We Keep Coding

Checking Div Visibility in ASP.NET using Javascript

How do you check if a div's visibility is hidden using JavaScript and ASP.Net?
If you look below, I am using an "if statement" to return an Alert("hi") if the div is not visible. Yet, the code is not working.
Any help is appreciated, thank you. Language is C#/JavaScript
<script>
function emptyRunReportConfirmation() {
var divDateFiltersID = document.getElementById('<%=divDateFilters.ClientID%>');
if (divDateFiltersID.style.visibility == "hidden") {
alert("hi");
}
}
</script>
<!-- this is a button to call the function -->
<asp:Button ID="buttCustomerFilt" runat="server" class="btn btn-primary" ClientIDMode="Static" Text="Run Report" OnClientClick="if ( ! emptyRunReportConfirmation()) return false;" OnClick="buttCustomerFilt_Click" /></div>
<!-- this is the div to check if visible -->
<div runat="server" id="divDateFilters" visible="false"></div>

Setting visible="false" on a runat="server" element will remove the element entirely from the page. The DIV element will not render at all. You could check your HTML to verify this.
It depends a bit on what you want to do, but in this case if you use visible="false" you can check if the variable is empty to see if the element exists.
if (!divDateFiltersID) {
alert("hi");
}

Calling button click from JavaScript asp.net doesn't work

I am trying to invoke a server side method through JavaScript by first displaying a confirm message and then trigger a button click on the page to call the function. However, the .click() method doesn't seem to work. Any ideas?
<script type="text/javascript">
function confirmDelete() {
var button = document.getElementById("hiddenButton");
if (confirm("Are you sure you would like to delete the row")) {
button.click();
}
}
</script>
and the button is defined like follows
<asp:Button ID="hiddenButton" runat="server" onclick="showHiddenMessage" Text="hidden" width="100px" />
Everything that I have found suggest that it should. including here:
http://www.comptechdoc.org/independent/web/cgi/javamanual/javabutton.html
and here:
Call ASP.NET function from JavaScript?

var button = document.getElementById('<% =hiddenButton.ClientID %>');
Id of server side controls is different on client side. modify code as above and try.
Modify confirmDelete() method as below:
function confirmDelete() {
if (confirm("Are you sure you would like to delete the row")) {
__doPostBack(( 'hiddenButton', '' );
}
}

Take a look at the ClientIDMode property of a Button. Setting this to Static will cause the button to render with the ID you entered in to your ASP.NET code. https://msdn.microsoft.com/en-us/library/system.web.ui.control.clientidmode.aspx
<asp:Button ID="hiddenButton" runat="server" ClientIDMode="Static" onclick="showHiddenMessage" Text="hidden" width="100px" />
If you look at the generated HTML, you should see the ID of this button as hiddenButton which should allow your Javascript to work.
By default ClientIDMode value will be Inherit, and will include the NamingContainer within the ID. This means the ID of the rendered HTML will be something like Panel1_hiddenButton and your Javascript won't find it with the current code.
For reference:
Static - The ClientID value is set to the value of the ID property. If the control is a naming container, the control is used as the top of the hierarchy of naming containers for any controls that it contains.
Inherit - The control inherits the ClientIDMode setting of its NamingContainer control.

But why don't you use your javascript function with your button? I think it is better:
<script type="text/javascript">
function confirmDelete() {
if (confirm("Are you sure you would like to delete the row?")) {
return true;
}
return false;
}
And your button:
<asp:Button ID="hiddenButton" runat="server" OnClientClick="return confirmDelete();" onclick="showHiddenMessage" Text="hidden" width="100px" />
In this case if user will click OK button, your showHiddenMessage function will occur. Otherwise nothing will be happen.

