(Note: Just to clarify the problem is not specifically related to C1WebDateEdit. It could be with any custom control which require JavaScript to render actual control)
I have many C1WebDateEdit controls in my page. On a button click based on some condition I am displaying JavaScript alert message ScriptManager.RegisterStartupScript. These controls are inside UpdatePanel. The issue I am facing with it is, when these C1WebDateEdit has not value and page displays alert message, it displays "01/01/0001" behind the alert box and on closing alert it shows empty textboxes.
The reason is, C1WebDateEdit creates actual control using JavaScript. and page renders alert message JavaScript before C1WebDateEdit controls' JavaScript.
For example:
HTML markup
alert JavaScript
C1WebDateEdit JavaScript
Logical solution is get alert JavaScript after C1WebDateEdit JavaScript because it will allow C1WebDateEdit to load fully before alert box.
I found no inbuilt way in asp.net to change sequence, so I tries solution given here but It didn't work for me.
One possible solution I am thinking that I create Custom or WebUserControl and place at it last at the page in the UpdatePanel and PreRender event I call ScriptManager.RegisterStartupScript to register alert message. Logically I think it will work but trying to find that any one implemented any other solution for it?.
Other possible solution is use "pageLoaded" event of PageRequestManager. I created below function for temporary fix:
function delayedAlertBox(strMsg)
{
var fnc = function (a, b)
{
//remove reference so on next call it do not show previous alerts.
Sys.WebForms.PageRequestManager.getInstance().remove_pageLoaded(fnc);
alert(strMsg);
}
//add function reference to call on Ajax pageloaded event
Sys.WebForms.PageRequestManager.getInstance().add_pageLoaded(fnc);
}
and calling in asp.net like simple function as given below:
ScriptManager.RegisterStartupScript(Page, Page.GetType(), "dd", "delayedAlertBox('Hi, how are you?')", True)
But still looking for any other good alternative. If I found other, I will post it.
Related
I have a custom control (ascx) which implements the IPostBackEventHandler interface for intercepting custom events triggered by custom rendered HTML links.
In this control I use an update panel and inside the update panel I use a literal control in which I render custom HTML links.
When I render the HTML links inside the literal control I use a StringBuilder with the following code:
sb.AppendFormat ("Text",
this.Page.ClientScript.GetPostBackClientHyperlink(this, custom_string_param));
Hyperlinks are rendered fine, and when clicking on them an asynchronous postback is triggered and a partial update is fired (since all links are rendered inside the Update panel).
The problem is that I need to do some custom Javascript before firing the __doPostBack which is rendered with the above code. So here is a simplified version of the changed code:
sb.AppendFormat ("Text",
custom_string_param);
Also in the ascx markup I use the following code (inside or outside the Update panel):
<script language="javascript" type="text/javascript">
function JSFunc(param) {
// custom js code here ....
__doPostBack('<%=this.ClientID%>', param);
}
</script>
The problem here is that when a link is clicked it performs a full postback and not a partial one. I also tested more simple versions of the above code and it seems that if you remove the __doPostBack from the href or the onclick events from the link ( tag) and move it to a custom js function which in turns you supply to the link, a full postback is triggered.
Note that there is no error on the page and in both cases the code work correctly. The page is rendering correctly depending on the parameters returned from the __doPostBack, but in the second case a full instead of partial postback is firing.
Any ideas?
Thanks in advance,
George
I think you can't call __doPostBack with the ClientID. It actually uses UniqueIDWithDollars, but generally with ASP.NET Web Forms I say: you don't want to know.
Since calling this method is all about abstracting away the details of how post back works, you would be better off asking the framework for the code. Luckily, there's a special method just for that, which will take care of the details. In your code it would look like something like this:
<script language="javascript" type="text/javascript">
function JSFunc(param) {
// custom js code here ....
<%= Page.ClientScript.GetPostBackEventReference(this, custom_string_param) %>
}
</script>
This let's the client script manager create the piece of JavaScript code, using a reference to your user control (this) and any custom event argument (custom_string_param).
There's one caveat though. When calling it this way, it will add javascript: to the beginning of the string.
