How to Create a Custom Method for the Rails Console

How to create a custom method for the rails console?

Just put it in the ~/.irbrc file. It gets loaded every time you run irb or rails console. The Rails console is just irb with your Rails application environment loaded.

Find more infos about irb here: http://ruby-doc.com/docs/ProgrammingRuby/html/irb.html#S2

How to create a custom method for my rails model

It seems like all good, just reload your rails console. Rails does not apply changes in your classes immediately.

Defining custom methods within a model/class in Rails 4

Creating method log

Say you have a class User, and within the class, you define the method has_cell_phone. (The contents of that method does not matter.) When you define a method in a class as def has_cell_phone, that method can be called on any User object. While the class User is itself a class object, you would call it on an object whose immediate class is User. In correct terms, you would be writing an instance method for an instance of the User class.

You are getting that error because the method log you defined works only for an _instance of the ActivityLog class. If you do the following, you can call log correctly, given your current code:

activity_log = ActivityLog.create  # with required params
activity_log.log

Secondly, you are calling log with parameters, while your method definition does not require any. (That would look like def log(params).)

Now, here is where you modify your existing code. When you want to call a method on the entire class (meaning the class itself), you prepend the keyword self to the class-method definition. For example, for the User class, it would be def self.create_user_with_cell_phone. You can also add arguments to that method. The arguments you provide in your "method call" line, I would add those to your class method, like so:

def self.log(instance_id, action)
  # ...
end

ActivityLog.log(1, 'create')

You would not need to include the user_id, because, based on your logic, it checks if the current_user object is true, and follows from there.

Creating a class constant

A second look at your question, I found that you are defining a method actions. Remember what I said about instance methods? Since it appears that actions will always remain constant, I recommend that you make it one! To do so, it's recommended you place the following line in your class, before any method definitions.

ACTIONS = ['start','stop','create','destroy']

Then, any time you want to call ACTIONS while inside the ActivityLog class, you do the following: ACTIONS.index(action). If you want to call this constant outside of its class, you would do this: ActivityLog::ACTION. It is similar syntax to a class-method call, instead you use :: to separate the class from the constant. Re-examining your code, it should now look like this:

class ActivityLog < ActiveRecord::Base
  ACTIONS = ['start','stop','create','destroy']

  validates :user_id, :instance_id, :action, presence: true
  validates :user_id, :instance_id, :action, numericality: true

  def self.log(instance_id, action)
    ActivityLog.create(
      user_id: (current_user ? current_user.id : -1),
      instance_id: instance_id,
      action: ACTIONS.index(action)
    )
  end
end

How to make a custom method available in Pry console

In your home directory (~), you can create a file named .pryrc and put a Ruby function in it:

def my_stack(app_name = '')
  caller.select {|line| line.include? app_name }
end

And you can use my_stack or my_stack('myapp') from Pry.

Calling model custom method in controller

Change the class method:

def self.add_manager(params)

To an instance method:

def add_manager(params)

as @rally is an instance of your Rally class

(answered in comments above - removing from unanswered list)

How to make a custom method that can be used anywhere in rails app

Reading the comments it seems like you are just looking for a clear and simple example of a method that is available everywhere in your application:

# in app/models/calculator.rb
module Calculator
  def self.plus_two(x) 
    x + 2 
  end
end

Which can be called like this:

Calculator.plus_two(8)
#=> 10

Rails creating a simple function to run in console for system wide

In case you would like to run custom methods in Rails specifically, you can define you helper methods in a module in lib directory

# lib/custom_console_methods.rb

module CustomConsoleMethods
  def ping
    puts 'pong'
  end
end

Then in the application.rb file, pass a block to console that includes your module into Rails::ConsoleMethods

# config/application.rb

module YourRailsApp
  class Application < Rails::Application
    console do
      require 'custom_console_methods'
      Rails::ConsoleMethods.include(CustomConsoleMethods)
    end
  end
end

If you would like to run it in system wide, just put the methods in ~/.irbrc file. It gets loaded every time you run irb or rails console

def ping
  puts 'pong'
end

How to call custom method in ruby on rails 4?

I'd suggest to move it to your model:

question.rb

def self.ping
  question = Question.first
  question.update(:amplify => question.amplify + 1)
end

and define custom route, routes.rb

post '/ping' => 'questions#ping', as: 'ping'

questions_controller.rb

def ping
   Question.ping
end

then you can reference it from console:

Question.ping

How to store macros in rails console?

well. not actually macros but we have dynamic_method define right.

so u can do this in your rails console:

define_method :bar do
  Apartment::Tenant.switch
end

and then you can call bar method as short for your method.

To add it in initializers i have created one file say bar.rb in initializers folder.

then I have done it , I don't if its ideal:

class Object
    def bar
        Apartment::Tenant.switch
    end
end

restart you console and call bar

Custom extensions for Rails console

You can define helper functions in the file ~/.irbrc. This will affect all of your irb sessions, not just rails console sessions, so you may have to conditionally execute some helpers:

if defined? Rails
  [helper code here...]
end

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