Is there a way to determine if an <asp:UpdatePanel /> has performed an Ajax postback similar to how we can use...
if(!Page.IsPostBack) { ...snip }
... to determine if a postback from a button submit is taking place.
I'm trying to detect Ajax requests from jQuery, but it's picking up UpdatePanel requests as well which I want to exclude eg...
if (Request.IsAjaxRequest() && !Page.IsUpdatePanelPostback)
{
// Deal with jQuery Ajax
}
You can check whether the postback was asynchronous and whether it was issued by an update panel looking at these properties:
ScriptManager.GetCurrent(Page).IsInAsyncPostback
ScriptManager.GetCurrent(Page).AsyncPostbackSourceElementID
I don't know if this will work any better than your solution, but have you tried?:
if (ScriptManager.GetCurrent(Page).IsInAsyncPostBack)
{
Control ctrl = GetControlThatCausedPostBack(Page);
if (ctrl is UpdatePanel)
{
//handle updatepanel postback
}
}
private Control GetControlThatCausedPostBack(Page page)
{
//initialize a control and set it to null
Control ctrl = null;
//get the event target name and find the control
string ctrlName = Page.Request.Params.Get("__EVENTTARGET");
if (!String.IsNullOrEmpty(ctrlName))
ctrl = page.FindControl(ctrlName);
//return the control to the calling method
return ctrl;
}
Try out following:
var controlName = Page.Request.Params.Get("__EVENTTARGET");
if (!String.IsNullOrEmpty(controlName))
{
// Use FindControl(controlName) to see whether
// control is of UpdatePanel type
}
Helpful links:
ASP.NET: Recursive FindControl & Extension Methods
Related
I am using a jQuery editor and when the user hits the submit button i put the content into asp.net Panel control as html and then when i render this Panel the html i added is not
retrieved.
function MoveData() {
var sHTML = $('#summernote_1').code();
// dvFrontPageHtml is asp.net Panel
$('[id*=dvFrontPageHtml]').html(sHTML);
setTimeout(function () {
javascript: __doPostBack('ctl00$ctl00$ContentPlaceHolderBody$ContentPlaceHolderBody$lnkSave', '');
}, 10000);
return false;
}
System.Text.StringBuilder sb = new System.Text.StringBuilder();
System.IO.StringWriter stWriter = new System.IO.StringWriter(sb);
System.Web.UI.HtmlTextWriter htmlWriter = new System.Web.UI.HtmlTextWriter(stWriter);
dvFrontPageHtml.RenderControl(htmlWriter);
string Message = sb.ToString();
The message does not returning the html added.
I dont want to use jQuery ajax call as of now.
Any suggestions
without seeing all the relevant code its hard to pinpoint the problem.
but im pretty sure you are trying to find an ASP.net control by its serverside ID from clientside.
dvFrontPageHtml is the Controls ID by which asp.net identifies it, and unless you explicitly tell ASP.Net otherwise, it will generate a different ID for the control to be used by scripts at clientside
you need to retrieve the panel's clientside ID thats being generated for it by asp.net
you do it by a preprocessor directive <%=dvFrontPageHtml.ClientID%>:
$('[id*=<%=dvFrontPageHtml.ClientID%>]').html(sHTML);
alternatively, if you want the clientside ID to be same as the serverside ID, you can set the control's attribute ClientIDMode="Static".
