Is it possible to call the inserted event of formview in asp.net? from jQuery for example:
$ ('#FormView1').Inserted (function () (/ / code ....
how do it???
Not really.
FormView is a server-side object with server-side events - they are written in C# (or other .net language), and run on your server.
jQuery is a JavaScript framework - it runs on people's browsers.
It is possible to expose the functionality to AJAX calls as long as you're only updating the database. If the ItemInserted event is changing the page in any way, you'll have to rewrite it in jQuery. You will also experience problems with the ViewState once you do post the page back, so you may want to disable it (or your data will appear outdated when you post back). Either way, it isn't a quick fix as you might expected. Sorry.
Related
I'm dipping my toes into web development. Based on various bits of advice, I'm going to start by getting a handle on html, css and javascript.
I'm interested in Ajax, I've had a look at the client side code and that looks straight forward enough, I'm slightly confused about what I do on the server side.
I'm using IIS and ASP.NET. I've had a google but I can't find anything that is either simple or current. There's a lot of talk about the Ajax toolkit, which I believe are controls which use Ajax (and may be retired??) Everything else seems to be based on old versions which I don't trust.
So, in really simple terms, what do I have to do in IIS to respond to an AJAX call?
Quick aside, I believe we can use JSON for object serialisation?? I assume I don't need to in the interests of getting a simple sample running?
So I have an Ajax call which will have one parameter, and I want to return "something" based on the parameter. What is the simplest code to achieve that with IIS and ASP.NET?
Thanks
An AJAX call is basically just a regular call to your website. The only difference is how the browser handles it - AJAX calls are done in the background with Javascript (the J in AJAX) and then does something with the data. You could take the URL that you're doing an AJAX call with and put it in your address bar and it'll return the exact same data. So, basically, what you do on the server side is exactly what you would do as if it were a form being submitted, for example.
As far as object serialization, yes, JSON can do that.
First of all, doing ajax has nothing to do with IIS; it has to do with ASP.NET.
There are essentially 2 ways to do AJAX in .net
1) Heavy use of the framework. You can put your asp controls (such as literals, gridviews, listbox...) in a control called an updatepanel. For this to work, you need to add a script manager to the aspx page. Then, when the user raises an event (for example, paging and sorting of a table), the request is handled by the framework and only the part of the page that's in the updatepanel is refreshed. The other way to raise events is by using the __doPostback function that comes with the asp.net framework. The downside of this method is that a lot of data needs to go back and forth between the user and the server so it can be slow. The upside is that you don't have to worry about generating the HTML since the asp controls handle it for you.
2) Heavy use of Json. With this method, you can use jQuery to call a page method or a web service. You send a json object to the server and you get a json object back. With jQuery, this is really easy. The downside of this method is that you're getting just the json data back: no formatted HTML. So, if you're looking to have a table updated, this method would be tedious because you'd have to recreate the entire HTML. However, the upside of the method is that it's very fast because only the raw data is transmitted. If you implement a web service, you don't even need to create an entire page.
What do you need to get from the server?
If you want to return "something" from the server that's "simple" (just data), I'd recommend a web service with jquery to trigger the call. If the return data is "complex" (html code for controls) then I'd recommend using MS ajax with the update panel.
Don't use the AJAX Control Toolkit, ASP.NET AJAX library, updatepanels or the scriptmanager control. Microsoft have pretty much ditched the lot in favour of jQuery and its Plugins (sensibly).
Here are just some of the ways you can use AJAX with jQuery in ASP.NET: Many ways to communicate with your database using jQuery AJAX and ASP.NET
We have a method on an asp.net page that is called on a button click. The problem is that the method take a long time to process. I've been asked to have the page call the method (or call the postback) and then display the jquery.ui dialog which will let the user know that this process could take a long time. I'm looking at serializing the asp.net form and doing a $.post() but to be honest I'm completely stuck on whether this will even work and how I can prevent the actual postback from happening and just displaying the dialog. Has anyone had any experience with doing this that can give me some pointers?
I found this http://dotnet.dzone.com/news/eliminating-postbacks-setting- but I'm not sure if it's a bit OTT. The article is a little long winded.
Hope someone can help.
That would be easier if you can use an UpdatePanel (which basically boils down to ASP.NET's way of doing what you're considering with the $.post(), but automatically gets the ASP.NET specific stuff right).
