I was wondering, whats the best way to handle common HTML controls in ASP.NET? I mean, ASP.NET server controls generate too much crap inside the code so I rather use common controls.
But how about databind and how to manage those common objects correctly (such as combobox, textbox and so on)?
Don't forget that you can always set runat="server" on any control - that includes standard html form controls such as <input> and <select>, and also other elements like <div>. Anything, really.
This means that you can regain control of the html output in your WebForms pages quite effortlessly - as long as you don't need viewstate or any other more advanced databinding/state managing that ASP.NET normally handles for you.
That said, learning to use the ASP.NET MVC Framework is not a bad idea, since it helps you regain control of much more than just the html output. Generally, creating a page in ASP.NET MVC takes a little more work, since there are no drag-n-drop controls like gridview, textbox or even repeater. Instead, you use html helper methods and regular foreach loops, which means you have to type a lot more code. However, the MVC framework is designed so that you won't have to repeat much code anyway.
If you're concerned about the html markup generated by the WebForms ASP.NET engine, i suggest you take a look at ASP.NET MVC. It's purpose is specifically to give you the control you need over the generated html.
If you don't want to start learning ASP.NET MVC, ASP.NET 4.0 WebForms gives you more flexibility in the generated HTML (such as enabling the ViewState for a specific control only, setting the html id's etc.).
As for the databinding, again if you study MVC in depth and start thinking in terms of action -> result you can gain a lot more control and flexibility.
Later edit: I forgot to mention Razor, the new ViewEngine under development at microsoft. It's currently in beta and only inside WebMatrix, a very stripped down 'getting-started type' development platform for ASP.NET. MVC combined with the very clean code you can write using Razor will be in my opinion an important trend-setter in the web development world.
There's a reason ASP.Net controls generate all that "crap". It's so you can databind and manage those objects correctly. Using standard html controls is useful when you don't need direct databinding or if you have no need to manipulate the control through server-side code.
The best way to handle common HTML controls in ASP.Net is not to handle them directly. By using them to handle data and functionality, you're basically neutering .Net. You might as well go back to classic ASP.
Related
We have an ASP.Net ScriptControl that is shared between web app projects. One project is being converted to MVC 3 and the shared control needs to be used but of course MVC doesn't have controls or view state.
My ideal solution would be to wrap the control in a html helper so it can be placed on the view. Then, I can send/receive data to/from the control inside the helper.
Is it possible AND is it decently trivial to do so?
As long as it doesn't rely on ViewState or Postback, yes, you usually can.
To be safe in this scenario I would include an ASPX page in your solution rather than attempting to hack it to work. It 'can' work - at times but behavior can be buggy depending what it is looking for behind the scenes so it can be a hack.
I am currently working with ASP.NET and the person who designed the form has used all Server Controls for things like TextBoxes and Dropdowns etc when really they are not providing postbacks.. Some of the dropdowns and textboxes are values that I need only in jQuery so as far as I can see there are no drawbacks to coverting these controls to standard html controls rather than ASP.NET server controls?
I suppose I will need to continue to have my GetDataGrid button as a server control because I will need it to postback (and receive PageLoad events etc - all asp.net events) to update the GridView? Or would it be possible to use the GridView (ASP.NET server control) from a Webmethod and call it via Jquery?
Of course in my webmethod I would need to the instance of the gridview to add the datasource - but I don't see how this would be possible without being in the ASP.NET events - or maybe I wrong?
The other thing I thought of was changing the GetGridView button to a standard HTML and calling the javascript postback from the client click event?? This way it would do a real postback and I would end up in Page_load.
Taking everything into effect i don't want to the change the GridView asp.net control as it funcions well as an asp.net server control but i am unsure how i would do this.
I remember a document being available that said "how to use asp.net webforms without server controls" but i can't seem to find it. I suppose using webforms like asp.net MVC - but i can't change the project to MVC - its out of my control.
I would love to hear some feedback with regards to how to do this or comments etc.
I find ASP.NET webforms to inject a lot of code smell into pages - I am using .NET 3.5 so a lot of the output is with tables etc...