To override this behaviour, you need to use an overload of GetPostBackEventReference that accepts an instance of PostBackOptions as its first argument, the instance having its RequiresJavaScriptProtocol property set to false.
PostBackOptions options = new PostBackOptions(this, custom_string_param)
options.RequiresJavaScriptProtocol = false;
Page.ClientScript.GetPostBackEventReference(options)
I know my issue is very common and similar types has been asked many times over here, but my problem is somewhat different. I am working on ASP.Net 4.0 web application where on my required page i have ajax toolkit 4 calendar control, toolkitscript manager and few asp controls. Now from that pop up i am doing a save operation on button click. What i want is to close popup window after successful save. Problem is not in saving but after saving , automatically closing the popup screen. I have tried the following ways:
RegisterStartUpScriptBlock(this.GetType,"closeForm","return window.close();") and all other required params
ClientScript.RegisterStartUpScript()--- alongwith params and with both return window.close(); and window.close() also with self.close();
Also i have under the title tag...
I think i have tried all the ways , i can. I feel i am lost. Please help me out....
if your using a script manager on the page...
first create a function to close the calendar in js in your html...
function closeCalendar(){
....
}
then on the codebehind use this to call that js function
string script = string.Format(#"closeCalendar()");
ScriptManager.RegisterClientScriptBlock(this, typeof(Page), UniqueID, script, true);
If the popup you mean is the AJAX Toolkit Modal Popup, you can just call popup.Hide(); in codebehind.
If it is a browser window, did you try to remove the return part from your code?
Note that windows.close() will not work unless the popup is opened via window.open();
Also, did you try to just put the script tag inside PlaceHolder control that is hidden (server-side Visible=false) by default and only shown when you need?
I'm using Javascript to create a DIV element and open up a new page by using onclientclick. This works great. Now, I need to write to it from the server side and this element must be created before it is posted back.
How do I get the javascript to execute before the postback?
Currently, I have to press the button twice because the element doesn't exist to write too on the first click.
To be clear, I need this to execute before the "OnClick" of the button.
Update: It looks like the Javascript function is called before the postback but the element is not updated until I run the second postback. Hmm
Update: Unfortunately it is a bit more complicated then this.
I'm creating a div tag in javascript to open a new window. Inside the div tag, I'm using a databinding syntax <%=Preview%> so that I can get access to this element on the server side. From the server side, I'm injecting the code.
I'm thinking this may be a chicken-egg problem but not sure.
UPDATE!
It is not the Javascript not running first. It is the databinding mechanism which is reading the blank variable before I'm able to set it.
Hmm
you don't have to rely on server controls to perform postbacks in asp.net. you can gain finer control of your app by posting from javascript whenever you are ready..
the framework auto generates a function called __doPostback(.....) and eventually calls it every time it needs to do a postback.
so. instead of using server control button, you can have a regular <button onclick="foo()" />
than once you're done performing all that you need, just call the __doPostback function.
asp.net gives you a nifty way to access that function with
Page.GetPostbackClientEvent (i believe, but there are couple methods that support this methodology)
http://msdn.microsoft.com/en-us/library/system.web.ui.page.getpostbackclientevent.aspx
enter code hereWould this work for you?
Javascript
function stuffYouWantToDo(){
//do your stuff
//then submit the .NET form
document.forms[0].submit();
}
.NET code
<asp:button ID="Button1" onClientClick="return false;stuffYouWantToDo();"/>
This should ensure that the stuff you want to do is done, then the form will be submitted. The return false prevents the form from being submitted when you first click the button and relies on the call in the stuffYouWantToDo function to submit the form.
If you want to use jquery you could do the following:
$(document).ready(function() {
var execScript = $(".myButton").attr("href").replace("javascript:", "");
$(".myButton").attr("href", "#").click(function() {
// Add before click logic here
eval(execScript);
});
});
Couldn't you simply add a custom validator somewhere in your form?
I have a bunch of text boxes and a save button to update something. When I click Save I have code that determines whether they are correctly filled in, in the code behind file.
If they are not correctly filled in, I want to display an error message in the form of an alert.