UPDATE:
from your comment it seems the problem is elsewhere. what comes to mind, is that RenderControl() takes the control as it was when sent to the client in the Response. but the control is not being submitted to the server in next Request, so you will not be able to retrieve its altered html.
what you can do as a workaround, is hook into ASP.NET's build in postback mechanism, and submit the panel's html as a custom event argument:
for the example, lets assume this is our html:
<asp:Panel ID="dvFrontPageHtml" runat="server" ClientIDMode="Static">test</asp:Panel>
<asp:Button ID="BT_Test" runat="server" Text="Button"></asp:Button>
this will be our javascript:
$(function(){
// add custom event handler for the submit button
$("#<%=BT_Test.ClientID%>").click(function (ev) {
//prevent the default behavior and stop it from submitting the form
ev.preventDefault();
//alter the panels html as you require
var sHTML = $('#summernote_1').code();
$('[id*=dvFrontPageHtml]').html(sHTML);
//cause a postback manually, with target = BTCLICK and argument = panel's html
__doPostBack('BTCLICK', $('[id*=dvFrontPageHtml]').outerHTML());
});
});
and here we capture the postback on serverside:
//we monitor page load
protected void Page_Load(object sender, EventArgs e)
{
string Message;
//check if its a postback
if (IsPostBack)
{
//monitor for our custom target "BTCLICK"
if (Request.Form["__EVENTTARGET"].CompareTo("BTCLICK") == 0)
{
// retrieve the panels html from the event argument
Message = Request.Form["__EVENTARGUMENT"];
}
}
}
On a page I have:
<asp:TextBox runat="server" ID="EmailTextBox" AutoPostBack="true" OnTextChanged="EmailTextBox_Changed" />
<asp:Button runat="server" ID="SearchButton" OnClick="AddButton_Click" Text="add" />
In EmailTextBox_Changed, it counts up how many emails can be found, before running the search.
The problem is, when you type something in EmailTextBox, and click on the button, you have to click twice to get the actual results up. This is because the first click is doing the "AutoPostBack" part from the text box, and then you have to click again to make the actual click postback to happen.
Without removing the "AutoPostBack=true", how can I stop it needing two clicks in these circumstances?
I was looking for an answer to this issue as well. I ended up removing all autopostback=true and doing all the actions with JavaScript, same as you.
However, one of the things I experimented with before the JavaScript was something to maintain control focus after a postback. I noticed the hidden field I used to store the name of the control that had the last focus DID have the name of the search button (mine is a save button). So, while I'm still not sure how to get the 'search' function to fire 'automatically' like it should, which is basically to chain the postback events from both the textbox AND the button together one after another, I CAN know that the user clicked that save button before the postback happened (or tried to).
So, what you have on postback is your textbox event firing, and then the Page_Load method, or whatever page cycle method you want to use, where you can check to see what the last control to have focus was. With this, there are several ways you could implement a work around.
Off hand, you could add code in every event that fires from a control autopostback, like the textbox and the search button, to check the name of the focus control. If the control that had focus last is NOT the control's autopostback function we are running, we can set a page level bool called 'Run_Controls_Method' to TRUE, else, set it to false. This way we know we should run the control that had last focus postback method.
On page load, you could do something like:
if (Run_Controls_Method && hdfFocusControl.Value != "")
{
switch(hdfFocusControl.Value)
{
case "btnSearch":
btnSearch_OnClick(null, null);
break;
case etc.
}
}
The way I implement the hdfHasFocus is:
HTML:
<input id="hdfHasFocus" runat="server" type="hidden" />
HTML code behind:
protected void Page_PreRender(object sender,EventArgs e)
{
if (IsPostBack != true)
{
//Add the OnFocus event to all appropriate controls on the panel1 panel.
ControlManager.AddOnFocus(this.Controls,hdfHasFocus,true);
//other code...
}
ControlManager.SetFocus(this.Controls,hdfHasFocus.Value,true);
}
ControlManager.cs related code:
/// <summary>
/// Adds the onfocus event to the UI controls on the controls in the passed in control list.
