How can ASP.NET generate HTML5 code? - asp.net

I'm feeling a bit lost with my question about HTML5 code generation, and despite having put some efforts into my research I don't really feel much wiser.
I use VS2010 for the creation of ASP.NET pages, and I do know that there is an (unofficial) "Web Standards Update" for VS2010 SP1. Using this update I can change the settings of the "Target Schema for Validation" in the ASPX editor window to HTML5. The new elements / tags and semantics are then available via Intellisense, and I can nicely code away manually using all the fancy new stuff.
What I don't understand is how to get something like the ASP.NET controls to generate HTML5 code (where it makes sense). Is this at all possible or am I completely going in the wrong direction here? I would have expected that I do not have to "hand code" HTML5 as long as I use the existing controls (which tend to generate a lot of JavaScript in the background when the page is delivered to the client's browser).
Thanks in advance for a clarifying answer
G.

Some controls generate slightly different dialects of HTML based on the particular User-Agent. However, not all of them know about HTML 5 yet, and there's no specific property to enable HTML 5 generation, just as there isn't a property to enable other dialects of HTML.
If you want to generate HTML 5, you can do one of three things:
Create a new control that overrides the existing one, and either use it directly or replace the original with it everywhere in your app with tag mapping
Create a control adapter and modify the control's output as it's generated
Create a custom control

The controls you are referring in ASP.NET are what is commonly known as "webforms". They are basically server side controls that generates the javascript code needed to postback the data to the server, mantain the state of the controls between postbacks, and stuff like that. As you said, those controls generate too much code and a excessive number of roundtrips to the server, so it is not very recommended to use webforms.
HTML5 is mainly client side, so it has very little to do with the webforms server controls. It's a different approach than the old ASP.NET webforms. Because of this, ASP.NET is including on its newer versions the MVC framework, the razor engine, JQuery and another javascriprt libraries. MVC includes some helper classes and templates that helps you generating the client code, and many other features to support HTML5 enabled webs. So, I would recommend to start reading about it.
Anyway, now that jquery is fully integrated in Visual Studio, javascript coding is not so difficult.

Related

Why can't I use server controls in ASP.net MVC?

