm defining in lib/sms.rb. Within it, I have a method called Sms.chunk that uses the method word_wrap. This is part of the TextHelper library, so I am including it at the beginning of the module with include ActionView::Helpers::TextHelper:
module Sms
include ActionView::Helpers::TextHelper
def Sms.chunk
...
word_wrap
...
I am requiring this module during initialization with the line require "sms" in config/initializers/additional_libs.rb
I also have a Grape API class called TWILIO_API where I want to call Sms.chunk. However, when I do, I get undefined methodword_wrap' for Sms:Module`. I have tried including the TextHelper library in the TWILIO_API class itself, and various other ways of including it, but have had no success.
What am I doing wrong here?
The problem is that wrap_word is an instance method , and you're invoking it from a class method Sms.chunk. Make it an instance method by dropping the Sms. part. For instance, the following works:
require 'action_view'
class Test
include ActionView::Helpers::TextHelper
def test_method
word_wrap('Once upon a time')
end
end
o = Test.new
p o.test_method # "Once upon a time"
I'm writing a script for my rails application and I'm trying to format the numbers with delimeters so they're easier to read. But I have a problem in calling the number_with_delimeter method from ActionView::Helpers::NumberHelpers
I tried
class MyClass < ActiveRecord::base
extend ActiveView::Helpers::NumberHelper
def self.run
puts "#{number_with_delimeter(1234567)}"
end
end
MyClass.run
but it just doesn't work. I always get undefined method errors. I tried it with include instead of extend and some other variations. None of them worked. I don't know how to proceed.
Is there any way to call this method in a script?
*Note: * I call the script with rails r script/my_script.rb
An elegant solution consists in delegation:
def self.run
puts "#{helper.number_with_delimiter(1234567)}"
end
def self.helper
Helper.instance
end
class Helper
include Singleton
include ActionView::Helpers::NumberHelper
end
Sidenotes:
including modules overloads your class
including the helpers didn't help because you were working at the class level.
formatting should not be model's job, you should extract this kind of logic within presenters.
I'm trying to extend a specific model in my app using railtie. Adding class methods works, but neither does instance methods. I have the following code:
class Railtie
def self.insert
return unless defined?(::ActiveRecord)
::MyApp::MyModel.extend(ModelMethods)
end
end
module ModelMethods
def hello
puts "hello"
end
end
Now, I'm able to call MyModel.hello. But what should I do if i want to add some instance methods? When I try to add them through ::MyApp::MyModel.include(InstanceMethods) it fails with something saying calling a private methods.
include is a private method and cannot have an explicit receiver. You can get around this limitation by using send:
MyModel.send(:include, InstanceMethods)
Ok so I am using some module/lib/plugin (not sure of the exact name), let's say its a authentication/authorization plugin like: http://github.com/technoweenie/restful-authentication
class HomeController < ApplicationController
some_module_name_here
end
Now just from adding the code above 'some_module_name_here', I can access to methods from that module.
What is that line of code doing that gives me access to methods/objects from the module?
Is that declaring a variable like in say java/c#:
public SomeModule _someModule;
I know that plugins/modules basically extend the class under the covers, but how does it do this with a single line of code?
Is it called in the constructor somehow?
When you create a ruby plugin, and load it into the rails app via environment.rb, bundler, or a require call, the methods are loaded as "modules" that can be called. The ones that act like you're talking about will have an extra method called acts_as_list or something similar. All that method does is include the methods of the module into the class where that line was called.
Here's an example, which you could include in your app's lib folder and play with:
module Bellmyer
module Pointless
def self.included(base)
base.extend PointlessMethods
end
module PointlessMethods
def acts_as_pointless
unless included_modules.include? InstanceMethods
extend ClassMethods
include InstanceMethods
end
end
end
module ClassMethods
def pointless_class?
true
end
end
module InstanceMethods
def pointless_instance?
true
end
end
end
end
The module is available to any ruby class in your app, but the methods don't actually get loaded until you call acts_as_pointless, which then includes and extends your class with the methods listed. Only the acts_as_pointless method is immediately available to the model. This is the standard pattern for an ActiveRecord plugin.
That's not how it works.
When the plugin or gem is loaded it adds a class method to, in this case, ApplicationController named some_module_name. When you call that methods, a bunch of other class and instance methods are included.
Check out your favourite gem or plugin to see how they do it exactly.