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Avatar of dba123
dba123

asked on

UpdatePanel with HTML problems

               <tr>
                    <td align="right" valign="top">
                        <asp:label id="CurrentCourses" runat="server"></asp:label>
                    </td>
                    <asp:updatepanel id="CurrentCoursesUpdatePanel" runat="server">
                        <contenttemplate>
                            <td valign="top">
                                <asp:listbox id="CurrentCoursesList" runat="server" height="66px" width="214px" />
                                <br />
                                <asp:button id="AddCurrentCourse" runat="server" width="63px" />
                                <asp:button id="RemoveCurrentCourse" runat="server" width="83px" />
                            </td>
                        </contenttemplate>
                    </asp:updatepanel>
                </tr>
Avatar of mzalewski
mzalewski

Hi
Not sure what your problem is (you didnt post a description :)) - but I'm pretty sure that the ASP:UpdatePanel uses a DIV tag to wrap it's contents.
This would translate into invalid HTML:
<tr>
                    <td align="right" valign="top">
                        <asp:label id="CurrentCourses" runat="server"></asp:label>
                    </td>
                    <div id="CurrentCoursesUpdatePanel" >
                            <td valign="top">
                                <asp:listbox id="CurrentCoursesList" runat="server" height="66px" width="214px" />
                                <br />
                                <asp:button id="AddCurrentCourse" runat="server" width="63px" />
                                <asp:button id="RemoveCurrentCourse" runat="server" width="83px" />
                            </td>
                        </div>
                </tr>

Try this instead:
      <tr>
                    <td align="right" valign="top">
                        <asp:label id="CurrentCourses" runat="server"></asp:label>
                    </td>
                    <td valign="top">
                         <asp:updatepanel id="CurrentCoursesUpdatePanel" runat="server">
                             <contenttemplate>
                                   <asp:listbox id="CurrentCoursesList" runat="server" height="66px" width="214px" />
                                <br />
                                <asp:button id="AddCurrentCourse" runat="server" width="63px" />
                                <asp:button id="RemoveCurrentCourse" runat="server" width="83px" />
                             </contenttemplate>
                         </asp:updatepanel>
                      </td>
                </tr>
Avatar of dba123

ASKER

ahh, thanks! will try the div.  Not sure why DIV is so special in this case though.
ASKER CERTIFIED SOLUTION
Avatar of jinn_hnnl
jinn_hnnl
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OMG... I had commented and forgot to post it >.< when I do... there were already 2 .... sorry I didn't mean to spam this way
Avatar of dba123

ASKER

no, no problem.  I'm just wondering why a div is needed at all in this case...seems like overkill.
Avatar of dba123

ASKER

I think I just had some other issues.  I cleaned up my html.  I don't see a need for a div.  This works just fine now.  He're an example now of one of my table rows:

                <tr>
                    <td align="right" valign="top">
                        <asp:label id="Highest" runat="server"></asp:label>
                    </td>
                    <td align="left" valign="top">
                        <asp:updatepanel id="HighestUpdatepanel" runat="server">
                            <contenttemplate>
                                <asp:listbox id="HighestList" runat="server" width="214px"/><br />
                                <asp:button id="AddHighest" runat="server" width="63px" />
                            </contenttemplate>
                        </asp:updatepanel>
                    </td>
                </tr>
Well, the div is used as a placeholder for the content. The UpdatePanel is refreshed using javascript (AJAX) - once it has the new content, it needs somewhere to place it on the page. This can be done by finding the placeholder (the DIV element with the id 'CurrentCoursesUpdatePanel'), and replacing the old inner HTML with the new HTML.
Without this DIV element, it would not be possible to update it this way.
Yes, thats what jinn_hnnl and I were pointing out - The UpdatePanel should be placed inside the TD element, not the TR.

I think you might have misunderstood my original post - The first html example I gave was what the output would look like (from your code).
The DIV element is rendered by the UpdatePanel control - All ASP.NET WebControls have a tag property that determines the HTML tag to use when rendering the control to the output page. This is set by the developers of the control. The UpdatePanel has it's tag set to DIV.
This means that whenever an UpdatePanel is rendered, its contents are in a DIV container.

This was where you were having the problem - in HTML, a TR element cannot contain a DIV child element. This would have caused problems when the browser tried to display it (it was probably out of place).
The UpdatePanel needed to be moved inside the TD element before it could produce valid HTML.
yeahh after I posted (without knowing there were already one post with similar content), I said sorry for spaming. Because what I saw was the answer of first mzalewski is very similar with mine.

I meant the accepted answer should have belonged to him, and mine can be assisted. But thanks for the credit (and we will both happy if mzalewski can help some credit too ^^).

Well about updatePanel and the div. I am not sure whether it works without div or not (I think dba123 solution still works). But if you put it outside of the table, it looks nicer, and ... it might cover more part that needed. (you can apply this for more cases).
It's ok - my original post was a bit confusing (I think he thought I was saying to place it inside a DIV element, which isn't what I meant :))

Next time, I'll be sure to explain things properly if I want the credit for it :)