/// </summary>
/// <param name="controls">The list of controls to apply this event.</param>
/// <param name="saveControl">The control whose .value will be set to the control.ID of the control which had focus before postback.</param>
/// <param name="Recurse">Should this method apply onfocus recursively to all child controls?</param>
public static void AddOnFocus(ControlCollection controls, Control saveControl, bool Recurse)
{
foreach (Control control in controls)
{
//To make the .Add a bit easier to see/read.
string action = "";
//Only apply this change to valid control types.
if ((control is Button) ||
(control is DropDownList) ||
(control is ListBox) ||
(control is TextBox) ||
(control is RadDateInput) ||
(control is RadDatePicker) ||
(control is RadNumericTextBox))
{
//This version ignores errors. This results in a 'worse case' scenario of having the hdfHasFocus field not getting a
// value but also avoids bothering the user with an error. So the user would call with a tweak request instead of
// and error complaint.
action = "try{document.getElementById(\"" + saveControl.ClientID + "\").value=\"" + control.ClientID + "\"} catch(e) {}";
//Now, add the 'onfocus' attribute and the built action string.
(control as WebControl).Attributes.Add("onfocus", action);
}
//The 'onfocus' event doesn't seem to work for checkbox...use below.
if (control is CheckBox)
{
//This version ignores errors. This results in a 'worse case' scenario of having the hdfHasFocus field not getting a
// value but also avoids bothering the user with an error. So the user would call with a tweak request instead of
// and error complaint.
action = "try{document.getElementById(\"" + saveControl.ClientID + "\").value=\"" + control.ClientID + "\"} catch(e) {}";
//In case there is already an attribute here for 'onclick' then we will simply try to add to it.
action = action + (control as WebControl).Attributes["onclick"];
//Now, add the event attribute and the built action string.
(control as WebControl).Attributes.Add("onclick", action);
}
//You don't seem to be able to easily work the calendar button wiht the keyboard, and it seems made for
// mouse interaction, so lets set the tab index to -1 to avoid focus with tab.
if (control is CalendarPopupButton)
{
(control as WebControl).Attributes.Add("tabindex", "-1");
}
//We also want to avoid user tab to the up and down spinner buttons on any RadNumericTextBox controls.
if (control is RadNumericTextBox)
{
(control as RadNumericTextBox).ButtonDownContainer.Attributes.Add("tabindex", "-1");
(control as RadNumericTextBox).ButtonUpContainer.Attributes.Add("tabindex", "-1");
}
//Recursively call this method if the control in question has children controls and we are told to recurse.
if ((Recurse) && (control.HasControls()))
{
AddOnFocus(control.Controls, saveControl, Recurse);
}
}
}
/// <summary>
/// Searches the ControlCollection passed in for a match on the ID name string passed in and sets focus on that control if it is found.
/// </summary>
/// <param name="controls">The collection of controls to search.</param>
/// <param name="FocusToID">The ID of the control to set focus on.</param>
/// <param name="recurse">Recursively search sub-controls in the passed in control collection?</param>
/// <returns>True means keep processing the control list. False means stop processing the control list.</returns>
public static bool SetFocus(ControlCollection controls, string FocusToID, bool recurse)
{
//Return if no control ID to work with.
if (string.IsNullOrEmpty(FocusToID) == true)
{ return false; }
//If we get here and don't have controls, return and continue the other controls if applicable.
if (controls.Count <= 0)
{ return true; }
foreach (Control control in controls)
{
//If this is the control we need AND it is Enabled, set focus on it.
if (((control is GridTableRow) != true) && //GridTableRow.ClientID throws an error. We don't set focus on a 'Row' anyway.
(control.ClientID == FocusToID) &&
((control as WebControl).Enabled))
{
control.Focus();
//return to caller. If we were recursing then we can stop now.
return false;
}
else
{
//Otherwise, see if this control has children controls to process, if we are told to recurse.
if ((recurse) && (control.HasControls()))
{
bool _continue = SetFocus(control.Controls, FocusToID, recurse);
//If the recursive call sends back false, that means stop.
if (_continue != true)
{ return _continue; }
}
}
}
//We are done processing all the controls in the list we were given...
// If we get here, then return True to the caller. If this was a recursive call, then
// the SetFocus in the call stack above will be told to continue looking since we
// didn't find the control in question in the list we were given.
return true;
}
In fact, you don't have to click on the button to make the first event happen.
