I have an HTML table on my form. Column 1 contains a dropdown and a hidden span, Column 2 contains a hidden span. I need to show both spans and hide the drop down after a user makes a selection. I have done something similiar in other apps using code like this
var ddl_change = function() {
var ddl = this;
$("lbl1").text(ddl.options[ddl.selectedIndex].text).show();
$(ddl).hide();
}
if have 4 dropdowns (rows in the table). For code reuse I would like to use the same handler. I suppose I could write 4 seperate handlers, but that seems like a waste.
The html for a row looks like this
<tr>
<td>
<asp:DropDownList runat="server" ID="ddlbc1" />
<asp:Label runat="server" ID="lbl1" />
</td>
<td>
<asp:Label runat="server" ID="bd1" />
</td>
</tr>
I have the full client controls Id's if I need them. Anyways, is there a way within this single function to handle any row? I added client change event handlers to all the necessary drop downs and pointed them to this single function. I verified they are all correctly wired up. I want lbl1 textx to be the ddl selectedValue, and bd1, in the adjacent cell, to have ddl selectedText. Any help from the jQuery guru's would be appreciated. Thanks guys!
Cheers,
~ck in San Diego
$("td select").change(function(e){
$(this).hide().parent().parent().find("span").show();
});
Give it a whirl. You could also manage it by directly modifying the CSS, or changing the class.
You could target the entire table at once rather than a row using $("#table-id-name select") instead of the $("td select") (which will select all TD's in the entire page).
If you gave your lists/spans classes that would help to identify them, but it could be done otherwise.
$('table select').change( function() {
var $this = $(this);
$this.hide();
var lbl = $this.next('span');
var bd = $this.closest('td').next('td').find('span');
lbl.text( $this.val() ).show();
bd.text( $this.find('option:selected').text() ).show();
});
Related
I have a dynamically named DIV in a GridView which contains a user control with a dynamically assigned Parent_ID. The javascript is used to show or hide the DIV. I'll show you two examples of different rows without the ASP code.
Row 1 showing for Order # 123456:
<a href="<%#"javascript:collapseExpand('Order_Notes_Panel123456');" %>" >+</a>
<div id='Order_Notes_Panel123456' style="display:none;">
<uc:Comments_Control id="Comments_Control_ID" runat="server" Parent_ID='123456'/>
</div>
Row 2 showing for Order # 678901:
<a href="<%#"javascript:collapseExpand('Order_Notes_Panel678901');" %>" >+</a>
<div id='Order_Notes_Panel678901' style="display:none;">
<uc:Comments_Control id="Comments_Control_ID" runat="server" Parent_ID='678901'/>
</div>
The good news is that the user control binds and works perfectly. The javascript shows (sets the style to "display:block;") and hides (style set to "display:none;") the appropriate DIV each time the '+' is clicked.
Here is my problem: there is a 'Reply' link in the user control that, when clicked, does a post-back and puts the control into Edit mode. When I employ this user control on another page without a containing DIV, you won't notice a thing. However, when the 'Reply' does its post-back, the containing DIV reverts back to style="display:none;".
Can you provide a recommendation how to set the parent DIV's style to "display:block;" while a user is obviously working with it? I would imagine the appropriate code would go in the code behind of the user control when it goes into Edit mode.
Thanks,
Rob
Update: I recognize that there is no runat=server in my DIV. Since I'm trying to establish a dynamic ID for each, I get an error if I try to use the runat. That is probably the reason why I can't reach it from code behind...
I am very happy of myself... (see the YouTube video for this phrase, you'll be glad you did.)
In summary, this is what I added:
1. New Javascript function to add the name of the target DIV to a hidden field (The "collapseExpand" function is in the Site.Master. I couldn't put "load_div_to_hidden" in the Site.Master since "myhiddenField" isn't set up on every page
2. New hidden field to capture the name of the target DIV
3. New Javascript function to run on window.onload, check if we've got a post-back, and then display the value from the hidden field
4. Adding second Javascript call from the href in the link
Below are the new snippets of code:
<script type="text/javascript">
function load_div_to_hidden(obj) {
var hidden = document.getElementById('<%= myhiddenField.ClientID %>');
hidden.value = obj;
}
function windowOnLoad() {
var isPostBack = (('<%= IsPostBack %>').toLowerCase() == 'true') ? true : false;
if (isPostBack == true) {
var hid_field_value = document.getElementById('<%= myhiddenField.ClientID %>').value;
var right_div = document.getElementById(hid_field_value);
right_div.style.display = "block";
}
}
window.onload = windowOnLoad;
</script>
<input type="hidden" id="myhiddenField" runat="server" value="" />
<a href="<%#"javascript:collapseExpand('Order_Notes_Panel123456'); javascript:load_div_to_hidden('Order_Notes_Panel123456');" %>" >+</a>
<div id='Order_Notes_Panel123456' style="display:none;">
<uc:Comments_Control id="Comments_Control_ID" runat="server" Parent_ID='123456'/>
</div>
Works like a charm!
