Using the Revealing Module Pattern in Javascript GitHub

It also makes it easier to tell at the end of the module which of our functions and variables may be accessed publicly, which eases readability. Once the Calculator function is invoked and assigned to the myCalc variable, the public functions exposed by Calculator can be called through myCalc. For example, the previous code uses myCalc to call the Calculator object’s init() function. This is a very clean way of specifying the public members and functions that you want to define to the outside world. The biggest advantage of revealing module pattern as compared to the module pattern is the code readability aspect. Basically, we’ve created a module that’s accessible globally while protecting the private members and functions that we do not want to expose.

While solving many problems using technology, writing clean code is a must-do for every developer because it can save tons of resources, time and money in the future. As shown in the above pictorial representation , several methods combined together makes a big function functionality working . These shown methods would be embedded inside the bigger method which is the main method visible to the user, which will function at first itself. As a result of this, modules created with the Revealing Module pattern may be more fragile than those created with the original Module pattern, so care should be taken during usage.

Allows you to keep most of your variables and functions out of the global scope, but make some of them publicly available. We are storing returned public methods in namesCollection variable. Now you can call namesCollection.addObject() method, which is a public method. But can not call printMessage method because this is not exposed in return.

You can use double underscore prefix for event binding function, to separate it from private functions. The function ‘addProperty’ will not be invoked while running the IIFE and hence the console.log statement inside the function will not run. Now that we have the fundamentals of IIFE in place, let us look take a step-by-step approach to create a module pattern.

Sign up or log in

As you can see your code has become more readable now, since your event bindings are at top and their respective functions are at bottom. In this blog post, we will discuss the basics of the Revealing Module Pattern and provide some examples of how it can be used in a complex application. If you’re interested in additional information about structuring JavaScript code check out my Pluralsight course. This post covers patterns and techniques found in Dan Wahlin’sStructuring JavaScript Codecourse on Pluralsight.com. Closures are often considered a complex subject in Javascript and may be difficult to understand for beginner developers. Can be repurposed to return any of the previously mentioned Patterns yielding the advantages of other patterns while mitigating the disadvantages.

If you wish to change this at any time you may do so by clicking here. I agree to receive email communications from Progress Software or its Partners, containing information about Progress Software’s products. I acknowledge my data will be used in accordance with Progress’ Privacy Policy and understand I may withdraw my consent at any time. Leonardo is a full-stack developer, working with everything React-related, and loves to write about React and GraphQL to help developers. Noticed that we’re using an IIFE and returning an object instead of any other value. The add(), subtract(), multiply(), and divide() methods accept two or more numbers as arguments, and add, subtract, multiply, or divide them together, respectively.

For every programming language, there are design patterns that were created throughout the years, based on the experience of many developers. Design patterns are proven solutions, tested many times, that improve communication and make code reusable. To create a revealing module pattern, you assign an immediately invoked function expression to a variable. He also disliked the Module pattern’s requirement of having to switch to object literal notation for the things he wished to make public.

It’s yours, free.

For this solution, we will create a Script Include which can be accessed by all Scopes but is ultimately Protected to mask the source code when purchased from the store. If you wanted to make name and sayHello private, you just need to comment out the appropriate lines in the return object. Telerik and Kendo UI are part of Progress product portfolio. Progress is the leading provider of application development and digital experience technologies. We see that you have already chosen to receive marketing materials from us.

• For every programming language, there are design patterns that were created throughout the years, based on the experience of many developers.
• The major difference to be aware of is simply how the revealing module pattern exposes it’s api.
• In addition, you probably would never notice performance problems until you start hitting thousands or hundreds of thousands of instances of a module on a page.
• This pattern lets you scope all of your functions to a specific namespace, which helps prevent naming collisions with other functions.
• The revealing module pattern is really almost the same as the module pattern.

