d4l3k/WebSync

// https://stackoverflow.com/questions/2891452/jquery-data-selector
(function() {

    var matcher = /\s*(?:((?:(?:\\\.|[^.,])+\.?)+)\s*([!~><=]=|[><])\s*("|')?((?:\\\3|.)*?)\3|(.+?))\s*(?:,|$)/g;

    function resolve(element, data) {

        data = data.match(/(?:\\\.|[^.])+(?=\.|$)/g);

        var cur = jQuery.data(element)[data.shift()];

        while (cur && data[0]) {
            cur = cur[data.shift()];
        }

        return cur || undefined;

    }

    jQuery.expr[':'].data = function(el, i, match) {

        matcher.lastIndex = 0;

        var expr = match[3],
            m,
            check, val,
            allMatch = null,
            foundMatch = false;

        while (m = matcher.exec(expr)) {

            check = m[4];
            val = resolve(el, m[1] || m[5]);

            switch (m[2]) {
                case '==':
                    foundMatch = val == check;
                    break;
                case '!=':
                    foundMatch = val != check;
                    break;
                case '<=':
                    foundMatch = val <= check;
                    break;
                case '>=':
                    foundMatch = val >= check;
                    break;
                case '~=':
                    foundMatch = RegExp(check).test(val);
                    break;
                case '>':
                    foundMatch = val > check;
                    break;
                case '<':
                    foundMatch = val < check;
                    break;
                default:
                    if (m[5]) foundMatch = !! val;
            }

            allMatch = allMatch === null ? foundMatch : allMatch && foundMatch;

        }

        return allMatch;

    };

}());