Is it a Good Practice to Write HTML Using a StringBuilder in my ASP.NET Codebehind?

I'm interested to hear from other developers their opinion on an approach that I typically take. I have a web application, asp.net 2.0, c#.

What I usually do to write out drop downs, tables, input controls, etc. is in the code behind use StringBuilder and write out something like sb.Append("

I don't find myself using to many .net controls as I typically write out the html in the code behind. When I want to use jQuery or call JavaScript I just put that function call in my sb.Append tag like sb.Append("td...onblur='fnCallJS()'.

I've gotten pretty comfortable with this approach. For data access I use EntitySpaces.

I'm just kind of curious if this sort of approach is horribly wrong, ok depending on the context, good, time to learn 3.0, etc. I'm interested in learning and was just looking for some input.

Edit

After reading the comments here 开发者_如何转开发it sounds like I should take a look at MVC. I've not done that yet. The only hesitancy in doing so is that the existing project is just that, existing. There is a lot of code already done the way I explained and it is hard to imagine what would be involved in changing it, advantages of doing so, and just learning what that would take.

The other thing I'm taking away from the comments is that my code behind should really not include much of the sb.Append code, whereas now it is filled with it in numerous functions. To me it is not messy but that is because I know what each function does and can look at it and see, oh that writes out x, y, and z.

It's not uncommon for me to just have a div on the .aspx part and then build up the .innerHtml of that with the StringBuilder in the code behind.

Thanks again for the comments. I'm thinking as I'm reading them.

I typically write out the html in the code behind.

That part is a little odd, and not something I recommend for webforms. If you want to do that, consider an asp.net mvc project instead.

In webforms, you really want the meat of your html to live with the markup rather than the code. The two should remain separate. You also don't want a huge stringbuilder that encompasses your entire page. This will force you to keep the entire page in memory twice (once for the stringbuilder bytes and once for the built string at the end) rather than writing the page to the response stream as it's built. That means more memory per request, which can really kill scalability.

To those ends, I would abstract distinct portions of your stringbuilder code into custom/user controls that you can use in the aspx markup. These controls can use a stringbuilder to create their output. This means you only need to keep enough html markup in memory to render one control at a time. It also allows you to more easily re-use common markup across pages or even sites.

There are times when you need to generate some HTML in your code behind, but in general, you want to leave the HTML where it belongs, and that's seperated from your code. The VS IDE is a pretty good HTML editor. Use it.

I'm going to go out on a limb and guess you may have come from a "Classic" ASP (vbScript) or PHP background.

My back ground is "Classic ASP" and my first attempts at the Webforms Model were pretty much the same as yours, once I started usnig them and understanding them I've never looked back. There is a disctinct learning curve though in understanding how the page life cycle interacts with the various WebForm controls.

Look up the various threads on ASP.net WebForms vs MCV to see which suits your projects needs the best. MVC Isn't a magic cure-all but in many respects may be more familiar if you're from a "Classic ASP" or PHP backgound.

From a practical perspective, assuming you're sticking with WebForms, if there is the possibility of other developers becoming involved in the project you aim towards using more of the inbuilt controls where you can as that is more than likely what they will be familiar with. Stating the obvious, the more you use the controls the more you will become familiar with what they can and can't do and before to long you will find yourself writing your own controls to fill the gaps or finding existing 3rd party controls.

A big problem you have with that it can get pretty messy... having to escape all the " or messing with carriage returns. Sure YOU can program around that, but what if you want to copy/paste code? sounds like a nightmare and WAY more work than it's worth.

It sounds like you should be writing a custom control and using HtmlTextWriter to write the markup.

Or perhaps more appropriate would be a user control, with markup in the aspx page and anything else in the code behind.

If you're using this approach, you should migrate your development efforts to ASP.Net MVC. Whereas ASP.Net actively tries to abstract the HTML, CSS, JavaScript, etc. away by using web controls, ASP.Net MVC is built around a paradigm of directly controlling the markup itself (though that may arguably be the least of the differences between the two - you should definitely read up on it to at least know the alternatives, even if you stick with ASP.Net in the long run).

Otherwise, what you're doing works if done properly (though you'll be fighting the framework the whole way), though I'd recommend using a StringWriter instead. It uses a StringBuilder internally so the performance characteristics are the same between the two, but the semantics are more consistent with the rest of the .Net framework (e.g., Write vs. Append).

I think this approach kind of defeats the purpose of what webforms was trying to accomplish (separating markup and code).

I know this thread is kind of old and has been answered really well, I just thought I would "append" (pun intended) my answer since I am working with code that was mentioned in the question.

ALL the markup is in the C# classes and they created a StringBuilder object to append all the html and JavaScript strings. This has made it very difficult to read the code and see what's going on, and what if they want to change the markup/design of the front-end? Now, I've got a heck of job on my hands having to go in and refactor all that markup in the classes, when it would be so much easier to change the .aspx pages and connect the data model to those pages.

In my humble opinion, I can't find a good reason to put any markup in your classes/code behind. They are for logic only. Plus, it makes it difficult to test and debug Javascript. That's my two cents. K.