Then, you can do something simple like this: http://encosia.com/2008/10/04/using-jquery-to-enhance-aspnet-ajax-progress-indication/
You can send a post request through javascript (AJAX) without using asp.net's ajax framework. So in other words do it manually. Ajax would be perfect in this case, because you are trying to show loading indicators on the front-end while you are waiting for a response from the server.
To do this, take the logic out of your button_click method and put it in a separate page (text.aspx see below). Then you can call that page like this (using JQuery):
$('#ProgressIndicator').show();
$.post("test.aspx", function(data){
alert("Data Loaded: " + data);
$('#ProgressIndicator').hide();
});
If you can't use JQuery in your project, see: AJAX
I currently have a simple form that when you click the "save" button will persist it to the database.
I would like to use JQuery to do the callback for me and popup a "Save completed" div window/div of some sort.
My only problem is how do I call the btnSave_Click() event from JQuery?
If I use PageMethods the method would have to be static and therefore lose access to my textboxes and other page controls?
Thanks,
Goosey
Are you explicitly trying to avoid passing the values of the input controls? because that would be much easier.
Using a lightweight jQuery call to do the post but then expecting a full control hierarchy in the code behind to pull data out? What's the intent here? If you require that, it would probably be easier just to submit the page, and register javascript to run to pop the success message up on load.
Personally, I think the page method route and $.ajax or $.post is a much cleaner, separate way to solve the issue. That way you can just show the popup as part of the success callback.
You can use onClientClick
Have a look at the jQuery Form Plugin, it can change existing forms into Ajax forms.
You need to set __EVENTTARGET to the id of the control that you want to simulate causing the postback if you want to use the same handler. I seem to recall having to replace the underscores with dollar signs as well, but I could be wrong on that. The hidden inputs, __EVENTTARGET and __EVENTARGUMENT, are used by the framework to identify which control caused the postback. There's a nice discussion of the server side issues in this blog post, though it doesn't talk about AJAX. Google for __EVENTTARGET and postback for more info.
Ok, so the problem is as follows: I'm using jQuery's AJAX in order to make behind the scene calls within the page (on events such as voting an item) and changing the content in the appropriate element. The problem occurs when I mix AJAX with ASP.net's AJAX, more precisely when I try to do a postback AFTER I've used jQuery on the page to perform an action. The page's viewstate is changed and validation fails (which would seem somewhat normal as a matter of fact).
My question is: can I disable the validation somehow so that I can perform postbacks combined with the chaged page viewstate? So far searching on how to disable it yielded no results.
A more practical example is on a comments page where I allow voting the comments and posting new comments as well. So should a user vote a comment and THEN post his own, the page's contents is changed, and thus validation fails. Also, I've tried placing the comment form within an update panel as to prevent the entire page from posting, but it still fails.
Of course I could use an alternate route and have a different page for handling the event and just call that via jQuery's AJAX, but I was wondering if I could do this by combining ASP.net and jQuery.
Thanks in advance.
If you want to disable viewstate verification, you can set it at the page or config level by using Page.EnableViewStateMac = false.
http://msdn.microsoft.com/en-us/library/system.web.ui.page.enableviewstatemac.aspx
It's not necessarily a good idea though because the validation functionality is there to protect from viewstate tampering, which you'll be turning off...
If you're running into issues with invalid viewstate because of jQuery ajax calls, one option is to consider using the Ajax controls, such as the UpdatePanel. You can wrap certain controls and mark the UpdatePanel as conditional to ensure a small round trip. This will not interfere with viewstate and allow you to continue to use viewstate validation and ajax at the same time.
There may be ways to use jQuery ajax calls and not interfere with viewstate validation. Others may be able to highlight this approach.
I can't seem to get the jQuery.ajax() function posting back any of my asp.net generated form controls.
I've put a break point on the server side and there aren't any values.
Is there a way around this or do I have to build up a list of what I want sent back?
Another question slightly off topic, but it seems that although jQuery is a great JS library, it doesn't seem to integrate too well with .net.
Has anyone given up with jQuery to perform server side interaction and just gone with ms ajax implementation?
The reason for this is because asp.net webforms doesn't use a normal post (ie. with an input/submit button). if you take a look at how those are posted, there is some javascript handler that ends up calling a built-in function that asp.net writes out to the page called __doPostBack.
Check out this other stackoverflow answer that might give you additional clues:
Jquery asp.net Button Click Event via ajax
To your second question, once you work out a few of the kinks, jQuery is a fantastic lib that has a ton of support and reference material both on the web and in books. Keep at it and you won't regret it :-)