Unable to make ASP.NET control button fade out with JQuery

I have a simple enough problem: I have an ASP.NET control button and I want to make it fade out and then call some function (such as an alert) using JQuery. Here is what I have so far:
ASP Code for the Button:
<div id="begin">
<span id="startButtonSpan">
<asp:Button ID="startButton" class="startButton" runat="server" Text="Click Me!" OnClientClick="startButtonClick()"/>
</span>
</div>
JavaScript:
function startButtonClick()
{
$("#startButtonSpan > input").fadeOut(500, callAlert());
}
function callAlert()
{
alert("Made it here...");
}
When I click the button, the alert displays but the page does not even seem to try to perform the fadeOut. When I close the alert, the button is still there, staring at me.
Can anyone see any mistakes or does anyone have any suggestions on how I might be able to achieve the intended goal of fading out my button? Fadeout is really just my way of testing whether I can manipulate ASP controls using jQuery, so more than just the simple fadeOut, this is me trying to learn how to do that.
I tried a slightly more simple jQuery call using the code below, but it does not seem to work either:
ASP Portion:
<div id="begin">
<span id="startButtonSpan">
<asp:Button ID="startButton" class="startButton" runat="server" Text="Click Me!" OnClientClick="startButtonClick()"/>
</span>
</div>
<div id="jQueryTest" style="display:none;">
Block for testing jQuery.
<h1 id="testMessage">Child element for the ASP div.</h1>
</div>
Javascript Portion:
function startButtonClick()
{
$("#jQueryTest").css("display", "block");
$("#jQueryTest").show();
}
For this example, the text does display, but it immediately disappears again.
Any help or suggestions as to what I might be doing wrong would be greatly appreciated.

Use the class as a selector $('.startButton') instead of the ID since ASP.Net controls change their IDs dynamically when rendered by appending its Page & Control information.
$(".startButton").fadeOut(500, callAlert);
Or, if you're adamant about using the ID, here is another way to handling the selector,
$("#<%=startButton.ClientID %>")
Or, as Jacob suggested in his answer, you could ClientIDMode="Static", but this works only if your application is .Net 4.0 or above.
Also, use CssClass instead of class
<asp:Button ID="startButton" Csslass="startButton" runat="server" Text="Click Me!" />

The first example has 2 problems.
1. You should write
$("#startButton").fadeOut(500, callAlert);
and not
$("#startButton").fadeOut(500, callAlert());
2. For ASP.NET you must set ClientIDMode="Static" ortherwise asp.net will alter your id.
<asp:Button ID="startButton" ClientIDMode="Static" ... OnClientClick="startButtonClick()"/>

How about the fact that your code is fine (although other answers here should be considered) but your button is making a post back to the server and simply your browser does not have enough time to render the fade effect.
To test this, add a return false; to the OnClientClick property. This will of course cancel your action on the server but you will obtain the fade effect:
<asp: Button ... OnClientClick="startButtonClick();return false;"></asp:Button>
To work around this and still submit your request, you can try to use the ASP.NET __doPostBack method in JavaScript
ASP.NET:
<asp:Button ID="startButton" class="startButton" runat="server" Text="Click Me!" OnClientClick="startButtonClick(this);return false;"/>
JavaScript:
function startButtonClick(button)
{
$("#startButtonSpan > input").fadeOut(500, function(){__doPostBack(button.name, "")});
}
The __doPostBack method takes two arguments: the name of the control that is doing the postback and a postback argument that can be use to send more info on the server. In the case of the asp:Button, the name of the button should be sufficient to send the request without a problem.
Using this technique you will fade the button on the client and also trigger the action on the server. I cannot guarantee that this exact code will work (I don't have access to a dev environment right now) but you should get the idea.

If I could, I would like to provide another answer for those that use MasterPages and find that you can't always use $("#<%= SomeContentControl.ClientID %>") when working with Content controls.
What I do is set the MasterPage ID in my Init() like this:
protected void Page_Init( object sender, EventArgs e )
{
// this must be done in Page_Init or the controls
// will still use "ctl00_xxx", instead of "Mstr_xxx"
this.ID = "Mstr";
}
Then, you can do something like this with your jQuery:
var masterId = "Mstr",
$startButton = getContentControl("startButton"),
$message = $("#jQueryTest");
function getContentControl( ctrlId )
{
return $("#" + masterId + "_" + ctrlId);
}
function hideStartButton()
{
$startButton
.stop(true, true)
.fadeOut("slow", showMessage);
}
function showMessage()
{
$message
.stop(true, true)
.fadeIn("slow");
}
$startButton.on("click", hideStartButton);
Here is a jsFiddle that has the Mstr_ prefix already inserted as if ASP.NET rendered it.

