突变摘要库：如何将html元素附加到添加的元素

Question

I'm using Mutation Summary library to observe when a particular type of elements have been added and then append my html element to each of them:

var observer = new MutationSummary({
      callback: theNextPageLoaded,
      queries: [{
           element: "li.sweet"
      }]
});

function theNextPageLoaded(summaries) {
    var sc = summaries[0],
    sc_length = sc.added.length,
    btn = $('<button>', {
          class: 'my_btn',
          text: 'Please work!'
        });

    sc.added.forEach(function(newEl) {
      newEl.appendChild(btn);
      console.log(typeof(newEl));  //newEl's type is 'object'
    });
}

Code above is not working. I'm not sure I can even use appendChild on an object. Any help would be appreciated!

Answer 1

Your problem is mixing together "bare" DOM elements from Mutation Summary response and jQuery elements. Pure DOM appendChild does not understand your jQuery-wrapped btn .

So, you need to make them both to be the same type:

$(newEl).append(btn); // jQuery
newEl.appendChild(btn.get(0)); // pure DOM

Either works, but the first one is probably more idiomatic.