Is it possible to grab the cell data from Repeater items property such as
Dim test As String = myRepeater.Items(index).DataItem(2)
where myRepeater has x rows and 10 columns and was bound from the DataTable
Seems like it should be trivial, but looks like individual cells CAN NOT be accessed. Please shed some light on this.
Not directly -- remember, repeaters are very, very simple webcontrols and the repeater itself really has a limited idea of what is underneath it.
But you can easily get at items within. The best method is to use a control within the item to help you find stuff. EG, given this repeater "row":
<ItemTemplate>
<asp:Button runat="server" ID="theButton" text="Click Me!" OnClick="doIt" /> <asp:TextBox id="theTextBox" value="Whateeavs" />
</ItemTemplate>
You can use the button's click handler to find other items in the row:
protected void doIt(object s, EventArgs e) {
var c = (Control)s;
var tbRef = c.NamingContainer.FindControl("theTextBox");
var tb = (ITextControl)tbRef;
doSomethingWith(tb.Text);
}
Typically much cleaner than finding things in rows using absolute positioning -- you don't have to worry about indexes and such.
PS: it has been a long time since I laid down significant web forms code, no garuntees I got the class names, etc, exactly right.
Simply I am trying to pass the client Id of one textBox 'txtPersonId' for the client-click event so that I can traverse to that textBox control and pass its jQuery wrapper to the loadePerson() function.
This is how I decalre it in the aspx mark-up:
<asp:Button ID="btnSearch" runat="server" Text="ARA" OnClientClick="loadPerson(jQuery('#<%=txtPersonId.ClientID %>'))"/>
But when I render it, the
<%=txtPersonId.ClientID %>
place holder stays as it is and it is not replaced with the rendered control's client Id.
Any idea why this happens and how should I overcome that?
When I've had issues like this I've resorted to wrapping the entire expression in the brackets and building the result as a string. I assume that it's because the parser doesn't recognize the render block syntax embedded inside the string property.
<asp:Button ID="btnSearch" runat="server" Text="ARA"
OnClientClick='<%= "loadPerson(jQuery(\"#" + txtPersonId.ClientID + "\"))" %>' />
I've long since moved on to keeping my javascript completely separate from my mark up, so I may be a little fuzzy on the exact details. If you wanted to separate your javascript from your mark up you could either add the handler with an explicit or relative DOM reference in a script block. Using the "ends with" selector matching on the id removes the need to find the explicit id, though you could also do that -- the example below shows both styles.
<script type="text/javascript">
$(function() {
$('#' + '<%= btnSearch.ClientID %>').click( function() {
loadPerson( $('input[id$=txtPersonId]') );
});
});
</script>
I don't know what it does your LoadPerson,but if you want write a function for your click event in Jquery you can make something like:
'#'+ '<%=txtPersonId.ClientID %>' to address your txtbox ID you can do the samething for your button $('#' + '<%=btnSearch.ClientID%>').click(function(){//click event process});
Consider this scenario:
<asp:CheckBoxList> in a master page.
the goal is to have all checkboxes in this list to be checked on page load.
there are many checkbox lists on the page.
The markup:
<asp:CheckBoxList runat="server" ID="chkSubscriptionType"
DataSourceID="myDS"
CssClass="boxes" DataTextField="Name" DataValueField="Name" />
renders to:
<input id="ctl00_cphContent_chkSubscriptionType_0" type="checkbox" name="ctl00$cphContent$chkSubscriptionType$0" />
Question: how can you use jQuery to check all boxes in this asp:CheckBoxList on document.ready? I see samples everywhere, but naming convention used by the master page throws off the samples in other places.
Because of the naming container, the ID's will be auto-generated and messed up, as you mention. You can use an attribute filter to select all elements that contain the part that you do know, that is, "chkSubscriptionType". For example:
$("input[id*=chkSubscriptionType]").attr("checked", "checked");
The *= means "contains".