If you use Request.Form["..."] then you can get the information which was filled in in standard html input fields.
Instead of keep on using the GridView control I suggest you take a look at either jqGrid or the new templating system that Microsoft put into place for jQuery (currently a plugin but expected to be part of core jQuery from version 1.5 on). These can bound to json which can be retrieved from a webmethod or pagemethod call to fill up the template with data.
Also i don't think its possible from asp.net (code behind) to receive values of an html >control without it having runat=server.
Use webmethods.
Set a client event (like 'onchange') on the html control and then in javascript function called when the event is fired you can use PageMethods to send your data to the code behind.
Some thoughts...
The GridView can't be created in a WebMethod and even if there was a way to get that to work, you'd be better off going with a genuine client side grid. As that's not an option, I don't think there is too much point in trying to make any major changes to your existing pages.
ViewState
Changing the textboxes, buttons etc to HTML versions, would gain you a little bit in reduced Viewstate size but add a bit of complexity in how you handle interactions with the page. You can add runat="server" to HTML controls which will give you control over what is rendered and still have access to the control on the server side.
.Net 4 gives you far more control over viewstate but unfortunately in 3.5 its not as easy.
The GridViews
You could wrap the GridViews in UpdatePanels. That's a 'cheap' way to add some interactivity to your pages although you won't be gaining anything in terms of performance.
It's also still possible to manipulate the Gridview using jQuery on the client-side. There a lots of tutorials, blog posts etc explaining how to do this on the Internet.
MVC with Webforms
Its also possible to mix ASP.Net MVC with Webforms in the same website. As it sounds like you are familiar weith MVC, you might want to consider this approach for any new pages. Here's a blog post explaining how to do this.
Update:
Here's a more recent article by Scott Hanselman on how to use MVC with an existing Webforms application.
We are plannning to use Ajax in our ASP.net project. However, we still want the member panel of our web site to work in all browsers. We have decided not to use Ajax in some forms where browser independence is must.
I am now confused with whether we should use ASP.NET controls or HTML controls or both?
I have two questions:
Are there any problems that I might face using either of approach?
Also which one is better considering efficiency and performance?
The Asp.Net Controls including the ajax controls are independent of browsers, asp.net will detect your browser and try to render the best html/javascript for that browser. So you are good with server controls.
If you are going to implement the project in asp.net then for all the controls that need to be accessed via code at server side needs to be asp.net controls. Those controls that are static and only displaying some value can be html controls.
The main point is that the asp.net controls are rendered to html controls... so the client who views the web-page actually gets the html controls.
For AJAX refer this
ASP controls and HTML controls as complementary.
ASP controls bring facilities for programming like the viewstate (the control keeps its content after a post back), the binding with datatable, and a lot of presentation properties. It is really an advantage in terms of time and maintainability to use these controls. They also manage some security feature like html code injection. ASP controls could be controled and managed from the code behind page.
HTML controls are out of the native ASP.NET page process. It is sometime a good thing to have particular control that you don't want ASP.NET take in charge and modify, but it is not the core of an ASP.NET web application.
If you can use HTML - it is always better - as it is much faster.
The use of ASP controls should work on all browsers as far as I know, but it less efficient.
Better create a small example and test it on some browsers before you decide.
(I've used ajax on both explorer and Firefox and it works)
I have looked around on the Internet trying to answer this question. It seems to be kind of complicated though! Seems to come up with all sorts of different topics such as the HtmlHelper and other stuff.
Basically. How can you use custom controls with MVC? In a way that avoids doing anything that is frowned upon.
Also, Is it true that with MVC you have to put some simple logic IN THE PAGE? Isn't that what we should be getting away from?
Update: So, Seems you cannot use controls which depend on anything which MVC does away with, such as the postback events and viewstate. Can you make your own then? A control which does only rendering of course.
Can you use ASP.NET controls? Maybe. If the control does not use ViewState or postback events, it will probably work. For example, the LoginView control works just fine. Telerik supports ASP.NET MVC with some of their controls. On the other hand, if the control needs either ViewState or postbacks, then it just isn't going to work. Controls with data binding aren't ideal, since you typically have to use code behind him up. But they will work, if you add code behind.
