August 2012
Beginner
583 pages
16h 1m
English
Content preview from Learning PHP, MySQL, JavaScript, and CSS, 2nd EditionBecome an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.
Implementing Ajax via POST Requests
Type in and save the code in Example 17-2 as urlpost.html, but don’t load it into your browser yet.
Example 17-2. urlpost.html
<html><head><title>Ajax Example</title>
</head><body><center />
<h1>Loading a web page into a DIV</h1>
<div id='info'>This sentence will be replaced</div>
<script>
params = "url=oreilly.com"
request = new ajaxRequest()
request.open("POST", "urlpost.php", true)
request.setRequestHeader("Content-type", "application/x-www-form-urlencoded")
request.setRequestHeader("Content-length", params.length)
request.setRequestHeader("Connection", "close")
request.onreadystatechange = function()
{
if (this.readyState == 4)
{
if (this.status == 200)
{
if (this.responseText != null)
{
document.getElementById('info').innerHTML =
this.responseText
}
else alert("Ajax error: No data received")
}
else alert( "Ajax error: " + this.statusText)
}
}
request.send(params)
function ajaxRequest()
{
try
{
var request = new XMLHttpRequest()
}
catch(e1)
{
try
{
request = new ActiveXObject("Msxml2.XMLHTTP")
}
catch(e2)
{
try
{
request = new ActiveXObject("Microsoft.XMLHTTP")
}
catch(e3)
{
request = false
}
}
}
return request
}
</script></body></html>Let’s go through this document line by line, and look at what it
does. The first three lines simply set up an HTML document and display a
heading. The next line creates a <div> with the ID “info,” containing the text “This sentence will be replaced” by default. Later on, the text returned from the Ajax call will ...
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.
Read now
Unlock full access
More than 5,000 organizations count on O’Reilly
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.