invisible-watermark/lib/mutationObserver.js

watermark auto injector

var MutationObserver = window.MutationObserver ||
    window.WebKitMutationObserver ||
    window.MozMutationObserver;
var supportMutationObserver = !!MutationObserver;
var watermarkDefaultConfig = {
    attributes: true,
    attributeOldValue: true,
    childList: true,
};
function watermarkCallback(mutationList, observer) {
    mutationList.forEach(function (mutationRecord) {
        var type = mutationRecord.type, attributeName = mutationRecord.attributeName, target = mutationRecord.target, oldValue = mutationRecord.oldValue, addedNodes = mutationRecord.addedNodes, removedNodes = mutationRecord.removedNodes;
        if (type === 'attributes') {
            observer.disconnect();
            if (attributeName === 'style') {
                target.style = oldValue;
            }
            else if (attributeName === 'id') {
                target.id = oldValue;
            }
            observer.observe(target, watermarkDefaultConfig);
        }
        if (type === 'childList' && !addedNodes[0] && removedNodes[0]) {
            //判断删除的节点s中是否有水印的dom，有的话重新插入
            Array.prototype.forEach.call(removedNodes, function (item) {
                if (item.id.match(/^wm_/)) {
                    observer.disconnect();
                    document.body.append(item);
                    observer.observe(target, watermarkDefaultConfig);
                }
            });
        }
    });
}
function initObserver($el, config) {
    if (!$el)
        return;
    if (supportMutationObserver) {
        var om = new MutationObserver(watermarkCallback);
        om.observe($el, watermarkDefaultConfig);
    }
}
export default initObserver;