Qt Quick Underscore.js

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h1. Using Underscore.js library in Qt Quick

Underscore is a JavaScript library that provides a whole mess of useful functional programming helpers without extending any built-in objects.

(http://underscorejs.org/)

Unfortunately you cannot just import Underscore like:

import "underscore.js" as Underscore<code>
due "immutable root object":http://doc.qt.io/qt-5/qtqml-javascript-hostenvironment.html#javascript-environment-restrictions

The workaround is to modify ''underscore.js'' so that it returned underscore object via special ''init'' function.

This is a diff output for Underscore.js version 1.4.4:

1,2c1,4 < // Underscore.js 1.4.4 < // = --- > // Underscore.js 1.4.4 > // http://underscorejs.org > // (c) 2009-2013 Jeremy Ashkenas, DocumentCloud Inc. > // Underscore may be freely distributed under the MIT license. 4,10c6,9 < // > http://underscorejs.org < // > (c) 2009-2013 Jeremy Ashkenas, DocumentCloud Inc. < // > Underscore may be freely distributed under the MIT license. < < // Baseline setup < // -------------- < var init = function() { --- > (function() { > > // Baseline setup > // -------------- 58,65c57,64 < // if (typeof exports ! 'undefined') { < // if (typeof module ! &#39;undefined&#39; &amp;&amp; module.exports) { < // exports = module.exports = _; < // } < // exports._ = _; < // } else { < // root._ = _; < // } --- > if (typeof exports ! 'undefined') { > if (typeof module !== 'undefined' && module.exports) { > exports = module.exports = ; > } > exports. = ; > } else { > root. = ; > } 1227,1228c1226 < return; < } — > }).call(this);

Now you can use it in your project:

import "underscore.js" as Underscore // … property var _: Underscore.init();

Drawback of this approach is the following warning in application console: