Velocity Reviews - Computer Hardware Reviews

Velocity Reviews > Newsgroups > Programming > ASP .Net > ASP .Net Web Services > Accessing a .NET Webservice via JavaScript

Reply
Thread Tools

Accessing a .NET Webservice via JavaScript

 
 
AlBruAn
Guest
Posts: n/a
 
      08-14-2007
I have a need for a Web Service to retrieve values from a SQL Server database
to populate a dropdown list. That, without any further explanation, sounds
quite simple. The problem is the dropdown list is in FCKeditor, an
open-source WYSIWYG HTML editor written entirely in JavaScript. When the
editor is displayed, I need to query the database based on values selected
from two standard ASP dropdown lists on the page and return the results of
that query to populate the dropdown list in FCKeditor.

Should I write a section of JavaScript in my page to retrieve the selected
indexes of the two ASP dropdown lists once a selection is made and have the
JavaScript function call the Web Service? If so, how do I write the Web
Service to accept the two pieces of information? And how, for that matter,
do I send the message to the Web Service from JavaScript? This thing has me
really confused.
 
Reply With Quote
 
 
 
 
Laurent Bugnion, MVP
Guest
Posts: n/a
 
      08-17-2007
Hi,

AlBruAn wrote:
> I have a need for a Web Service to retrieve values from a SQL Server database
> to populate a dropdown list. That, without any further explanation, sounds
> quite simple. The problem is the dropdown list is in FCKeditor, an
> open-source WYSIWYG HTML editor written entirely in JavaScript. When the
> editor is displayed, I need to query the database based on values selected
> from two standard ASP dropdown lists on the page and return the results of
> that query to populate the dropdown list in FCKeditor.
>
> Should I write a section of JavaScript in my page to retrieve the selected
> indexes of the two ASP dropdown lists once a selection is made and have the
> JavaScript function call the Web Service?


Yes.

> If so, how do I write the Web
> Service to accept the two pieces of information?


First, you got to decide if you really want to use a Web Service
(meaning, SOAP) for this quite simple method. Probably it's not the best
idea. SOAP is very bloated, and parsing a SOAP message using pure
JavaScript is quite complex.

The best idea is probably to rather use an ASHX custom handler on the
server, and have it send back some XML data to the calling client. This
is rather simple, see here:
http://www.galasoft.ch/mydotnet/arti...006100601.aspx


> And how, for that matter,
> do I send the message to the Web Service from JavaScript? This thing has me
> really confused.


Unfortunately I never managed to write the article's part two, which is
how to use JavaScript to call the ASHX page you created above.
Thankfully, it's not very complicated. You do this using the
XmlHttpRequest object, which is available in IE, Firefox and other browsers.

To send a request using XmlHttpRequest, you should check the various
tutorials available online.
I recommend:
http://www.ajaxtoolbox.com/

HTH,
Laurent
--
Laurent Bugnion [MVP ASP.NET]
Software engineering, Blog: http://www.galasoft.ch
PhotoAlbum: http://www.galasoft.ch/pictures
Support children in Calcutta: http://www.calcutta-espoir.ch
 
Reply With Quote
 
 
 
Reply

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Example of how to call a .net webservice via javascript on a timed delay Josh Harris ASP .Net 1 07-30-2008 08:41 AM
Certificate issue with WCF client accessing webservice via broker Ryan ASP .Net Web Services 0 10-09-2007 05:21 PM
Timeout accessing .Net Webservice via POST or GET Achim Domma Ruby 2 05-24-2007 09:44 AM
WebException when accessing webservice via proxy Greg ASP .Net Web Services 4 03-17-2006 10:57 AM
Accessing List Items that were added to a list box via JavaScript Scott324 ASP .Net 3 10-27-2005 09:17 PM



Advertisments