javascript-新建 <li> 带有按钮的textarea onclick的元素

Question

HTML:

<li><textarea></textarea></li><br><a id="newPoints"></a>
<input type="button" value="+ Add new point" onclick="newPoint();">

CSS (if you need it):

textarea {
    font-family: Georgia, 'Times New Roman', Times, serif;
    vertical-align: text-top;
    width: 300px;
    height: 60px;
    resize: vertical;
    padding: 10px;
}

And Javascript:

function newPoint() {
    var a = document.getElementById("newPoints");
    a.innerHTML += '<li><textarea placeholder="To delete this point, select this textbox and press the &quot;Delete&quot; button on your keyboard." onkeydown="if(event.keyCode == 46) { this.parentNode.nextSibling.parentNode.removeChild(this.parentNode.nextSibling); this.parentNode.parentNode.removeChild(this.parentNode); }"></textarea></li><br>';
}

To better visualise, here's a fiddle .

So basically, with the code above, I'm trying to make it such that when the user clicks on the button, a new <li> (that comes with a <br> after it) that contains a <textarea> will get created. This new <li> , <textarea> and the following <br> will be deleted when the user presses the Delete button on their keyboard while selecting the textarea.

The problem is that, when the user creates a new <li> and types some text into its textarea, then create another <li> , the text from the textarea of the previous <li> will disappear.

How can I fix this?

Answer 1

Use CreateElement and appendChild to add the elements. I think what is happening is when you append to the innerHTML, it is overwriting everything in newPoints .

function newPoint() {
    var a = document.getElementById("newPoints");
    var l = document.createElement("li");
    l.innerHTML = '<textarea placeholder="To delete this point, select this textbox and press the &quot;Delete&quot; button on your keyboard." onkeydown="if(event.keyCode == 46) { this.parentNode.nextSibling.parentNode.removeChild(this.parentNode.nextSibling); this.parentNode.parentNode.removeChild(this.parentNode); }"></textarea>';
    var b = document.createElement("br");
    a.appendChild(l);
    a.appendChild(b);
}

http://jsfiddle.net/MzENe/1/

Answer 2

This might help:

function newPoint() {
    var a = document.getElementById("newPoints");
    var newcontent = document.createElement('li');
    newcontent.innerHTML = "<textarea placeholder='To delete this point, select this textbox and press the &quot;Delete&quot; button on your keyboard.' onkeydown=\"if(event.keyCode == 46) {  this.parentNode.parentNode.removeChild(this.parentNode);}\"></textarea>";
    a.appendChild(newcontent);
}