Just 'leave' the textbox, i.e. with 'tabbing' out of it to make the AutoPostBack happen.
If you want to do both in a single postback just remove the Button and do the things you do in AddButton_Click also in the Textbox_Change event.
Making it a client side check was the solution to this...there doesn't seem to be a way to prevent it otherwise
Write below code in Page_Load event to prevent twice click
BtnSaveAndPrint.Attributes.Add("onclick", "return confirm('Are you sure you Want to Save & Print?');")
You could avoid this by not doing it server side and using Javascript. You also didn't post your page load event. Are you checking if it post back or not ?
Another way you could do this is the event that happens on the click of the button can be called from the TextChanged event and get rid of the button all together.
I had the same problem, I decided to move the click event code to the page load event and execute it in case of postback. And not to use a click event at all.
protected void Page_Load(object sender, System.EventArgs e)
{
if (IsPostBack)
{
// put code here
}
}
instead of :
public void ButtonClick(object sender, EventArgs e)
{
//...
}
I have created a custom server side WebControl. This control calls an initialization script that uses jQuery to hookup the events with calls to bind when the page is loaded.
This control is now being used inside an UpdatePanel and obviously the client side events no longer exist after the UpdatePanel does it's thing. So, I need to re-run my initialization script if the control has been re-rendered as part of a partial page refresh and I don't see a good way of doing this.
I am aware of the ScriptManager.IsInAsyncPostBack and UpdatePanel.IsInPartialRendering, but they don't seem to provide what I need. It seems to implement this correctly that I will have to check if ScriptManager.IsInAsyncPostBack==true, then search up the control tree for an UpdatePanel that has IsInPartialRendering==true. If I find such an UpdatePanel then I re-run my initialization script.
Sounds horrible. Am I missing something simple? I can't be the only one who lives this way.
Thanks for reading!
Have you tried using the method described in the SO post below?
jQuery $(document).ready and UpdatePanels?
This is what I do when I use jQuery in update panels and it always works for me.
Have to do what I was afraid of... also, Update.IsInPartialRendering does not work, so you have to use reflection to figure out if the updatePanel is getting updated. So, if IsControlBeingRendered is true, then run your scripts.
public static bool IsControlBeingRendered(ScriptManager scriptManager, Control control)
{
if (scriptManager.SupportsPartialRendering && scriptManager.IsInAsyncPostBack)
{
UpdatePanel updatePanel = ControlHelper.FindParentByType<UpdatePanel>(control);
while (updatePanel != null)
{
if (IsBeingUpdated(updatePanel))
{
return true;
}
else
{
updatePanel = ControlHelper.FindParentByType<UpdatePanel>(updatePanel);
}
}
return false;
}
return true;
}
public static bool IsBeingUpdated(UpdatePanel updatePanel)
{
// unfortunately, updatePanel.IsInPartialRendering does not work. So, we must use reflection
// to check the protected property that actually does work..
if (updatePanel == null)
return false;
Type type = updatePanel.GetType();
BindingFlags bindingFlags = BindingFlags.NonPublic | BindingFlags.Instance | BindingFlags.GetProperty;
return (bool)type.InvokeMember("RequiresUpdate", bindingFlags, null, updatePanel, null);
}
I am creating a custom .NET AJAX Server Control, and need to get access to the JavaScript object functionality associated with that control. I can do this by finding the control in the ScriptManager using the $find method. However, I need to determine when I can call $find. If I do this on the "onload" event of the body of my HTML page, it can't find the control. Thus I end up having to locate the control with each event I wire up and my code ends up looking like this:
function button1_click() {
var control = $find("<%=Control.ClientID%>");
control.DoSomething();
}
function button2_click() {
var control = $find("<%=Control.ClientID%>");
control.DoSomethingElse();
}
I would rather store that control once, and use it throughout the rest of my event calls. Thus I'm hoping the code would eventually look something like this:
var _control = null;
function load() {
_control = $find("<%=Control.ClientID%>");
}
function button1_click() {
_control.DoSomething();
}
function button2_click() {
_control.DoSomethingElse();
}
Let me know if this doesn't make sense. I am new at creating these custom controls, so I'm not quite sure of the terminology yet. Thanks for your help!
