PageMethods or Generic Handler?

Question

I am making a site where users can reply to topics, open topics, etc. and when the user sends a message, I don't want to postback; it's ugly.

I'm using generic handlers right now but I am having some problems with it. Like updating GridView using UpdatePanel when XMLHttpRequest's onreadystate is changing.

I decided to use PageMethods but I also wanted to ask you.

Which is better, faster and more useful: PageMethods or Generic Handlers?

Answer 1

I don't think there would be much difference between the speed of Page methods and HTTP Handlers. However if you're worried about your application's performance, you should benchmark each option and choose what's best for you.

To answer the question, which is better or more useful, basically within the ASP.NET context you have three options, each with their pros and cons:

1. Page methods - all your code is contained in single Page, which is fine if the code is only used by that page. You should probably implement methods that return page-specific HTML snippets as Page methods. However if we are talking about reusable code, such as "Save Topic" or "Get Topics", you might want to consider externalizing this code elsewhere. I guarantee that as your application grows, you'll need those methods elsewhere in your application end as well.

2. Generic HTTP handlers - are lightweight, and great for code you need to call often throughout your application. Most often generic handlers are implemented to serve content, and I don't know what the best practice around this topic is, but to me POST ing to a generic handler to save data has a distinct smell. You'll also find that for related functionality (Save, Get single, Get many, etc.) you'll end up with a swarm of handlers, or a handler with a giant switch statement and a fuzzy contract based on query string and POST parameters. I wouldn't recommend this option to implement extensive AJAX application. For small bits and pieces it might suit your needs.

3. ASP.NET web services (or WCF) - The third option you did not mention in your questions are ASP.NET web services (.asmx). You can easily include them in your existing ASP.NET application without any additional framework dependencies. They offer a good balance between the options 1 and 2. On one hand you get reusability throughout your application, and even outside your application if you so choose, which Page methods cannot provide. On the other hand you can neatly bind together related functionality in meaningful ways, which tends to get messy with generic handlers. You can also interact with the services using SOAP XML, JSON or HTTP POST / Plaintext as needed.

And the wildcard option here is: Use ASP.NET MVC and jQuery. If you're looking to build a lean and mean web application and you generally find postbacks ugly, and you find stuff such as what exactly happens when the xmlhttprequest changes readystate interesting, it might provide you with a better experience overall. Maybe not for this project, but for the next one.