rarjpeg detector

application.js

(function (rarDetected) {
    function detectRar(blob, callback) {
        var reader = new FileReader;
        reader.readAsBinaryString(blob);
        reader.onload = function () {
            callback(reader.result.indexOf('Rar!') != -1)
        }
    }

    function getBlob(url, callback) {
        var xhr = new XMLHttpRequest();
        xhr.responseType = 'arraybuffer';
        xhr.open('GET', url, true);
        xhr.send();
        xhr.onload = function () {
            callback(new Blob([xhr.response]))
        }
    }

    function imageProcessor(image) {
        if (!image.complete) return image.addEventListener('load', imageProcessor.bind(image));
        image.crossOrigin = 'Anonymous';
        getBlob(image.src, function (blob) {
            detectRar(blob, function (isRar) {
                if (isRar) {
                    rarDetected(image.src, blob);
                }
            })
        })
    }

    function imageDetector(nodeList) {
        if (nodeList && nodeList.length) for (var i = 0; i < nodeList.length; i++) {
            var node = nodeList[i];
            if (node.children) setTimeout(imageDetector.bind(node.children), 100);
            if (node.tagName == (new Image).tagName) imageProcessor(node);
        }
    }

    function mutationRecordProcessor(mutationRecordList) {
        mutationRecordList.forEach(function (mutationRecord) {
            imageDetector(mutationRecord.addedNodes)
        })
    }

    (new MutationObserver(mutationRecordProcessor)).observe(document.body, {
        childList: true,
        subtree: true
    });
    if (document.body) imageDetector(document.body.children);
})(function rarDetected(url, data) {
    console.log(url)
});