Note that unlike RMP, in order to make name and sayHello private, the references pointing to name and sayHello in the various function body definitions also have to be changed. Modules are an important piece of every modern application. They help us to organize and structure our codebase in a better way. When we’re writing code, breaking our code into small and manageable modules makes a difference in how our application is going to scale. As developers, we’re always striving to write clean and readable code.

codepen.io

This pattern is the same concept as the module pattern in that it focuses on public & private methods. 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. Functions that should be exposed publicly are defined in the return section of the calculator object. All of the other functions and variables defined in the calculator object are private. JavaScript doesn’t support accessibility modifiers as C# or Java do but this pattern provides a nice way to emulate that type of functionality.

Although it doesn’t offer the benefit of sharing functions implementations across objects through JavaScript’s prototype feature, it’s definitely a viable option. There’s no way to define whether a function, variable or any other structure should be global or private in JavaScript. We don’t have access modifiers (keywords in object-oriented languages that set the accessibility of classes, methods and other members) in JavaScript, and this is why the scope is very important.

Of course the example names here are far from what I would use in a real script, but it shows the power of this pattern. During a Q&A session in a training in Hongkong yesterday I showed this to Douglas Crockford and asked him what he thinks of it. He didn’t mind the idea, but considered even the pub object redundant. Demos of all the patterns covered in this series can be downloaded below.

Simply leave off the immediately invoking () parenthesis after the module declaration, change the module name to lowercase , then new up at will. The module Shopifys Technical Interview Process: What to Expect and How to Prepare Culture pattern keeps the privacy of the state and organizes using closures. It protects the pieces from the global scope, avoiding possible errors and conflicts.

General Revealing Module Pattern Structure

The module pattern is yet another way of declaring and making reusable code. Javascript does not have the typical ‘private’ and ‘public’ specifiers of more traditional object oriented languages like C# or Java. However, you can achieve the same effect through the clever application of Javascript’s function-level scoping. The Revealing Module pattern is a design pattern for Javascript applications that elegantly solves this problem.

The Install SQL Server on a Mac can also be useful in more complex applications. For example, let’s say we have an application that needs to access a remote API to retrieve data. We can use the Revealing Module Pattern to create a module that handles the API calls and exposes a small number of public methods for retrieving and manipulating the data. It’s harder to patch public methods and variables that are referred to by something private. One of my favorite overall JavaScript patterns is the Revealing Module Pattern since it’s cleaner with less usage of the “this” keyword. I also like the fact that it doesn’t separate code into constructor and prototype sections.

JavaScript Revealing Module Pattern

The central principle of the Revealing Module pattern is that all functionality and variables should be hidden unless deliberately exposed. The Revealing Module Pattern is a variation of the traditional module pattern that allows for more flexibility and control when creating modules. JavaScript is a powerful and versatile language that has become a mainstay in web development. One of the key features of the language is its ability to create modules, which are self-contained chunks of code that can be reused across an application. Encapsulation, or information hiding in other words, is one of the core characteristics of every module system.

Based on either your previous activity on our websites or our ongoing relationship, we will keep you updated on our products, solutions, services, company news and events. If you decide that you want to be removed from our mailing lists at any time, you can change your contact preferences by clicking The Ultimate List of Interview Questions to Ask Remote Workers here. Unless otherwise noted, all code is free to use under the MIT License. I send out a short email each weekday on how to build a simpler, more resilient web. It’s only intended to be used inside other functions in our library. We can abstract that bit of code into a getTotal() helper function.

The team is concerned about granting direct table access to users since at best some data will make no sense to the user and at worst, random table edits could corrupt the application data. To remedy this, the team has locked all tables within the scope to only allow access via a Script Include API. Using our old example, you can see that public members are directly added to the stub object. Change members from public to private or vice versa by modifying a single line, without changing the function body. Any functions we don’t explicitly return can only be accessed inside the IIFE itself. For example, all four of our calculator functions include a bit of code that checks how many numbers were passed in.