AJAX

[leppie]

Jamie Nordmeyer wrote:

My personal favorite AJAX implementation is one called My Ajax.NET, soon to be called Anthem.NET, and is a completely free implementation. You can find it here: http://jason.diamond.name/weblog/category/my-ajax-dot-net/\[^\]

It has moved to http://anthem-dot-net.sourceforge.net/[^] xacc.ide-0.1.1 released! :) Download and screenshots

[imsathy]

it is there in vs 2005 and the upcoming vs2006.... but can also implement it in vs 2003. the code is not posted back to the server every time so it saves a lot of time retreiving the data and this is done thro xml and javascript either a webservice or a page with script should act as a data layer.

[ppp001]

Thanks, so do you think it is easy to program with ? As it seems need to deal with DOM, xml, javaScript, so many technology together.... And what are the differences in the programming paradigm when compared it to normal client server implementation ? Do it need to take care the many states changing in both the server and the client browser ?....

[ppp001]

Thanks, Is it embedded into the ASP.Net in VS2005 ? or how can I get started to develop with it ? Any good reference for starters ?

[Dario Solera]

NOOOOOOOO!!! AJAX: Asynchronous Javascript And XML ;) ___________________________________ Tozzi is right: Gaia is getting rid of us. My Blog [ITA] - eMule Server .NET

[imsathy]

ya but i dunno much abt it since im workin in vs2003...... i have an app which i developed using this AJAX(it might be useful) if needy how can i post tht to u..... sathy

[Jamie Nordmeyer]

Unfortunately, though, Anthem is still in alpha phase. I've used My Ajax.NET up through version 11, and it's rock solid. I'm looking forward to seeing, though, what he does with Anthem when it's finalized. But thanks for posting the link. :) Kyosa Jamie Nordmeyer - Taekwondo Yi (2nd) Dan Portland, Oregon, USA

[Jamie Nordmeyer]

:laugh::laugh::laugh: D'Oh! You're right. I was pretty tired when I wrote that original reply. Kyosa Jamie Nordmeyer - Taekwondo Yi (2nd) Dan Portland, Oregon, USA

[Jamie Nordmeyer]

My Ajax.NET is extremely easy to use. You can either add the .cs file directly to your project, as it's implemented in a single file, or, if you prefer, or are using something other than C#, you can compile it in to a .dll file, and add a reference in your project to it. From there, calling server functions from your client side is a 2 stop process. First, you need to register your page class with the library, then you need to expose methods for your client script to call. This is done using attributes.

public class MyTestPage : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
// The second param is used to name the class used in your client side code.
// So if you expose a method called GetTable, you'd call it in your Javascript
// like this: Callback.GetTable();
Ajax.Manager.Register(this, "Callback");

  if (!Page.IsPostBack)
  {
     ...
  }

}

// Next, we define our callback methods. They MUST be scoped as public, and you mark
// them using the Ajax.MethodAttribute. If you don't need the values from your server
// controls, mark IncludeControlValuesWithCallBack as false.
[Ajax.Method(IncludeControlValuesWithCallBack = false))]
public int Add(int x, int y)
{
return x + y;
}

// We can return back several object types as well, including DataTable objects.
[Ajax.Method()]
public DataTable GetClientInfo(int clientID)
{
return this.ConnectToDatabaseAndRetrieveData(clientID);
}
}

Second, you just call them from your client side as if they were Javascript functions:

<script language="javascript">
function onSomeButtonClick()
{
var cmb = document.getElementById('cmbClients');
var clientID = cmb.options[cmb.selectedIndex].value;

// Now we call our callback method, whose code is implemented server side.
var dtbl = Callback.GetClientInfo(clientID);

// We can now use our datatable as follows:
for (var i = 0; i < dtbl.Rows.length; i++)
{
alert(dtbl.Rows[0].ClientName + '\n' +
dtbl.Rows[0].Address1 + '\n' +
dtbl.Rows[0].City + '\n' +
dtbl.Rows[0].State + '\n' +
dtbl.Rows[0].ZipCode);
}
}
</script>

Kyosa Jamie Nordmeyer - Taekwondo Yi (2nd) Dan Portland, Oregon, USA

[Jamie Nordmeyer]

I forgot to answer your second question. The differnce between AJAX and traditional web application implementation is that with traditional web apps, when you needed to talk to the server, you did a post back. The web browser would bundle up the value of all controls nested in an HTML FORM element, append those values to an HTTP request, and send that request to the server. Once the server received the request, it would run code written by the page designer to process the sent data. What the server would send back was a full page of HTML markup, forcing the browser back at the client to completely redraw itself. For large forms, this was mostly acceptable. But what if you just needed to update a single control based on the selected value of another? A good example is the sites where you can select a state from a drop down, and another dropdown on the form then populates with the cities in that state. AJAX allows you to avoid posting back the entire form if you want, and allows you to avoid having to redraw the entire page just to update a field or two. With AJAX, if someone changes the state dropdown on the example above, I can, behind the scenes, ask the server for JUST the cities of that state, and it will return it to me in some format set up by the server side developer. Maybe as an XML blob, or a delimted string. Your javascript on the client is responsible for clearing out the cities dropdown, and repopulating it. The user experience is cleaner this way, and closer to what they'd see in a traditional Windows application because only the changing element refreshes; not the whole page. You must be careful, though, to use AJAX only where it's appropriate. You DO NOT want to try and send a 10,000 record datatable to the client, and expect the users of your site to be happy with you as their browser first waits for all the records to come to it, then draws your table. Compiled code is almost always faster than script, so for major operations like a 10,000 record table, do the work server side. Now, as for state changes, since you're not actually refreshing the page when you make a callback, state isn't an issue. If you need to have the current values of your server side controls when you call back, make sure that on the server side, your callback function is attributed as such:

[Ajax.Method()]
public void SumFunc()

Or

[Ajax.Method(IncludeControlValuesWithCallBack = true)]
public void SumFunc()

Kyosa Jamie Nordm

[Kevin McFarlane]

Apart from that MyAjax .NET thing, MS have a tool called Atlas in development. Kevin

[ppp001]

thank so much ! Could you send the app to me via email : shirleylstam@yahoo.com.hk ?

[imsathy]

mailed u the app sathy