I'm getting ready to be responsible for leading the development of a small ASP.net MVC application. This is my first time creating an MVC application, so I am excited!
I've carefully read over the documentation and I feel like I have the general idea of how MVC works. However, if I understand correctly, server controls (like GridView, for instance) are not part of MVC.
My question is: Why? At my development shop, I'm so used to using controls like GridView and the MS Chart Controls that I'm almost at a complete loss as to developing without them. It seems almost like starting over.
Why are the server controls unavailable? How does Microsoft expect me to work without them? What are the alternatives?
My question is: Why?
Because most of them depend on things like ViewState and the Postback models which are part of the classic WebForms model and no longer exist in ASP.NET MVC. Those server side controls rely on events that will perform postbacks to the server persisting their state in hidden fields (ViewState). In ASP.NET MVC you no longer work with events such as Button1_Click. In ASP.NET MVC you work with a Model, a Controller and View. The Controller is responsible for receiving user requests, querying the Model, translating the results into a view model and passing this view model to the View whose responsibility is to display it under some form.
In ASP.NET MVC there are HTML helpers that could be used to generate some reusable HTML fragments between views. You may take a look for example at the Telerik ASP.NET MVC suite of such helpers. They call them controls but they have nothing to do with classic WebForms server side controls. They are just HTML helpers.
Basically classic WebForms are a leaky abstraction of the web. What Microsoft did back in the time when they designed this framework was to bring existing Windows developer skills to the web which was getting more and more momentum. But since the web was still a new technology that most developers weren't yet familiar with, they created this abstraction to hide away the way that the www works. Those developers were accustomed to drag and dropping controls on their Windows Forms, double clicking on buttons that was generating some code for them in which they put their data access logic and so on. This model was transposed to web application development thanks to WebForms. The HTTP protocol was successfully hidden behind this abstraction called WebForms. For example you don't need to know HTML, nor Javascript, not even CSS in order to create a website using WebForms which is really great because the framework abstracts all those things for you. Unfortunately by doing so it prevents you from easily utilizing the full power of lower level web technologies which some people might need when developing web applications.
What ASP.NET MVC does is basically remove this leaky abstraction and bring the www to the developers the way it was intended to be by its creators. ASP.NET MVC is not mature enough compared to classic WebForms so you cannot expect to find the same range of available controls and widgets but things are slowly shifting.
I would recommend you start here with ASP.NET MVC: http://asp.net/mvc. Go ahead, watch the videos, play around with the samples and see if ASP.NET MVC is for you or not. And of course if you encounter some specific difficulty or question don't hesitate to come back here and ask it.
I'm so used to using controls like GridView and the MS Chart Controls that I'm almost at a complete loss as to developing without them. It seems almost like starting over.
In this case, starting over is good.
I've gone through a similar journey. If straight HTML scares you, try working with the System.Web.UI.HtmlControls namespace. This will allow you access to standard HTML controls, but you'll still have the comfort of turning them into server controls if you need to (either by specifying the runat="server" attribute, or by converting them into equivalent ASP.NET controls.
In addition to Darin's answer, there's another problem with ASP.NET: you're bound to Microsoft's view of the web. That GridView you love? It's generating bad HTML. The Paging controls it provides? Even worse. Even if you know very little about HTML compliance, nested tables should give you the chills. In a way, everyone who uses a GridView is lucky that legacy web supported by Microsoft (and to a lesser degree, Google and Mozilla) came from such a god awful starting point.
Finally, to summarize: my suggestion is that you try to rewrite your pages or develop new web applications (as best as you can) using HtmlControls only. You'll probably have to learn some JavaScript/jQuery, and might have to venture into the world of AJAX to make your controls operate the way you want them to.
Use this as a stepping stone into the world of MVC. You won't use the same technologies (and may drop a lot of JavaScript/jQuery), but it will help you change the way you think about web development in much smaller, and perhaps easier-to-absorb chunks.
Ultimately, however much you like your ASP.NET controls, you'll have a much greater degree of freedom, and you'll also be developing websites that make use of newer technologies, which will provide added value to your websites.
At the core of this is Model View Controller (MVC) which promotes decoupling. The idea is that you feed your View (web page) a Model with all the data that it needs to be rendered. Server controls are tightly coupled. There is no concept of state in MVC or 'should' be no concept anyways.
That's kind of the point of MVC. It takes away the high level of UI abstraction that server controls provided and leaves you with html and javascript. (It also adds some really cool model binding features)
I am new to MVC and have found using Partial Views to be similar in creating small, reusable UI elements that do not fit into the _Layout. For example, sliders, slideshows, navigation, featured sections although you can use #section for this I find partial views to be more beneficial. This concept enables me to create reusable libraries that I can switch out easily and use in other projects. To me this is similar to controls, although there is a debate both for and against this analogy.

