While most of Django core is Python, the admin and gis contrib apps\ncontain JavaScript code.
Please follow these coding standards when writing JavaScript code for inclusion\nin Django.
\nPlease conform to the indentation style dictated in the .editorconfig\nfile. We recommend using a text editor with EditorConfig support to avoid\nindentation and whitespace issues. Most of the JavaScript files use 4 spaces\nfor indentation, but there are some exceptions.
When naming variables, use camelCase instead of underscore_case.\nDifferent JavaScript files sometimes use a different code style. Please try to\nconform to the code style of each file.
Use the JSHint code linter to check your code for bugs and style errors.\nJSHint will be run when you run the JavaScript tests. We also recommended\ninstalling a JSHint plugin in your text editor.
Where possible, write code that will work even if the page structure is later\nchanged with JavaScript. For instance, when binding a click handler, use\n$('body').on('click', selector, func) instead of\n$(selector).click(func). This makes it easier for projects to extend\nDjango's default behavior with JavaScript.
Django's admin system leverages the jQuery framework to increase the\ncapabilities of the admin interface. In conjunction, there is an emphasis on\nadmin JavaScript performance and minimizing overall admin media file size.\nServing compressed or "minified" versions of JavaScript files is considered\nbest practice in this regard.
\nTo that end, patches for JavaScript files should include both the original\ncode for future development (e.g. foo.js), and a compressed version for\nproduction use (e.g. foo.min.js). Any links to the file in the codebase\nshould point to the compressed version.
To simplify the process of providing optimized JavaScript code, Django\nincludes a handy Python script which should be used to create a "minified"\nversion. To run it:
\n$ pip install closure\n$ python django/contrib/admin/bin/compress.py\nBehind the scenes, compress.py is a front-end for Google's\nClosure Compiler which is written in Java. The Closure Compiler library is\nnot bundled with Django, but you can install it using pip as done above. The\nClosure Compiler library requires Java 7 or higher.
Please don't forget to run compress.py and include the diff of the\nminified scripts when submitting patches for Django's JavaScript.
Django's JavaScript tests can be run in a browser or from the command line.\nThe tests are located in a top level js_tests directory.
Django's JavaScript tests use QUnit. Here is an example test module:
\nQUnit.module('magicTricks', {\n beforeEach: function() {\n var $ = django.jQuery;\n $('#qunit-fixture').append('<button class="button"></button>');\n }\n});\n\nQUnit.test('removeOnClick removes button on click', function(assert) {\n var $ = django.jQuery;\n removeOnClick('.button');\n assert.equal($('.button').length, 1);\n $('.button').click();\n assert.equal($('.button').length, 0);\n});\n\nQUnit.test('copyOnClick adds button on click', function(assert) {\n var $ = django.jQuery;\n copyOnClick('.button');\n assert.equal($('.button').length, 1);\n $('.button').click();\n assert.equal($('.button').length, 2);\n});\nPlease consult the QUnit documentation for information on the types of\nassertions supported by QUnit.
\nThe JavaScript tests may be run from a web browser or from the command line.
\nTo run the tests from a web browser, open up js_tests/tests.html in your\nbrowser.
To measure code coverage when running the tests, you need to view that file\nover HTTP. To view code coverage:
\nExecute python -m http.server from the root directory (not from inside\njs_tests).
Open http://localhost:8000/js_tests/tests.html in your web browser.
To run the tests from the command line, you need to have Node.js installed.
\nAfter installing Node.js, install the JavaScript test dependencies by running\nthe following from the root of your Django checkout:
\n$ npm install\nThen run the tests with:
\n$ npm test\n