YUI Library Home

Site Search (YDN & YUIBlog):

# YUI Library Examples: Dom Collection: Using getXY

# Dom Collection: Using getXY

Clicking the button will use Dom's `getXY` method to get the position of the red element and pass it to the `setXY` method, which will move the blue element to that position.

View example in new window.

## Using getXY

`getXY`, part of the YUI Dom Collection, makes it easy to get an element's position relative to the document.

To illustrate the use of `getXY`, we'll create a `<div>` called `foo` and a `<div>` called `bar`. When the document is clicked, `foo` will move to the top left corner of `bar`.

Start with some simple CSS rules, markup for the demo elements, and a button to trigger the demo:

<style type="text/css"> #foo { background-color:#00f; height:10px; width:10px; } #bar { background-color:#f00; height:100px; width:100px; margin:0 100px 1em; } </style> <div id="foo"></div> <div id="bar"></div> <button id="demo-run">run</button>

Now we will define the function that moves `foo` to the `xy` position of `bar`. The only argument of the `getXY` method is either the ID of an HTMLElement, or an actual HTMLElement object. The `getXY` method returns an array containing two values: `[x, y]` where `x` is the distance from the left edge of the document, and `y` is the distance from the top edge of the document. The YUI Dom Collection provides a `setXY` that accepts an array in the same format.

<script type="text/javascript"> var move = function() { var xy = YAHOO.util.Dom.getXY('bar'); YAHOO.util.Dom.setXY('foo', xy); }; </script>

Next we will use the YUI Event Utility's `on` method to listen for clicks on the button.

YAHOO.util.Event.on('demo-run', 'click', move);

This is a simple example of how to use the `YAHOO.util.Dom.getXY` method. One of the powerful things about this is that regardless of what is influencing the element's position, be it positioning (absolute, relative, etc.), margins, an `offsetParent` (any positioned ancestor), or any other factors that may affect it, `getXY` will return a position in document coordinates (e.g. `[0, 0]` will be the upper left corner of the document).

## Configuration for This Example

You can load the necessary JavaScript and CSS for this example from Yahoo's servers. Click here to load the YUI Dependency Configurator with all of this example's dependencies preconfigured.

### YUI Logger Output:

Note: Logging and debugging is currently turned off for this example.

Reload with logging
and debugging enabled.

### Dom Collection Examples:

- Using setXY
- Using getXY
- Using setStyle
- Using getStyle
- Using hasClass
- Using addClass
- Using removeClass
- Using getElementsByClassName
- Exploring the Dom Collection's API

### More Dom Collection Resources:

- User's Guide (external)
- API Documentation
- Cheat Sheet PDF (external)

Copyright © 2009 Yahoo! Inc. All rights reserved.

Privacy Policy - Terms of Service - Copyright Policy - Job Openings