– Principles of Writing Consistent, Idiomatic JavaScript When a statement is too long to fit on one line, line breaks must occur after an operator. The WordPress JavaScript Coding Standards are adapted from the jQuery JavaScript Style Guide. Please follow these guidelines when you submit a patch for review. To avoid these problems, always use lower case file names (if possible). These deviations are for consistency between the PHP and JavaScript files in the WordPress codebase. leading spaces. Code in HTML adds significantly to pageweight with no opportunity for mitigation by caching, minification, and compression. In almost all cases, a constant should be defined in the top-most scope of a file. This guide serves as the coding standard for all Appcelerator JavaScript code including the Mobile Web platform, Titanium Mobile project templates, KitchenSink, and all other sample code. Put the opening bracket at the end of the first line. WordPress requires PHP 5.6.20 files in WordPress core Core Core is the set of software required to run WordPress. The closing brace should be on the line directly following the last statement of the block. JavaScript code has a column limit of 80 characters. All code in any code-base should look like a single person typed it, no matter how many people contributed. Now it is practically unheard of for a website not to utilize JavaScript to some extent. "Fiat"]; var person = {firstName:"John", lastName:"Doe", age:50, eyeColor:"blue"}; document.getElementById("demo").innerHTML =, W3Schools is optimized for learning and training. If a JavaScript statement does not fit on one line, the best place to break If you are accessing a global which is defined elsewhere, omit :true to designate the global as read-only. Backbone and Underscore may be accessed directly at any time. No whitespace at the end of line or on blank lines. Object declarations can be made on a single line if they are short (remember the line length guidelines). Comments come before the code to which they refer, and should always be preceded by a blank line. Pull requests 3. Do not start names with a $ sign. Rules for the use of white space, indentation, and comments. When a conditional is too long to fit on one line, each operand of a logical operator in the boolean expression must appear on its own line, indented one extra level from the opening and closing parentheses. This module saves you (and others!) JavaScript coding standards for improving the quality of your code. As a web developer who has concentrated on back-end coding in C# and front-end look and feel via HTML and CSS, my skills in JavaScript evolved over time instead of by conscious effort. JSHint is an automated code quality tool, designed to catch errors in your JavaScript code. @lends This tag will allow JSDoc to recognize the extend function from Backbone as a class definition. These functions, including _.each, _.map, and _.reduce, allow for efficient, readable transformations of large data sets. Backbone, jQuery, Underscore, and the global wp object are all registered as allowed globals in the root .jshintrc file. This text is a brief overview of JerryScript Coding Standards. Each rule starts with a short description followed by several examples. Even if the entire file is contained in a closure (i.e., an immediately invoked function), the contents of that function should be indented by one tab: if, else, for, while, and try blocks should always use braces, and always go on multiple lines. If you want to report an error, or if you want to make a suggestion, do not hesitate to send us an e-mail: var values = ["Volvo", "Saab", Use spaces liberally throughout your code. When an object declaration is too long to fit on one line, there must be one property per line. JerryScript Coding Standards. Always use the same naming convention for all your code. Files which add to, or modify, the wp object must safely access the global to avoid overwriting previously set properties: Variable and function names should be full words, using camel case with a lowercase first letter. Each function should begin with a single comma-delimited var statement that declares any local variables necessary. The configuration options used for JSHint are stored within a .jshintrc title=”WordPress JSHint file in svn trunk” in the WordPress SVN repository. Object properties should be accessed via dot notation, unless the key is a variable or a string that would not be a valid identifier: When iterating over a large collection using a for loop, it is recommended to store the loop’s max value as a variable rather than re-computing the maximum every time: Learn and understand Underscore’s collection and array methods. and ??). They typically cover: Coding conventions can be documented rules for teams to follow, or just be your individual coding practice. 4. if… The package.json configuration file that comes with the WordPress development code allows you to install and configure these tools. – Principles of Writing Consistent, Idiomatic JavaScript. Creating arrays in JavaScript should be done using the shorthand [] constructor rather than the new Array() notation. Put the closing bracket on a new line, without leading spaces. Lines should usually be no longer than 80 characters, and should not exceed 100 (counting tabs as 4 spaces). jQuery’s 100-character hard line limit is encouraged, but not strictly enforced. This document outlines technical and style guidelines which are followed in Phabricator and Javelin. it, is after an operator or a comma. JPL have been developing software for most of unmanned missions in the field of deep space and other planets exploration. If an abbreviation or an acronym occurs at the start of a variable name, it must be written to respect the camelcase naming rules covering the first letter of a variable or class definition. A class definition must use the UpperCamelCase convention, regardless of whether it is intended to be used with new construction. JSDoc comments should use the /** multi-line comment opening. The opening brace should be on the same line as the function definition, the conditional, or the loop. Install ESLint with the command npm install -g eslint (npm is a JavaScript package installer). Applying NASA coding standards to JavaScript Jet Propulsion Laboratory – scientific institution making a lot of research and development for NASA . For class definitions, its initial letter should be capitalized. Tabs should be used for indentation. databases. NOTICE OF CONFIDENTIALITY . Code style is about consistency and discipline, and there's no real right or wrong. There should be a new line at the end of each file. It is provided primarily as an online tool, but there are also command-line adaptations. Coding style must follow the idiomatic.js style but with the following exceptions. This document provides the JavaScript coding standards for development. The correct install file for your operating system will be downloaded. camelCase is used by JavaScript itself, by jQuery, and other JavaScript necessary): A consequence of using "untidy" HTML styles, might result in JavaScript errors. And this would only check the “password-strength-meter.js” file within the unit tests directory: npm run grunt jshint:tests --file=password-strength-meter.js. Object literal notation should be used unless the object requires a specific prototype, in which case the object should be created by calling a constructor function with new. Acronyms must be written with each of its composing letters capitalized. “When in doubt, space it out.”. Some whitespace rules differ, for consistency with the WordPress PHP coding standards. Underscores are often used in PHP documentation. While the coding standards are important, refactoring older .js files simply to conform to the standards is not an urgent issue. For example, this will only check the file named “admin-bar.js” within WordPress’s core JavaScript files: npm run grunt jshint:core --file=admin-bar.js. JavaScript References. Coding conventions are not used by computers. Always include extra spaces around elements and arguments: Use them. Javascript Coding Standards Overview Javascript Platform Roadmap Standards References: Other Resources: ECMA Script 5 Development Platform Javascript IDE Web Container Logging MVC Package Layout Components Controllers Delegates Events Callbacks Models Data Models Request Models Services Common Data Service Implementing a Data Service Views To exclude a specific file region from being processed by JSHint, enclose it in JSHint directive comments: Principles of Writing Consistent, Idiomatic JavaScript. 1. JavaScript has become a critical component in developing WordPress-based applications (themes and plugins) as well as WordPress core. Stick to a strict coding style. While using W3Schools, you agree to have read and accepted our. Always end a simple statement with a semicolon. Object literal notation, {}, is both the most performant, and also the easiest to read. Raw JavaScript Can Always Be Quicker Than Using a Library . At the bottom of this page, you will find a wider discussion about naming To only check core code, type npm run grunt jshint:core; to only check unit test .js files, type npm run grunt jshint:tests. The reference contains examples for all properties, methods and events, and is continuously updated according to the latest web standards. The argument behind defining the style guide is that “ long term value of the software is directly proportional to the quality of codebase ”. libraries. between properties, like this: For readability, avoid lines longer than 80 JavaScript Coding Standards Version: 1.0 4/6/2015. To install Node.js, click the Install link on the Node.js website. Property names only need to be quoted if they are reserved words or contain special characters: Objects and arrays can be declared on a single line if they are short (remember the line length guidelines). All variables, functions, methods, class names, and comments SHOULD be written in English. All code in any code-base should look like a single person typed it, no matter how many people contributed. Security Insights Dismiss Join GitHub today. This example would make passwordStrength an allowed global variable within that file: The “true” after passwordStrength means that this global is being defined within this file. When an object or array is too long to fit on one line, each member must be placed on its own line and each line ended by a comma. Refer to the JavaScript Documentation Standards for more information. eslint settings to impose Drupal JavaScript coding standards. Never rely on Automatic Semicolon Insertion (ASI). “Code refactoring should not be done just because we can.” – Lead Developer Andrew Nacin. Lines should be broken into logical groups if it improves readability, such as splitting each expression of a ternary operator onto its own line, even if both will fit on a single line. For code in development, readability should be preferred. ES module import and … If you use a mix of upper and lower case, you have to be extremely Rules for the use of white space, indentation, and comments. In some situations, parts of a file should be excluded from JSHint. Always put spaces around operators ( = + - * / ), and after commas: Always use 2 spaces for indentation of code blocks: Do not use tabs (tabulators) for indentation. The minification process creates a file that is optimized for browsers to read and process. Having said that, always keep in mind that a library can never be as fast as raw JavaScript (assuming you code correctly). Hyphens are not allowed in JavaScript names. “Whitespace-only” patches for older files are strongly discouraged. Any violation to these standards is allowed if it enhances readability. All JavaScript in the Umbraco core should adhere to these guidelines. Indentation with tabs. If the method changes the context, an extra level of indentation must be used. The legacy JavaScript code in the core doesn't adhere to these guidelines but should be refactored so that it does. Create a config file named .eslintrc in the root of your JavaScript project (in the folder that contains all your files). These two JavaScript statements will produce different results: If possible, use the same naming convention (as JavaScript) in HTML. Many of these guidelines are … Always end an object definition with a semicolon. little impact on the execution of programs. whichdigital / javascript-coding-standards forked from airbnb/javascript. WordPress is working to gradually improve this, so the code will be clean and easy to read at a glance. “When in doubt, space it out.” These rules encourage liberal spacing for improved developer readability. Multiple globals can be comma-separated. It