The Revealing Module Pattern

This pattern is the same concept as the module pattern in that it focuses on public & private methods. The only difference is that the revealing module pattern was engineered as a way to ensure that all methods and variables are kept private until they are explicitly exposed; usually through an object literal returned by the closure from which it’s defined. Personally, I like this approach for vanilla JavaScript as it puts a clear emphasis on both the intent of the developer and the module itself.

“I’ve used this pattern on projects ranging from 100 to 100,000 lines of code.” – Bob Holt

This article is part of a series called JavaScript Design Patterns.

Advantages

Disadvantages

Example

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var MyModule = ( function( window, undefined ) {
function myMethod() {
alert( 'my method' );
}
function myOtherMethod() {
alert( 'my other method' );
}
// explicitly return public methods when this object is instantiated
return {
someMethod : myMethod,
someOtherMethod : myOtherMethod
};
} )( window );
 
// example usage
MyModule.myMethod(); // undefined
MyModule.myOtherMethod(); // undefined
MyModule.someMethod(); // alerts "my method"
MyModule.someOtherMethod(); // alerts "my other method"

This pattern can also be implemented using a privately shared cache (see Example 2 of the module pattern for an example.)

Additional Resources

http://www.raymondcamden.com/index.cfm/2013/5/13/JavaScript-Design-Patterns–The-Revealing-Module-Pattern
http://www.bobholt.me/2012/08/using-the-revealing-module-pattern/
http://addyosmani.com/resources/essentialjsdesignpatterns/book/#revealingmodulepatternjavascript

Other Common JS Patterns

The Module Pattern
The Revealing Module Pattern
The Singleton Pattern
The Observer Pattern
The Mediator Pattern
The Prototype Pattern
The Facade Pattern
The Factory Pattern

2 responses!

JavaScript应用设计模式 | 游侠博客 said: (5 months ago) Reply

[…] 揭示模块模式 […]

Nicolas said: (4 months ago) Reply

Can you give an example with code regarding the disadvantages of the revealing module pattern. I don’t think I get it. Won’t you have the same problems with a common module ? I’m reading Addy Osmany’s book and it does’t clarifies it.

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