In Ruby, the use of def self.call(...) new(...).call is a design pattern that leverages class methods to simplify object instantiation and method calling. It essentially turns a class into a callable object, making it more streamlined for certain use cases.
Understanding the Pattern
Here’s a simple example to illustrate:
class Example
def self.call(args)
new(args).call
end
def initialize(args)
@args = args
end
def call
# Perform some action with @args
puts "Called with #{@args}"
end
end
# Usage:
Example.call("Hello, world!")Breakdown
- Class Method (self.call): def self.call(args) defines a class method. Class methods are called on the class itself rather than on instances.
- Instantiating and Calling: Within self.call, new(args).call creates a new instance of the class and immediately calls the call instance method on it.
Benefits
- Simplicity: This pattern simplifies the interface for using the class, reducing the boilerplate code required for creating and using instances.
- Consistency: It provides a consistent way to use classes designed for a specific purpose, often used in service objects, command objects, or similar patterns.
- Clean Code: It promotes clean, readable, and maintainable code, following the single responsibility principle by separating the instantiation and execution logic.
In summary, def self.call(...) new(...).call in Ruby is a powerful pattern for reducing boilerplate and enhancing code readability by turning classes into callable objects.
Published :