ROS JavaScript Style Guide

This page defines a style guide to be followed in writing JavaScript code for ROS. This guide applies to all ROS code, both core and non-core.

For Python, see the Python Style Guide and for C++, see the C++ Style Guide

Coding Style

A quick summary is:

• 2 space indention

  • function foo() {
      var indentation = 2;
    }

• Camel case variables and function names

  • var myNewVariable = 'robots';

• Capital camel case for classes

  • MyNewClass = function() { ... };

• Single-word caps for namespaces (typically ending in JS)

  • ROBOTJS.MyNewClass = function() { ... };

• Underscored caps for constants

  • ROBOTJS.MY_NEW_CONST = 3.14;

• Options object for all class constructors

• Public functions should use prototype

• Semicolons are required

• JSDoc for documentation

• Triple equals (===) for comparisons

• Single quotes for strings
• Same-line brackets

An example can be worth a thousand words:

/**
 * Performs an example task.
 *
 * @param options - possible keys include:
 *   * myMessage (optional) - an example message
 */
ROBOTJS.MyAwesomeClas = function (options) {
  options = options || {};
  var myMessage = options.myMessage || 'My message';

  if (myMessage === 'Do this') {
    alert('Not a pubic function');
  }
  else {
    this.myPublicFunction(myVar);
  }
};

/**
 * Alert a string in this public function.
 *
 * @param str - a string to alert
 */
ROBOTJS.MyAwesomeClas.prototype.myPublicFunction = function(str) {
  alert(str);
};

Linting

Linting of JavaScript files should be done using JSHint. The standard configuration file can be found on the Robot Web Tools GitHub.