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Archive for January, 2009

jQuery plugin : jqPageFlow – scrolling pagination made easy

January 18, 2009 26 comments

jqPageFlow

Simply put, this plugin makes the scrolling pagination found on sites like dzone.com and Google Reader easy to implement on your site.

A working demo is viewable here

This is of course all configurable, and intended to be used on an automatically generated page using a backend script (eg php).

Please note that this script is still currently in beta, so if you find any problems please post a bug submission to http://code.google.com/p/flexidev/issues/ with as much information as possible

Usage

  1. Download the latest source code from the repository : http://code.google.com/p/flexidev/downloads
  2. Include the jQuery library into your page header (this plugin supports both jQuery v1.2.6 and v1.3)
  3. Include the jquery.jqpageflow.js file into your page header
  4. Include the supplied css file in your page header : modify as you see fit
  5. View the source of this page: copy, paste and modify the javascript block as required. Use $(“body”).jqpageflow(); to use defaults.
  6. Create a php/.net/perl/python etc backend script to handle the serverside stuff – see the index.php file (this page) included in the download source for a basic example

Features

  • Compatable with jQuery v1.2.6 and 1.3
  • Chainable
  • Configurable options : including the url to call, current page, pager var, container element etc
  • Server side platform independant : tell it how to interact with your backend scripts
  • Cross browser compatability, tested in FF 2.5+, Safari 3+ (more browsers to come soon)
  • Skinnable loader with CSS and customizable image path

Options

  • url: Specify which url (relative or absolute) the plugin should submit the ajax request to. Defaults to current window.location
  • currentPage: Gets appended to url as a GET value to help your backend script keep track of which page of results the user is on. Defaults to 0 (first page)
  • pagerVar: Related to currentPage, gets appended to url as a GET var to help your backend script keep track of which page of results the user is on (e.g. index.php?page=2). Defaults to “p”
  • perPage: Used for calculation and display purposes, tell the plugin how many results are being displayed per page. Defaults to 50.
  • totalResults: Tells the plugin when it needs to stop trying to look for more results. Defaults to 100
  • container: Specify which html element contains the result items, can be any jQuery compatible selector (eg “#mycontainer”, “.results”, “body”).
    Any html returned to the ajax call gets appended to this element. Defaults to “body”
  • loaderImgPath: Tell the plugin where to find the loader img relative to the page calling the plugin. Defaults to “images/loader.gif”
  • debug: When set to 1, the plugin will print debugging information to the console (firebug). Defaults to 0

Changelog

  • 18 Jan 2009 : version 0.1b released

Credits

How to use jQuery to select a radio button from parent element

January 9, 2009 4 comments

A friend asked me for some help on doing the following :
1. You have an unordered list – within each list item you have a radio input.
2. When you click on the list item (i.e. the entire container), it must a) select the radio input and b) add a css classname of “selected” to the list item.

You can find a demo here.

First, the html :

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
<head>
	<!-- include our jquery scripts -->
    <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.2.6/jquery.min.js" type="text/javascript"></script>
    <script src="js/radio.js" type="text/javascript"></script>
    <style type="text/css">
    	li { color: #000; }
    	li.selected { color: #FF0000; }
    </style>
</head>
<body>
	<div>
		<ul>
			<li class="test">Test 1 <input type="radio" name="test" /></li>
			<li class="test">Test 2 <input type="radio" name="test" /></li>
			<li class="test">Test 3 <input type="radio" name="test" /></li>
			<li class="test">Test 4 <input type="radio" name="test" /></li>
			<li class="test">Test 5 <input type="radio" name="test" /></li>
		</ul>
	</div>
</body>
</html>

There is nothing out of the ordinary here – just a simple unordered list of radio inputs.

Next, the js (radio.js) :

$(document).ready(function(){
	$('li').click( function(){
		$('li.selected').removeClass('selected');
		$(this).addClass('selected');
		$(this).children("input[type=radio]").click();
	});
});

1. First – we tell jQuery to execute the following code once the document has finished loading, ensuring that the DOM has been registered successfully.
2. Next we bind a click event to all list item elements on the page – you can of course change this to all list items with a class of “myselection” for example ( $(“li.myselection”).click… )
3. When a list item is clicked – we first need to remove the “selected” class from all other list items.
4. Now we need to add the “selected” class to the list item which fired the event ( $(this) ).
5. Finally, we need to make sure that the radio button inside the list item is “clicked” : we do this by using the .children() selector and executing a click() event on the input.

The important bit is the $(this).children(“input[type=radio]”) selector. What we’re doing here is telling jQuery to find all inputs of type radio (i.e. all radio inputs) inside “this” list item (i.e. the list item which was clicked on). We then use .click() to..as you guessed it… execute a click event on the returned element (in this case the radio input).

And that’s all there is to it. You can read up some more on jQuery selectors here.
I would also highly recommend reading the following article : Improve your jQuery – 25 excellent tips.