Customizing asp.net webforms markup

I'm a new comer to the asp.net world. I hear a lot about asp.net mvc and it's advantage over webforms about the ability to customize the markup and css. I also heard that asp.net is much easier to learn than asp.net mvc so I decided to go for asp.net and webforms. My question is: what's the level of customization a web developer/designer can get with webforms concerning the markup and css?
You can have as much customisation as you like in the html output! You can customise everything in web forms. However, with customisation brings time, effort and room for error. All of these things is what web forms is trying to save you.
However, since you are just starting out I wouldn't worry. Just make your web forms how you want and forget the customisation of output (it is much better with ASP.NET 4 anyway). In a few years when you are more experienced then worry.
If you were going to customise everything then you should have gone with ASP.NET MVC - it is one of its main arguments. But there is nothing wrong with web forms. Particularly if you are beginning with asp.net in general I'd say it is better.
Standard ASP.NET WebForms uses server controls that generate the markup for you, so the level of customization is limited to what the controls you are using provide. There are techniques that allow you to override what is rendered by the controls and thus customize the markup and also write your own controls but it requires some coding. It is possible to achieve almost complete customization of the markup but it IMHO requires more efforts than a web developer should need to put into something like this.
While it is definitely possible to have a SEO friendly, unit-testable, maintanable, standards compliant application using classic ASP.NET WebForms, the efforts it requires will be significant compared to ASP.NET MVC. But if you don't care about those things you will be able to pretty quickly develop web applications.
ASP.NET comes with a set of built in user controls - things like text areas, buttons etc. These mimic winforms in how they are supposed to work (events etc), however this is a rather leaky abstraction (you must always remember you are working with HTML and HTTP).
The user controls allow reuse and when a page is built they emit HTML - you have little control over the emitted HTML (unless you override the rendering, which kinda defeats the point), hence the perception that they are harder to customize. It is not easy to get right either and requires more work than I think is worth.
There are also different compromises in the way pages are rendered out (ids for example end up as a long string of concatenated container control names) which make MVC a better choice if you are looking for control over your HTML.
Microsoft suggests that you pick the technology based on your needs:
While ASP.NET offers rich controls and produces quick results without great control over the markup (as mentioned: it can be done but somehow beats the idea behind ASP.NET and creates a lot of additional code), it suffers from the flaws mentioned by the other posters.
In MVC, there is a limited set of "out-of-the-box" controls and you'll have to code more on your own (including clientside JavaScript) but you do have more control over the rendered markup of your controls. In addition to that, your project will generally have a clean separation of concerns which benefits (unit) testing and maintainance.
Another aspect that hasn't been mentioned yet: In ASP.NET a page undergoes the so-called "ASP.NET Lifecycle" every time the client communicates with the server. The Lifecycle consists of several events that are fired in a special (and sometimes confusing) order. Handling those event in the right order in complex web applications is one of the biggest difficulties in ASP.NET and often leads beginners to forfeit. In MVC you don't have to deal with that kind of problem.
Therefore I strongly recommend that you take a look at the ASP.NET architecture before you start to code. Here is a very basic start: http://www.asp.net/learn/videos/video-6558.aspx
Personally, I started with WebForms and am now moving to MVC after I worked with the similar MVVM pattern in Silverlight and WPF for my bachelor thesis. This kind of did it for me so that I now understand the benefits and ideas behind MVC a lot better. Once you are used to WebForms, switching won't be that easy though.

Are Visual Studio web projects Web Standard friendly?

I'm struggling with a few in-house developers that are creating some web apps in VS 2008 using C#.
It appears that the native tools and components in VS 2008 are not being nice about creating Web Standard code.
For example, the navigation component creates items in its own table structure.
Is there anyway to make a web project from Visual Studio create nice, clean, browser friendly code?
You can use CSS Friendly Control Adapters to alter the output of the current ASP.NET controls. It's easy to set up and you don't have to change any existing source code.
If you're bound to ASP.NET WinForms, you could create you own set of controls or use 3rd party controls. There is also a XHTML configuration setting you could set to Strict, so that the controls try to render more valid core.
When you really want to write nice, clean, browser friendly code, you could take a look at ASP.NET MVC. ASP.NET MVC gives you complete control of the output, but that means you have to do all the things WinForms currently does for you, yourself...
Certainly. If a component doesn't produce markup you like, then you don't use it. It's just that simple.
Having said that, be sure to check out Visual Studio 2010 beta 1 to see if your issues have been addressed. If they haven't, then you get to complain about them in a way that might get them fixed.
VS 2008 web projects don't do anything web-standards-unfriendly. The standard ASP.NET controls (like the menu control you mentioned)? That's another story -- some use a mess of tables and javascript to do their thing.
The good news? You can use what you want of ASP.NET without having to use those controls if you don't want to.
Go MVC !!! you will have complete controle over your UI
My two cents: machine-generated code is almost never as standards-compliant as the code I write by hand, especially when you get into fancy widgets and whatnot. The obvious trade off is that writing code by hand can be tedious and time-consuming.
We've come a long ways since the dark ages of code-junk that frontpage or dreamweaver used to spit out, but even still...
In the end, your code is only ever as good as your programmers.
The Web Projects themselves are simply containers for the code that you create and a mechanism for managing and building the compiled project.
Based on my experience, the controls generated by VS comply to web standards ... that being said, browsers differ on which standards they do or do not enforce and how they enforce them. For the most part, you have a high level of control of the HTML that is output from your page. The table structure generted by the navigation control id valid HTML - you may be wanting to avoid the use of tables in which case, that particular control might not be for you.
For the most part, when you have a complex control you will need to take what you get - the HTML that is generated may not be intuitive to you and your team but that is often the price paid for the time savings gained by using a pre-built control, particularly one that is intended to service the needs of a wide variety of uses. (The same can be said for most code/script libraries you use/buy/find)
Many controls offer templating that provides you with the ability to define a template for how the resultant HTML is generated.
If you want cleaner markup, you have a few options:
a) Check out the CSS Friendly control adapters from codeplex. They help alot with certain controls.
b) Avoid the more complex server controls. There is very little one can't do nearly as effectively with a repeater and some user controls that one can't do with most any databound control for instance.
c) Try ASP.NET MVC. No neato server controls to do UI lifting, but it will let you make very, very clean UIs.