What is the best way to do this? Pressing the button obviously makes the page postback, so I thought about adding something to the URL like mypage.aspx?errormessage=blahblah but I don't know if this is the best way or even how to do it...
Any suggestions?
Modal alerts are bad, as are postbacks. Try to check as much as possible on the client-side without a round-trip to server. See jQuery Validation plugins for a less intrusive way of validation.
Could you use a CustomValidator to trigger client side script that shows a alert box?
You could use the ClientScript.RegisterStartupScript() method in the server side error handling code to write a javascript snippet which calls alert('message'), something like this
private void ShowErrorMessage(string message)
{
string script = "alert('" + message + "');";
ClientScript.RegisterStartupScript(typeof(MyPage), "errorScript", script, true);
}
But I would recommend you use a validator instead. If you implement your own custom validator, you can make it emit client-side script which can run before the submit, to avoid the postback altogether.
A good thing about validators is that their error messages can be displayed in a ValidatorSummary on the page, avoiding the ugly alert box.
First of all I won't recommend showing an modal alert box to the user.
You can call a javascript function from the server side code and in that function you can pop out the error.
Or you can issue an AJAX request and after the validation on server side you can send back a response to the client.
ASP.NET's various validation controls (with client-side validation enabled), coupled with proper error messages and/or summary message will be good enough for most scenarios.
For 'AJAX feel and behaviour', put the controls into an updatepanel will be easy to implement too.
Use ye olde Validators as much as poss, they render out some javascript to the client so yu can do alot of validation using these controls and only when they are all satisfied does it allow the page to submit.
They do fire on every submit so if you don't want every submit action to fire them you make the controls part of a validation group.
They can validate input using regular expressions, make sure a field has a value and there is a few more as well.
Then there is property to declare a 'message' and a control to show all the validator messages. All very swish and built right into the IDE.
Go check out the validator controls.
Try the following code in your button click event:
string strErr="Error!";//Put your error message here
ClientScript.RegisterStartupScript(GetType(), "scrptName", "javascript: alert('"+strErr+"'); ", true);
It will show an alert message.
Else put a label on your aspx page and set visible false in page_load event.
When error occurs in your button event set the label visibility 'true' and fill the label text with the error message.
I'm using jQuery and SimpleModal in an ASP.Net project to make some nice dialogs for a web app. Unfortunately, any buttons in a modal dialog can no longer execute their postbacks, which is not really acceptable.
There is one source I've found with a workaround, but for the life of me I can't get it to work, mostly because I am not fully understanding all of the necessary steps.
I also have a workaround, which is to replace the postbacks, but it's ugly and probably not the most reliable. I would really like to make the postbacks work again. Any ideas?
UPDATE: I should clarify, the postbacks are not working because the Javascript used to execute the post backs has broken in some way, so nothing happens at all when the button is clicked.
Both of you were on the right track. What I realized is that SimpleModal appends the dialog to the body, which is outside ASP.Net's <form>, which breaks the functionality, since it can't find the elements.
To fix it, I just modified the SimpleModal source to append eveything to 'form' instead of 'body'. When I create the dialog, I also use the persist: true option, to make sure the buttons stay through opening and closing.
Thanks everyone for the suggestions!
UPDATE: Version 1.3 adds an appendTo option in the configuration for specifying which element the modal dialog should be appended to. Here are the docs.
All standard ASP.NET postbacks work by calling a __doPostBack javascript method on the page. That function submits the form (ASP.NET only really likes one form per page) which includes some hidden input field in which all the viewstate and other goodness lives.
On the face of it I can't see anything in SimpalModal that would screw up your page's form or any of the standard hidden inputs, unless the contents of that modal happened to come from a HTTP GET to an ASP.NET page. That would result in two ASP.NET forms being rendered into one DOM and would would almost certainly screw up the __doPostBack function.
Have you considered using the ASP.NET AJAX ModalPopup control?
Web browsers will not POST any disabled or hidden form elements.
So what's happening is:
The user clicks on a button in your dialog.
The button calls SimpleModal's close() method, hiding the dialog and the button
The client POSTs the form (without the button's ID)
The ASP.NET framework can't figure out which button was clicked
Your server-side code doesn't get executed.