ASP.NET's naming conventions are slightly frustrating. You can side-step them by wrapping your element in a span, and giving it a class. You can then use that span.class to focus your selector:
$(function(){
// On dom-ready, all checkboxes in span.names will be checked
$("span.names :checkbox").attr("checked", "checked");
});
<span class="names">
<asp:CheckBoxList ... />
</span>
Regardless of asp/php/ruby, etc, you should be able to do something like:
$(document).ready(function(){
$("input[type=checkbox]").attr("checked", "checked");
});
i have a series of rows that are generated using an asp:repeater:
<asp:repeater ID="itemsRepeater"
OnItemDataBound="itemsRepeater_ItemDataBound"
runat="Server">
<itemtemplate>
<tr>
<td>
<asp:HyperLink ID="linkView" runat="server"
Text="<%# GetItemText((Item)Container.DataItem) %>"
NavigateUrl="<%# GetViewItemUrl((Item)Container.DataItem) %>" />
</td>
<td>
<asp:HyperLink ID="linkDelete" runat="server"
Text="Delete"
NavigateUrl="<%# GetDeleteUrl((ActionItem)Container.DataItem) %>" />
</td>
</tr>
</itemtemplate>
</asp:repeater>
The repeater creates an HTML table, with each row containing a link to an item and (what is essentially) a "Delete" link. The above simplified example code generates HTML similar to:
<TR>
<TD>
<A href="ViewItem.aspx?ItemGuid={19a149db-5675-4eee-835d-3d78372ca6f9}">
AllisonAngle_SoccerGirl001.jpg
</A>
</TD>
<TD>
Delete
</TD>
</TR>
Now that all works, but i want to convert the "Delete" to client side. i want to be able click the link and it will, on the client javascript:
prompt an alert "Are you sure..."
have javascript issue server-hit to actually delete the item they want
remove the item from the client DOM tree
So there are four problems to be solved:
How to hook up javascript to the client-side click of the Delete link.
How to know what item the user clicked Delete
Prevent a post-back
Delete the row that the user clicked
That is my question.
From here on you will find my rambling attempts to solve it. Don't take anything below as relating in any way to any possible accepted solution. Just because i posted code below, doesn't mean any of it is useful. And it doesn't mean i'm anywhere within spitting distance of the best solution. And because i can't make anything below work - it must have gone down the wrong road.
My Attempts
Wiring Up Javascript
The first task is to convert the delete link HTML from something such as:
<A href="DeleteItem.aspx?ItemGuid={19a149db-5675-4eee-835d-3d78372ca6f9}">
Delete
</A>
into something more javascripty:
<A href="#"
onclick="DeleteItem('DeleteItem.aspx?ItemGuid={19a149db-5675-4eee-835d-3d78372ca6f9}')">
Delete
</A>
and the add the script:
<script type="text/javascript">
//<![CDATA[
function DeleteItem(deleteUrl)
{
//Ask the user if they really want to
if (!confirm("Are you sure you want to delete INSERT NAME HERE?"))
{
return false;
}
//Call returns false if the server returned anything other than OK
if (!DoAjaxHit(deleteUrl)
{
return false;
}
//Remove the table row from the browser
var tableRow = document.getElementById("TODO-WHAT ID");
if (row != null)
{
//TODO: how to delete the tableRow from the DOM tree?
//document.Delete(tableRow) ?
}
//return false to prevent a postback
return false;
}
//]]>
</script>
What combination of ASP code can be used to create the above? i hear that asp:LinkButton has an OnClientClick event, where you can wire up a javascript function:
<asp:LinkButton ID="linkDelete" runat="server"
Text="Delete"
OnClientClick="DeleteItem(<%# GetDeleteUrl((ActionItem)Container.DataItem) %>);"/>
Problem is that the rendered HTML is literally containing:
<a onclick="DeleteItem(<%# GetDeleteUrl((ActionItem)Container.DataItem)) %>);" ...>
Delete
</a>
If i change the client click event handler to:
OnClientClick="DeleteItem('todo - figure this out');"/>
it works - as well as "todo - figure this out" can work.
Preventing Postbacks
The dummied down above javascript call actually happens (i can see my alert), but there's the next problem: Returning false from the javascript function doesn't prevent a postback. In fact, i can see that the href on the generated html code isn't "#", but rather
javascript:__doPostBack('ctl0....
i tried changing the ASPX code to include the OnClick handler myself:
OnClick="#"
OnClientClick="DeleteItem('todo - figure this out');"
But the compiler thinks the pound side is a pragma, and whines:
Preprocessor directives must appear as
the first non-whitespace character on
a line
Table Row Identity
The table rows don't have an ID, they're generated by the asp:repeater.
How can the javascript function know what triggered the click event? The javascript needs to be able to find the element, and remove it from the tree.
Note: i would of course prefer fade+collapse animation.
Normally you get an element by using
var tr = document.getElementById("the table row's id");
But the table rows don't have an easily knowable ID. Since there are multiple rows, the server generates the ID as it builds the table. i realize some solution is going to have to involve changing:
<TR>
into
<TR runat="server">
so that there will be server generated identity for each table row, but how do i reference the generated name from javsscript?
Normally i would have thought that the scripting problem would be solved by using multiple paramters:
function DeleteItem(tableRowElement, deleteUrl)
{
//Do a web-hit of deleteUrl to delete the item
//remove tableRowElement DOM object from the document tree
}
But the problem is just pushed elsewhere: How do you populate tableRowElement and deleteUrl for the call to the javascript function?
Such a simple problem: convert a click from a postback to client-side.