When changing iframe src via javascript, the whole page refreshes

in my asp.net application I have a page That has two iframes. Above these frames are a few link buttons. When these buttons are hit, they should change the src of the two iframes. Listed below is the client side code and javascript I am using to do this. The issue is when any of these buttons are hit, instead of just changing the src of one of the iframes, the whole page refreshes. (i can tell this is refreshing because the link buttons are not available till you log in on the first page shown in the main frame, after you log in the buttons become visible via a call to the parent - window.parent.loginSuccess() ). If one of them is then clicked, it sends you back to the log in page in the iframe and the buttons are are no longer visible.) Here is the code, does anyone see why this is happening? Thank you for your help.
<body id="bodysty">
<div id="fstyle" class="daform">
<form id="form1" runat="server">
<div id="master">
<div id="topthing"> <asp:LinkButton ID="lbtnControlPanel" onclientclick="CPhit()" runat="server" style="display:none">Control Panel</asp:LinkButton> <asp:LinkButton ID="lbtnAddClient" runat="server" onclientclick="AddClientHit()" style="display:none">Add Client</asp:LinkButton> <asp:LinkButton ID="lbtnManageClients" runat="server" onclientclick="ManageClientsHit()" style="display:none">Manage Clients</asp:LinkButton> <asp:LinkButton ID="lbtnAdmin" runat="server" onclientclick="ManageClientsHit()" style="display:none">Admin Options</asp:LinkButton></div>
<div id="leftcontrol">
<iframe id="LeftIframe" runat="server" ></iframe>
</div>
<div id="mainbodyform">
<iframe id="ContentIframe" runat="server" src="Login.aspx" class="mainiframe" ></iframe>
</div>
</div>
</form>
</div>
</body>
</html>
<script language="javascript">
function CPhit() {
document.getElementById("ContentIframe").src = "LoginNotes.aspx";
}
function AddClientHit() {
document.getElementById("ContentIframe").src = "NewCustomer.aspx";
}
function loginSuccess() {
document.getElementById('lbtnControlPanel').style.display = 'inherit'
document.getElementById('lbtnAddClient').style.display = 'inherit'
document.getElementById('lbtnManageClients').style.display = 'inherit'
document.getElementById('lbtnAdmin').style.display = 'inherit'
}
</script>
There is no code in the codebehind that deals with this page, its simply for navigation. Any ideas? Thank you for your help.

You need to cancel the default click action of the item you are clicking on.
Simple way is to return false on the click event.
onclientclick="CPhit(); return false;"
better way is preventDefault()

It might be related to the behaviour of the button Try
event.stopPropagation() or window.event.cancelBubble = true
in your JS functions

ASP.NET on button click in user control set the value of a textbox in the main page using javascript

net/C# application, I have a user control containing a button.
I am loading the control in a PlaceHolder on the main page at runtime.
<asp:PlaceHolder ID="PlaceHolder1" runat="server">
</asp:PlaceHolder>
Code Behind:
MyControl CC = (MyControl)LoadControl("Controls/MyControl.ascx");
PlaceHolder1.Controls.Add(CC);
on the main page I have a text box and a link button. I want to do the following:
When the user clicks on the button in the user control, the textbox value is set to '5' and the link button click event is fired using javascript.
I tried the following but it did not work:
IN THE MAIN PAGE:
<asp:TextBox ID="PageBox" runat="server"></asp:TextBox>
<asp:LinkButton ID="LinkButtonPage" runat="server" onclick="LinkButtonPage_Click" Text="Submit"></asp:LinkButton>
IN THE USER CONTROL:
<script type="text/javascript">
function SetPage(a) {
var txtFld = document.getElementById("PageBox");
txtFld.value = a;
document.getElementById('LinkButtonPage').click();
return false;
}
</script>
<input type="button" id="Button1" onclick="SetPage('5');" value="Submit"/>
But when i click on the button nothig happens.
Thank you for any help

You are getting the ids of the controls wrong. You should be doing:
document.getElementById('<%=PageBox.ClientID%>');
And
document.getElementById('<%=LinkButtonPage.ClientID%>');
Also, you need to move your JavaScript function to the main page because that's the one that has the reference to both controls.

if you want to submit the page after changing the textbox value try this:
<script type="text/javascript">
function SetPage(a) {
var txtFld = document.getElementById("<%=PageBox.ClientID%>");
txtFld.value = a;
document.forms[0].submit(); // or document.forms['formname'].submit()
return false;
}
</script>

I fixed the problem by adding the function directly in the onclick event of the button
<input type="button" id="Button1" onclick="document.getElementById('PageBox').value='5';document.getElementById('LinkButtonPage').click();return false;" value="Submit"/>