Module: Komando::Command::Dsl

Defined in:
lib/komando/command/dsl.rb

Overview

The Komando DSL. Extend your command classes with this module to start using Komando in your application.

It is recommended you do not implement #initialize in your commands. If you do, you must call super or your parameters will not be available as instance variables.

Examples:


require "komando/command/dsl"

class CreateUserCommand
  extend Komando::Command::Dsl

  # If you must override #initialize, make sure you call super,
  # or your instance variables won't be assigned.
  def initialize(*args)
    super # MUST call, or all hell will break loose
  end

  mandatory_step "generate records" do
    # TODO
  end

  mandatory_step "generate audit log" do
    # TODO
  end

end

Instance Method Summary collapse

Instance Method Details

#best_effort_step(name = nil, &block) ⇒ Object

Declares a new best effort step - one that will be executed, but will not stop processing. If the block raises an exception, Komando::Command#run! will log and swallow the exception. Best effort stop blocks have access to the same environment as #mandatory_step blocks - they execute within the same instance. You can pass values from one block to the next by using instance variables.

Examples:


class CreateUserCommand
  extend Komando::Command::Dsl

  mandatory_step do
    @user = User.create!(@attributes)
  end

  best_effort_step("generate audit log record") do
    AuditLog.append(@user, @created_by)
  end
end

# Run the command with parameters gathered from the environment
CreateUserCommand.new(:attributes => params[:user], :created_by => current_user).run!


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# File 'lib/komando/command/dsl.rb', line 82

def best_effort_step(name=nil, &block)
  @best_effort_steps ||= Array.new
  @best_effort_steps << [name, block]
end

#best_effort_steps ⇒ Array

Helper method to access the declared blocks.

Returns:

  • (Array) —

    The list of best effort blocks that were collected. This array may be empty.



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# File 'lib/komando/command/dsl.rb', line 90

def best_effort_steps
  @best_effort_steps ||= Array.new
end

#mandatory_step(name = nil, &block) ⇒ Object

Declares a set of actions that must run to completion for this command to be deemed successful. The declared actions may be anything: method calls or direct actions. Parameters are passed from the environment as instance variables passed to the instance.

Examples:


class CreateUserCommand
  extend Komando::Command::Dsl

  mandatory_step do
    # Assuming an ActiveRecord-like User class exists
    User.create!(@attributes)
  end
end

# Run the command with parameters gathered from the environment
CreateUserCommand.new(:attributes => params[:user]).run!


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# File 'lib/komando/command/dsl.rb', line 56

def mandatory_step(name=nil, &block)
  mandatory_steps << block
end

#mandatory_steps ⇒ Object

Returns the list of mandatory steps



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# File 'lib/komando/command/dsl.rb', line 35

def mandatory_steps
  @mandatory_steps ||= []
end