What are the benefits of an XML data model over the DataSet model?

At my current job we have a CMS system that is .NET/SQL Server based. While customizing a couple of the modules for some internal use, I was a little surprised to see that instead of having APIs that returned data via your typical result set that was bound to a DataGrid/DataList/Repeater control, that the APIs returned an XML node/collection, that was then passed to an XSLT transformation and rendered on the page that way.
What are the benefits to using a model like this?
Using XSLT transformations would enable you to use a different layout and formatting than the standard .Net grid controls. Some people don't approve of using the .Net grids because they can include more HTML than necessary, and because if not managed carefully, they can bloat ViewState.
There was a recent discussion here about the .Net grids being bloatware (but developers use them anyway).
The outputted pages can be of any type, like html, php, etc.
By setting up the datasource and xml that the page merely transforms, you have also instantly created a simple 'web service' that can be consumed by other software. For example, it would be trivial to turn that grid into an rss feed or write a program to scrape that data periodically and send a more pressing alert.
The XSLT method is very MVC, unit-testing, separate-concerns friendly where ASP.NET controls well... aren't.
caveat: I reject the assumption that MS can write better html/css/js than I can. ASP.NET controls are clunky abominations.

Can ASP.NET pages be as "lively" as a page done with just HTML?

I've never created a web page and I'm just learning ASP.NET now and all the examples I see are mostly with filling out forms etc. So I'm wondering if the lively, colorful, and snazzy web sites can be done with ASP.NET. I have also been playing with a trial of Expression Web. It seems to be for the "fancier" side of things. Are the two sides of the web mutually exclusive or can an ASP.NET page be just as colorful? Keep in mind I'm new to doing anything on the web.
Thanks for your help?
Yes, you can make an ASP.NET page look just like a static web page. The look and feel of a web page is done completely on the client side, using HTML, Javascript and CSS. ASP.NET lets you use all of these things, but it provides the ability to generate output to the page on the server side before sending it to the client's browser. Once it gets to the browser, the HTML, Javascript and CSS will apply just as if the client was loading a static page.
Absolutely yes!
You may be confused with the tutorials which are focused on teaching backside technology and poor on page design. Isn't microsoft.com colourful enough?
Asp .Net just outputs html.
ASP.NET is simply a web application framework. What is sent to the browser is *usually** HTML, so anything that you can do with a static HTML page, you can do with ASP.NET.
In my personal experience, I have had better luck with producing "lively" pages using ASP.NET MVC, since I have better control over the markup, and I don't have to contend with ViewState or munged control IDs. Subjectively, the pages feel less sluggish than those of ASP.NET, and I can use JQuery to improve the user experience.
Yes you can, just do not use Web Controls. I have written several Blogs on this so far this year. http://professionalaspnet.com/archive/tags/Thin+ASP/default.aspx
Ultimately, html is sent to the browser irrespective of the server side technology, so question is a bit awkward.
But for aesthetics side, asp.net provides features called master pages, themes, skins. By providing these it goes beyond css.
ASP.NET can be used to produce very lively and colourful pages, but you need to understand how to create the pizzaz. Mostly that's going to be media and javascript. For that, you need to understand HTML, and then what the ASP.NET Server controls render as in HTML so that you can control and manipulate it in your javascript more easily.
The reason that ASP.NET tutorials feature data and forms is that the need to manage data (and dynamic content deriving from it) is what makes people use ASP.NET rather than static html.

Resources