is not recommended to return a value from within a switch statement: use the case blocks to set values, then return those values at the end. This is contrary to the OKFN Coding Standards but matches what’s in use in the current code base. This is an area where this standard differs from the WordPress PHP coding standards. GitHub is home to over 40 million developers working together to host and review code, manage projects, and build software together. rules. There are many ways to create objects in JavaScript. Actions Projects 0. To specify a single file for JSHint to check, add --file=filename.js to the end of the command. Both JSHint and Grunt are programs written in Node.js. You can initialize an array during construction: In JavaScript, associative arrays are defined as objects. We believe examples are better than long explanations. Examples might be simplified to improve reading and learning. They typically cover: Naming and declaration rules for variables and functions. PascalCase is often preferred by C programmers. For code written using ES2015 or newer, const and let should always be used in place of var. If you move from a case insensitive, to a case sensitive server, even small Different editors interpret tabs differently. All @wordpress/element Components, including stateless function components, should be named using Class Definition naming rules, both for consistency and to reflect the fact that a component may need to be transitioned from a function to a class without breaking compatibility. Always use the same coding conventions for all your JavaScript Rohan Shakya. Watch 64 Star 1 Fork 17.9k Code. Developers writing JavaScript and jQuery code for Magento must adhere to these guidelines and follow the standards listed in this document. JavaScript files should have a .js extension. Contributors should also follow these guidelines. Tutorials, references, and examples are constantly reviewed to avoid errors, but we cannot warrant full correctness of all content. JSHint is run using a tool called Grunt. errors can break your web site. It will put you in conflict with many JavaScript library names. These rules encourage liberal spacing for improved developer readability. 3. No whitespace at the end of line or on blank lines. Expand full source code Collapse full source code. This is intended to reflect that each letter of the acronym is a proper word in its expanded form. consistent. Standards are needed for formatting and styling JavaScript code to maintain the same code consistency as the WordPress standards provide for core PHP, HTML, and CSS code. Programming practices and principles; Coding conventions secure quality: Improves code readability; Make code maintenance easier Capitalize the first letter of the comment, and include a period at the end when writing full sentences. checked out a copy of the WordPress SVN repository. All function bodies are indented by one tab, even if the entire file is wrapped in a closure. projects. Names should be descriptive, but not excessively so. One way to catch whitespace buildup is enabling visible whitespace characters within your text editor. The web is for everybody, not an elite group of users with a state-of-the-art configuration. Our standard differs from the jQuery guidelines in the following ways: Many of the examples below have been adapted directly from the jQuery style guide; these differences have all been integrated into the examples on this page. Coding conventions are style guidelines for programming. ESLint settings. This should be placed right before the Object that contains the class definition. CSS uses hyphens in property-names (font-size). Limiting JSHint to a single file can be useful if you are only working on one or two specific files and don’t want to wait for JSHint to process every single file each time it runs. For example: Should you use hyp-hens, camelCase, or Standards are needed for formatting and styling JavaScript code to maintain the same code consistency as the WordPress standards provide for core PHP, HTML, and CSS code. Place the opening bracket on the same line as the object name. Underscore also permits jQuery-style chaining with regular JavaScript objects: The only time jQuery should be used for iteration is when iterating over a collection of jQuery objects: Never use jQuery to iterate over raw data or vanilla JavaScript objects. JavaScript API documentation and comment standards. Overview. Any of the below standards and examples should be considered best practice for WordPress code, unless explicitly noted as anti-patterns. All JavaScript in the backoffice needs to be in a namespace and defined in a class. This page covers DOM and Drupal specific code styles. You should now be able to type npm run grunt jshint to have Grunt check all the WordPress JavaScript files for syntax and logic errors. Exceptions: goog.module, goog.require and goog.requireType statements (see ?? Use simple syntax for loading external scripts (the type attribute is not This is wasted time and effort — we should build code based on agreed standards as outlined in this course of articles, not for one browser. JavaScript coding standards. Constructors intended for use with new should have a capital first letter (UpperCamelCase). Crockfords’s Coding Standards for JavaScript This one is the creation of Douglus Crockford, a JavaScript enthusiast. Use spaces liberally throughout your code. JavaScript Coding Standards itself is indented four spaces. WordPress uses single quotation marks for string declarations. Code refactoring should not be done just because we can. The coding standards below are my own opinion on what can help with the above points, using what I have experienced whilst developing and reviewing other developers JavaScript. Backbone’s extend calls should be formatted as follows:. Hyphens can be mistaken as subtraction attempts. This is a “soft” rule, but long lines generally indicate unreadable or disorganized code. Coding Style. Top ↑ Backbone classes # Backbone classes. JavaScript coding standards and guidelines. Indentation and line breaks add readability to complex statements. ... is a static code analysis tool used in software development for checking if JavaScript source code complies with coding rules. Our code must be as clean and easy to read as possible. 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