September 2007
Intermediate to advanced
473 pages
10h 7m
English
Content preview from Programming ASP.NET AJAXBecome 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.
Chapter 5. Web Services
In the very first “Hello World” application in Chapter 1, we used a web service to exchange data between a client and server. However, to use web services with JavaScript to their fullest, you need to master some additional skills. These include error handling, inline web services (web service methods in the current .aspx page, also called page methods), and using web services and JavaScript without the help of the .NET Framework.
In this chapter, you will learn some special features of ASP.NET AJAX’s web services support, including error handling and maintaining session state. You will also see how to use non-ASP.NET web services with JavaScript.
Error Handling
Up to now, when working with web services, we expected our remote calls to work each time. However, the fact that an exception could be thrown has not yet been considered.
When using web services from remote servers (which, for the purposes of this dicussion means servers on another domain), developers often do not include exception-handling code. One reason is that a web service can be implemented with any technology, and every technology has its own way of running exceptions. Some do not raise exceptions at all.
However in the case of ASP.NET AJAX and Ajax, using web services is a bit different. We cannot directly use a remote service, since the security model prohibits us from doing so. By default, JavaScript and the XMLHttpRequest object only allow access to URIs within the same domain as the current ...
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.