The "load" DOM event occurs before the ASP.NET Ajax client-side framework is initialized. Client-side controls are initialized by handling the init event of the Sys.Application object. That's why an ASP.NET Ajax control's initialization script is output like:
Sys.Application.add_init(function() {
$create( ... )
});
You can use the load event of the Sys.Application object or its shortcut- the pageLoad method. It occurs after the init event and all ASP.NET Ajax controls will be initialized then. Here is some sample code:
var _control = null;
function pageLoad() {
_control = $find("<%= Control1.ClientID %>");
}
When the page class property IsValid is read only, how can I set it using my own validation method?
So far all I've been able to do is set this property by calling Page.Validate().
How can I write my own functionality that will change the IsValid property just like Page.Validate()?
You don't set IsValid directly instead you call Validate() method of the Page object. If you have your custom validation methods then you need to use CustomValidator object and set that function in its server side validation property.
<asp:CustomValidator ID="YourValidator" runat="server" SetFocusOnError="true"
ControlToValidate="YourControl"
ClientValidationFunction="YOUR_JAVASCRIPT_FUNCTION"
OnServerValidate="YOUR_SERVER_VALIDATION_FUNCTION" Text="*" />
I know this is old, but, I needed to do something similar, basically forcing the IsValid property to false (don't ask why). Here is what I did basically (what you see here is my proof of concept):
Added this to the .aspx page:
<asp:TextBox ID="txtDummy" runat="server" Visible="false" />
<asp:RangeValidator ID="rvDummy" ControlToValidate="txtDummy" runat="server" MinimumValue="1" MaximumValue="2" />
And then I added this to the code behind:
bool makeMyPageInvalid = true;
if (makeMyPageInvalid)
txtDummy.Text = "0";
Page.Validate();
if (Page.IsValid)
ScriptManager.RegisterStartupScript(Page, Page.GetType(), "test", "alert('valid');", true);
else
ScriptManager.RegisterStartupScript(Page, Page.GetType(), "test", "alert('not valid');", true);
You can see that this only allows you to force the page validation to an invalid state. You can use any validator or reason to set this. Hope this helps someone!
The IsValid property is read-only because it is intended for use with server and client-side validators like the RequiredFieldValidator and RegularExpressionValidator. It's read-only because you can't force a page to be valid programmatically. "Valid" in this context means all the validators on the page evaluate to true.
If you feel like using some JavaScript you can do it in the client-side by modifying the variable Page_IsValid like this:
function pageLoad() {
Page_IsValid = false;
}
I use this just in case someone clicks the submit button w/o entering data. Then I can display an alert like this:
function valid() {
if (!Page_IsValid) {
alert("Some Questions Remain Unanswered and are Marked with a Red Asterisc. ( * )");
}
(at the beginning I thought 'who would submit a form w/o data' but sooner rather than later I realized it happens)
This is a really old question, but it came up in a search so I thought I'd add my answer to it. First, create an extension method in one of your helper classes.
public static IEnumerable<T> GetAllControlsOfType<T>(this Control parent) where T : Control
{
var result = new List<T>();
foreach (Control control in parent.Controls)
{
if (control is T)
{
result.Add((T)control);
}
if (control.HasControls())
{
result.AddRange(control.GetAllControlsOfType<T>());
}
}
return result;
}
Now in your code behind file, loop over every validator on the page that is not validating.
foreach (var validator in Page.GetAllControlsOfType<BaseValidator>().Where(w => !w.IsValid))
{
validator.IsValid = true;
}