On the other hand, controls with no knowledge of ASP.NET (such as the jQuery UI controls) work very well.
No, you don't have to put your logic in the page. You just don't put it on a code behind page, either. Instead, use helper methods.
With respect to the second question, the page is exactly where view logic should go. Any other logic should be in your controllers or models.
I'm not sure what you mean by custom controls. You can have ViewUserControls that are rendered via partials to reuse view code. If you are talking about 3rd part controls built for webforms, it's likely they won't work -- at least for awhile. If you absolutely must have them, though, there are ways to mix MVC with traditional webforms in the same site.
Are there some things I cannot do with ASP.NET MVC?
Things that are only possible with ASP.NET WebForms,
or extremely much easier with WebForms?
We consider using ASP.NET MVC for a new project.
But I wonder if there are some obvious things we will not be able to do with ASP.NET MVC when compared to WebForms, or places where we will have to spend a lot of time with ASP.NET MVC.
The biggest one would be using existing 3rd party controls on your form. Most of the inbuilt controls are pretty easy to reproduce, but if you have a pet 3rd party control, you might have to host that on a regular (non-MVC) aspx page (luckliy this is supported).
Likewise, "web parts"
Also - the feature where ASP.NET uses different html for different clients (mobile, etc) becomes... different; you wouldn't want to do this by hand, but in reality most clients now work with standard html, so it is less of an issue in the first place.
Some things like i18n via resx files need extra work than is in the vanilla MVC template, but the samples are there on the internet.
One point... MVC is licensed only for MS/ASP.NET; so one thing you can't do (without violating the terms, as I understand it) is to run it in mono/Apache - but IANAL.
Now consider the things you can do with MVC, that you can't (or are hard) with vanilla:
routes instead of pages
automated input resolution (action arguments)
proper html control...
...enabling jQuery etc for simple AJAX
separation of concerns
testability
IoC/DI
multiple templating options (not just aspx/ascx)
re input resolution:
public ActionResult Show(string name, int? page, int? pageSize) {...}
will pick "name", "page" and "pageSize" off (any of) the route, query-string or form - so you don't have to spend lots of time picking out request values.
re templates - aspx/ascx aren't the only templating options. For example, see here; or you can write your own if you like... The view is not tied to ASP.NET controls at all.
Validation is not as easy as in WebForms. In Webforms you can add a validator and just set a property that enables clientside validation. You can localize the errormessage. The localization works clientside and serverside.
There is no out of the box clientside validation in MVC and you need to find a way to localize clientside errormessages.
Localization itself is different. Ressources obviously by default dont exist per page, because there is no page. But there is a good way to have ressources per view.
I still did not check, if it is possible to set SSL-required per folder.
EDIT
The story is different with MVC3. There is a good validation support now.
There are still things that are not implemented in MVC. The biggest issue for me is a complete implementation for donut cashing and partial cashing. There is some improvement in MVC3 in this area but it is still not complete. Anyway stay tuned: the MVC team seams to be aware that this is something they should work on.
The big one is Controls. User Controls are not available with ASP.NET MVC. I have even gone so far as to try using code like this:
new Label().RenderControl(...ResponseStream...);
No dice.
Of course, as a part of that, there is no need for view state, so that isn't in there.
Server controls do work, though.
As Marc said, third party tools and (serverside) webcontrols cannot be used. So slapping something together quickly by dragging and dropping a few controls on a form (like a grid and a dataaccess control) is no longer an option.
But with the codegeneration etc. you can still make something quickly. And you still have the above option if you need something quick.
I think view-state is non existent in MVC. You will have to track your own view state in some other way than the built in view-state in non MVC projects.
EDIT:
According to comments: "Getting rid of ViewState is an advantage not a disadvantage". – Craig
ASP.NET Ajax is not working with ASP.NET MVC so no UpdatePanel (due to lack of postback). Fortunately there is built-in ajax (Ajax.Form) which can be used to perform partial updates not to mention jQuery which is shipped by default with the Visual Studio project template.