browserPrefix: function()

in MotionMark/resources/extensions.js [110:142]

• 18 lines of code
• 4 McCabe index (conditional complexity)

    browserPrefix: function()
    {
        if (this._browserPrefix !== undefined)
            return this._browserPrefix;

        // Get the HTML element's CSSStyleDeclaration
        var styles = window.getComputedStyle(document.documentElement, '');

        // Convert the styles list to an array
        var stylesArray = Array.prototype.slice.call(styles);

        // Concatenate all the styles in one big string
        var stylesString = stylesArray.join('');

        // Search the styles string for a known prefix type, settle on Opera if none is found.
        var prefixes = stylesString.match(/-(moz|webkit|ms)-/) || (styles.OLink === '' && ['', 'o']);

        // prefixes has two elements; e.g. for webkit it has ['-webkit-', 'webkit'];
        var prefix = prefixes[1];

        // Have 'O' before 'Moz' in the string so it is matched first.
        var dom = ('WebKit|O|Moz|MS').match(new RegExp(prefix, 'i'))[0];

        // Return all the required prefixes.
        this._browserPrefix = {
            dom: dom,
            lowercase: prefix,
            css: '-' + prefix + '-',
            js: prefix[0].toUpperCase() + prefix.substr(1)
        };

        return this._browserPrefix;
    },