Pooja in Web Development

I'm refactoring some old JavaScript code and there's a lot of DOM manipulation going on.

var d = document;
var odv = d.createElement("div");
odv.style.display = "none";
this.OuterDiv = odv;

var t = d.createElement("table");
t.cellSpacing = 0;
t.className = "text";
odv.appendChild(t);

I would like to know if there is a better way to do this using jQuery. I've been experimenting with:

var odv = $.create("div");
$.append(odv);
// And many more

But I'm not sure if this is any better.

5 Answers

0 votes
Nadira

Here's your example in the "one" line.

this.$OuterDiv = $('<div></div>')
 .hide()
 .append($('<table></table>')
 .attr({ cellSpacing : 0 })
 .addClass("text")
 )
;

Update: I thought I'd update this post since it still gets quite a bit of traffic. In the comments below there's some discussion about $("<div>") vs $("<div></div>") vs $(document.createElement('div')) as a way of creating new elements, and which is "best".

I put together a small benchmark, and here are roughly the results of repeating the above options 100,000 times:

jQuery 1.4, 1.5, 1.6

 Chrome 11 Firefox 4 IE9
<div> 440ms 640ms 460ms
<div></div> 420ms 650ms 480ms
createElement 100ms 180ms 300ms

jQuery 1.3

 Chrome 11
<div> 770ms
<div></div> 3800ms
createElement 100ms

jQuery 1.2

 Chrome 11
<div> 3500ms
<div></div> 3500ms
createElement 100ms

I think it's no big surprise, but document.createElement is the fastest method. Of course, before you go off and start refactoring your entire codebase, remember that the differences we're talking about here (in all but the archaic versions of jQuery) equate to about an extra 3 milliseconds per thousand elements.


Update 2

Updated for jQuery 1.7.2 and put the benchmark on JSBen.ch which is probably a bit more scientific than my primitive benchmarks, plus it can be crowdsourced now!

0 votes
Nadira

Simply supplying the HTML of elements you want to add to a jQuery constructor $() will return a jQuery object from newly built HTML, suitable for being appended into the DOM using jQuery's append() method.

For example:

var t = $("<table cellspacing='0' class='text'></table>");
$.append(t);

You could then populate this table programmatically, if you wished.

This gives you the ability to specify any arbitrary HTML you like, including class names or other attributes, which you might find more concise than using createElement and then setting attributes like cellSpacing and className via JS.

0 votes
Nadira

You can use append (to add at last position of parent) or prepend (to add at fist position of parent):

$('#parent').append('<div>hello</div>');
// or
$('<div>hello</div>').appendTo('#parent');

Alternatively, you can use the .html() or .add() as mentioned in a different answer.

0 votes
Nadira

As of jQuery 1.4 you can pass attributes to a self-closed element like so:

jQuery('<div/>', {
    id: 'some-id',
    "class": 'some-class',
    title: 'now this div has a title!'
}).appendTo('#mySelector');
0 votes
Nadira

All these worked for me,

HTML part:

<div id="targetDIV" style="border: 1px solid Red">
    This text is surrounded by a DIV tag whose id is "targetDIV".
</div>

JavaScript code:

//Way 1: appendTo()
<script type="text/javascript">
    $("<div>hello stackoverflow users</div>").appendTo("#targetDIV"); //appendTo: Append at inside bottom
</script>

//Way 2: prependTo()
<script type="text/javascript">
    $("<div>Hello, Stack Overflow users</div>").prependTo("#targetDIV"); //prependTo: Append at inside top
</script>

//Way 3: html()
<script type="text/javascript">
    $("#targetDIV").html("<div>Hello, Stack Overflow users</div>"); //.html(): Clean HTML inside and append
</script>

//Way 4: append()
<script type="text/javascript">
    $("#targetDIV").append("<div>Hello, Stack Overflow users</div>"); //Same as appendTo
</script>

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