The solution is to do whatever you need to do on the client (closing the dialog in this case) and then call __doPostback() yourself.
For example (where "dlg" is the client-side SimpleModal dialog reference):
btn.OnClientClick = string.Format("{0}; dlg.close();",
ClientScript.GetPostBackEventReference(btn, null));
That should hide the dialog, submit the form, and call whatever server-side event you have for that button.
#Dan
All standard ASP.NET postbacks work by calling a __doPostBack javascript method on the page.
asp:Buttons do not call __doPostback() because HTML input controls already submit the form.
got caught out by this one - many thanks to tghw and all the other contributors on the appendto form instead of body fix. (resolved by attributes on the 1.3 version)
btw: If anyone needs to close the dialog programmatically from .net - you can use this type of syntax
private void CloseDialog()
{
string script = string.Format(#"closeDialog()");
ScriptManager.RegisterClientScriptBlock(this, typeof(Page), UniqueID, script, true);
}
where the javascript of closedialog is like this....
function closeDialog() {
$.modal.close();
}
I have found the following works without modifying simplemodal.js:
function modalShow(dialog) {
// if the user clicks "Save" in dialog
dialog.data.find('#ButtonSave').click(function(ev) {
ev.preventDefault();
//Perfom validation
// close the dialog
$.modal.close();
//Fire the click event of the hidden button to cause a postback
dialog.data.find('#ButtonSaveTask').click();
});
dialog.data.find("#ButtonCancel").click(function(ev) {
ev.preventDefault();
$.modal.close();
});
}
So instead of using the buttons in the dialog to cause the postback you prevent their submit and then find a hidden button in the form and call its click event.
FWIW, I've updated the blog post you pointed to with come clarification, reposted here - the reasoning & other details are in the blog post:
The solution (as of my last checkin before lunch):
Override the dialog's onClose event, and do the following:
Call the dialog's default Close function
Set the dialog div's innerHTML to a single
Hijack __doPostBack, pointing it to a new function, newDoPostBack
From some comments I’ve seen on the web, point 1 needs some clarification. Unfortunately, I’m no longer with the same employer, and don’t have access to the code I used, but I’ll do what I can. First off, you need to override the dialog’s onClose function by defining a new function, and pointing your dialog to it, like this:
$('#myJQselector').modal({onClose: mynewClose});
Call the dialog's default Close function. In the function you define, you should first call the default functionality (a best practice for just about anything you override usually):
Set the dialog div's innerHTML to a single – This is not a required step, so skip it if you don’t understand this.
Hijack __doPostBack, pointing it to a new function, newDoPostBack
function myNewClose (dialog)
{
dialog.close();
__doPostBack = newDoPostBack;
}
Write the newDoPostBack function:
function newDoPostBack(eventTarget, eventArgument)
{
var theForm = document.forms[0];
if (!theForm)
{
theForm = document.aspnetForm;
}
if (!theForm.onsubmit || (theForm.onsubmit() != false))
{
document.getElementById("__EVENTTARGET").value = eventTarget;
document.getElementById("__EVENTARGUMENT").value = eventArgument;
theForm.submit();
}
}
The new Jquery.simplemodal-1.3.js has an option called appendTo. So add an option called appendTo:'form' because the default is appendTo:'body' which doesn't work in asp.net.
Had the same problem, but {appendTo:'form'} caused the modal popup to be rendered completely wrong (as though I had a CSS issue).
Turns out the template I'm building on top of has includes that put other forms on the page. Once I set {appendTo:'#aspnetForm'} (the default Asp.net form ID), everything worked great (including the postback).
In addition to tghw's answer, this excellent blog post helped me: jQuery: Fix your postbacks in Modal forms -- specifically BtnMike's comment: "You also must not have CssClass=”simplemodal-close” set on your asp:button." Taking that off the class was the not-obvious-to-me solution.
-John
if you don want modify the SimpleModal source.
try this..
After you call the modal() method add this:
$("#simplemodal-overlay").appendTo('form');
$("#simplemodal-container").appendTo('form');
the SimpleModal plugin add two this to your markup.
'simplemodal-overlay' for the background
'simplemodal-container' containig the div that you whant as pop up modal.