1) Yes it is common to use Ajax and Asp.net on the same website. I do it all the time(in fact if you turn off javascript on my sites they won't work too well as so much is AJAX). AJAX allows for requests to the server to be made without refreshing the page you still need a serverside language to do stuff with that request. You also need the load the page for the first time so asp.net controls still are needed and in fact if your using asp.net ajax then you can use update panels where you put controls into that automatically become ajax enabled.
2) I am not sure what you mean but Ajax is mostly javascript so it lives on the client side and sends requests to the server side.
Edit
Ok I skimmed most of the stuff in those chapters. AJAX server side is where most of the rendering is done on the server side. So the update panel is an ajax server side control. You drag it on to your webform throw some other server side controls into it and a button. If a user then clicks on that button in the update panel an ajax request is made to the server and you can grab all the stuff you need and use C# to change it. You never have to write one line of javascript code to make that happen.
Of course that has a price though for instance an update panel does not do a true ajax request because of the page life cycle. If you actually watch the code through the debugger you will notice it will go through the page life cycle but in the end will just rerender that update panel so there is a bit more over head then if you did it yourself.
Client side Ajax is basically Microsoft trying to make it easier for you to do javascript by trying to make it more like C# syntax and giving you built in methods. A problem is that alot of people throw the buzz word Ajax too often around and call stuff that should not be called Ajax when it should be just called javascript.
This seems to be the case with this client side ajax as most of what I seen in the client side ajax chapter is almost all javascript. Like in "Figure 33.8. Selecting a menu item." all it seems to be is your click on a choose then it displays the name of that button that is not really Ajax.
Ajax to me is when you actually make a server request to post or get some information with out the page refreshing(ie full post back). For example if you got a form of data that you want to send to the server to be saved in a database. If you would hit the save button and that form data would be sent to the server without the page refreshing then that would be an Ajax request.
Most of the stuff in the ajax tool kit is more javascript
http://www.asp.net/ajax/ajaxcontroltoolkit/Samples/Calendar/Calendar.aspx
For instance the calendar control to make it select different dates it is not doing any sort of request to the server since it is all javascript so why would it be ajax if it never posts to the server?
If you would take the value in the textbox that the calendar control puts the date in and post it to the server without refreshing the page that would be an Ajax request.
Finally I would not be too worried about asp.net webforms going anywhere anytime soon. I believe the guy who wrote that article about asp.net going to dye is the guy who made Ajax or was involved some how with the development of Ajax so he is probably biased.
Besides look its been 5 years now since he posted that and asp.net is stronger then ever. Ajax still needs a server to connect to, you still need to render the initial page load with either straight html or asp.net server controls.
Edit 2
1) Yes I think jquery is better the MS ajax for a couple reasons:
- It uses less resources then drag and
drop controls
- It simplifies javascript alot as it
makes it easier to use(such as
selecting html controls,etc). So if
I was using MS ajax I probably still
be using jquery for the selectors it
has so it is kinda redundant to use
both unless you have a good reason
too.
The only problem is that it can be a bit trickery to do ajax request using jquery when using asp.net webforms(asp.net mvc was designed with frameworks like jquery in mind so it is easier to do).
2) You really only need to learn jquery and not even javascript. I read a javascript book in like a day then jumped into jquery without even doing on exercise in the book and never did javascript before and I had no problem doing jquery. Of course if you got javascript experience it is a plus since sometimes you will be trying to find a jquery solution when javascript already has a method for what you want to do.
Edit 3
A)
The only problem is that it can be a
bit trickery to do ajax request using
jquery when using asp.net
webforms(asp.net mvc was designed with
frameworks like jquery in mind so it
is easier to do).
Are you implying that perhaps jquery
could be too much of a hassle when
used together with webforms and thus I
should think of using Asp.Net Ajax
instead?
No I am not implying that it is too much hassle for webforms was just stating the fact that it will be a bit more tricky in certain situations then ms ajax and jquery with say asp.net mvc.
asp.net webforms was not really made for a framework like jquery and has trouble dealing with it because of it's page life cycle gets in the way. MS ajax might have it's own set of challenges though too(like everything usually does). Jquery was made in mind of to try and work across all browsers since in javascript many times you would write something that worked in IE but did not work in any other browser and I am not sure if MS ajax client side version thought about this.
B) Little I read on ajax is that it
also needs to call web services or
some other technology that provides
similar functionality to web services.
If true, which technology do you use (
WCF or Asp.Net web services or … )?
Yes this is true. This was the whole point many people including me where trying to make to prove that guy was wrong that asp.net was dying because of ajax, since you need something in the back end to make a call too.
However you can choose whatever you want. You can make a separate web service( can be a asp.net web service), you can have like static web service methods in your page load ( I never done this way) and the way I use to do it is by making a generic ajax handler.
You can't however just make a regular method in your page_load and try to call it as it has to go through the entire page life cycle.
http://encosia.com/2008/05/29/using-jquery-to-directly-call-aspnet-ajax-page-methods/
http://weblogs.asp.net/craigshoemaker/archive/2008/11/07/using-jquery-to-call-asp-net-ajax-page-methods-by-example.aspx
http://dotnetslackers.com/articles/ajax/using-jquery-with-asp-net.aspx
http://sites.google.com/site/spyderhoodcommunity/tech-stuff/usingjqueryinaspnetappswithhttphandlersashx
I have not read these tutorials but these tutorials should show you the 3 different ways you can do an ajax request to an asp.net webservice, asp.net code behind page and asp.net generic handler.
Choose what ever one you think is best. I don't know if one way is better then another and there probably are more ways to do it.
C) Is Ajax a subsection of jquery?
Thus, to understand Ajax, will I need
to purchase only a book on jquery or
will I also need to read a book with
Ajax in its title
Ajax is just part of jquery and probably won't take you long to learn. If you buy a book about jquery there will probably be like 1 chapter on it. The only down side is all the jquery books I know of are all in php.
So if your just buying it to learn the ajax part probably not worth it since they will show an entire example of how to do it with php that might be slightly different then if you did it with asp.net( mostly just setting up the server side to accept the jquery calls- see the links that I posted above).
If you want to learn jquery selectors and stuff then it does matter if the one chapter is in php since it's all client side stuff expect for the ajax part( what is client side and server side).
It's not hard to really do the ajax stuff it just knowing what path you need to choose and more how to accept stuff on the server side and return stuff from the server side.
$.post("test.php", { name: "John", time: "2pm" },
function(data){
alert("Data Loaded: " + data);
});
The above is basically all you need to do on jquery side to send some ajax stuff. The first parameter is the path where this request should go. In this case its some php file called test. The next parameter is the the actual data sent as a json result and finally the last line is the function call back line. When the ajax post request is done that line gets called and does the actions. Data is the returned stuff you sent back from the server.
http://api.jquery.com/jQuery.post/
So I would just go through the tutorials I posted and play around with the jquery selectors. Once you done that you can decide if you want to go with jquery or not. The last thing I wanted to point out about why I like jquery is the fact that if you learn the MS ajax stuff your basically stuck with asp.net( what I have no problem with since I love .Net) but with jquery you can easily take your code or those skills of jquery and use it with php, ruby or whatever else and all the client side jquery selectors won't change by switching a different language. The only thing that will be different is the ajax stuff and even that won't be 100% different as the jquery ajax client side could will be the same.