The volume of problems involved is getting quite idiotic. Which seems to indicate that either
the idea solution is something completely different
there is no solution
References
Stackoverflow: How do I fade a row out before postback?
Stackoverflow: Javascript before asp:ButtonField click
asp.net: Accessing repeater elements from javascript.
Stackoverflow: How to access repeater generated elements?
jQuery can dig out the tags for you:
$("[id$=linkDelete]").click(function() {
DeleteItem(this.href);
});
That code says "find all the DOM elements whose ID ends with 'linkDelete' and wire up the following click event handler".
I would recommend against implementing the Delete function through links in this way. Delete links are a security risk.
Rather, it's better to require a post to that url instead. If you want to be doing ajax, I would strongly recommend using a javascript framework so you don't have to deal with the differences in how different browsers implement XmlHttpRequests.
For instance, in jQuery you could do it like this:
$.post('Delete.aspx',{itemGuid:'{19a149db-5675-4eee-835d-3d78372ca6f9}'},
function(data, textStatus) {
if (textStatus == 'success') {
$(this).parents('tr:eq(0)').fadeOut();
}
});
which would do both the ajax call and the fadeout effect you want.
You could then access the item guid in Delete.aspx from Request.Form["itemGuid"], and this wouldn't be vulnerable to link attacks.
Preventing Postbacks
The server is generating a postback wireup because you're using a server control. Use a plain <a> tag without a runat='server' directive.
Table Row Identity
I usually do this by databinding an ID column of some kind and putting this in the repeater template:
<tr id='<%#Eval("ID")%>'>
P.S. I hate to sound like a fanboy, but jQuery will make all of these things an order of magnitude easier. You should really consider it if you can. Otherwise, you're going to be in a world of hurt trying to implement these features in a consistent way across browsers.
P.P.S. If the Delete.aspx and similar urls are only going to be called from javascript, I would recommend using ashx http handlers instead. You can do all of the same server logic without the needless overhead of a full-blown page.
mine usually comes out looking like
<asp:LinkButton runat="server" OnClientClick='<%# Eval("ID", "DeleteItem(this, \"{0}\"); return false;") %>' Text="Delete" />
that will make html that looks like
<a id="blah_blah_ctl01" onclick='DeleteItem(this, "{19a149db-5675-4eee-835d-3d78372ca6f9}"); return false;'>Delete</a>
I include the "this" reference so that you can have access to the dom and delete the link...or it's parent or whatever. From there it's pretty straight forward to use jQuery to actually do the posting and DOM manipulation. The "return false;" disables the postback.
The other answerers found various bits related to different aspects of the question. i managed to cobble together a complete solution. i've copy/pasted the relavent snippits here.
The first important change is the use of an asp:LinkButton which allows as OnClientClick event, which gives you direct access to the javascript OnClick event:
<asp:repeater ID="itemsRepeater"
OnItemDataBound="itemsRepeater_ItemDataBound"
runat="Server">
<itemtemplate>
<tr>
<td>
<asp:HyperLink ID="linkView" runat="server"
Text="<%# GetItemText((Item)Container.DataItem) %>"
NavigateUrl="<%# GetViewItemUrl((Item)Container.DataItem) %>" />
</td>
<td>
<asp:LinkButton ID="linkImpregnate" runat="server"
Text="Impregnate"
OnClientClick="<%# GetImpregnateUrl((Item)Container.DataItem) %>" />
</td>
</tr>
</itemtemplate>
</asp:repeater>
The code-behind manually builds presentation code (yay for separation of controller and view!) that contains a javascript call.
protected string GetNodeAcknowledgementClientClick(Item item)
{
if (!(item is HotGirl))
return ""; //this shouldn't be called for non-acknowledgements, but i won't fail
HotGirl girl = (HotGirl)item;
String szOnClientClick =
"return ImpregnateGirl(this, "+
Toolkit.QuotedStr(girl.GirlGUID.ToString()) + ", "+
Toolkit.QuotedStr(GetItemName(item))+");";
return szOnClientClick;
}
And finally in the aspx, i find a random spot to mash in some javascript:
<script type="text/javascript" src="Javascript/jquery.js"></script>
<script type="text/javascript">
//<![CDATA[
function DeleteItem(sender, girlGuid, girlName)
{
if (!confirm("Are you sure you want to impregnate "+girlName+"?"))
{
return false;
}
$.post(
'ImpregnateGirl.aspx?GirlGUID='+nodeGuid,
function(data, textStatus) {
if (textStatus == 'success')
{
$(sender).parents('tr:eq(0)').hide();
}
else
{
return false;
}
}
);
//return false to suppress the postback
return false;
}
//]]>
</script>
i would have made the jQuery do a post, as a security measure as guy suggested, but jQuery would give an error, rather than posting. Rather than care i chose to not care.