Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people, just like you, are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
Solved

Javascript to show/hide panel but panel may not be visible on page load

Posted on 2008-10-10
4
920 Views
Last Modified: 2012-06-22
Hi
I have a user control, say called
MyUserControl

MyUserControl has a panel on it, panel1, and a combobox, NumberUnits

Depending on the value of "NumberUnits" (0-5) , Panel1 must be shown/hidden.


If numberUnits = 0, Panel1 should be hidden
else   panel1 should be shown


On page_load, the "NumberUnits" combobox is set to a value in session, say Session("NumberUnits")

On a page using master page I have two instances of these.  MyUserControl1 & MyUserControl2

On page_load of the MyUserControl I add javascript to the NumberUnits combobox like so. This means on changing the combobox, the panel is shown/hidden.
               js.Append("showHidePanel(")
                js.Append(Panel1.ClientID)
                js.Append(",")
                js.Append(NumberUnits.ClientID)
                js.Append(")")
                Me.NumberUnits.Attributes.Add("onchange", js.ToString)

HOWEVER there is a problem.

IF Panel1 is set to be hidden on loading, it is not rendered and so where the onchange event takes place nothing happens.

How do I get over this?
There are two things:
1) Panel1 must be able to be shown/hidden on changing NumberUnits combobox
2) Panel1 must be able to be shown/hidden on page load  [so it needs to be rendered even if not visible on page load]

Hope this makes sense.

Thansk in advance for assisting with code....hopefully I'm not way off with what I've done so far...
function showHidePanel(panel, unitsChosen)
    {
        // show the panel
        if (unitsChosen.value>0)
        {
            alert(unitsChosen.value);
            panel.style.visibility = "visible";
            
        }
        else
        {
            // hide the panel
            alert(unitsChosen.value);
            panel.style.display = "none"; //to hide it
        }    
    }

Open in new window

0
Comment
Question by:rwallacej
  • 2
  • 2
4 Comments
 
LVL 8

Accepted Solution

by:
tiagosalgado earned 500 total points
ID: 22687678
Instead of yourpanel.Visible = false, try to use yourpanel.Style.Add("visible","hidden")
0
 

Author Comment

by:rwallacej
ID: 22688092
thank you very much, for the benefit of others this works:

in .ascx.vb
                If NumberUnits.SelectedIndex = 0 Then
                    Panel1.Style.Add("visibility", "hidden")
                End If
 
in .ascx javascript
    function showHidePanel(panel, unitsChosen, model, iso, isoAmbient)
    {
        // show the panel
        if (unitsChosen.value>0)
        {
            panel.style.visibility = "visible";
        }
        else
        {
            // hide the panel
            panel.style.visibility = "hidden";
        }    
    }

Open in new window

0
 
LVL 8

Expert Comment

by:tiagosalgado
ID: 22688171
glad to help! Accept the solution pls.
0
 

Author Closing Comment

by:rwallacej
ID: 31505049
thanks - I got interrupted and forgot to accept solution
0

Featured Post

Free Tool: Postgres Monitoring System

A PHP and Perl based system to collect and display usage statistics from PostgreSQL databases.

One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

In Part 1 (http://www.experts-exchange.com/Programming/Languages/Scripting/JavaScript/A_7849-Hex-Maze.html) we covered the hexagonal maze basics -- how the cells are represented in a JavaScript array and how the maze is displayed.  In this part, we'…
The article shows the basic steps of integrating an HTML theme template into an ASP.NET MVC project
The viewer will learn the basics of jQuery, including how to invoke it on a web page. Reference your jQuery libraries: (CODE) Include your new external js/jQuery file: (CODE) Write your first lines of code to setup your site for jQuery.: (CODE)
The viewer will learn the basics of jQuery including how to code hide show and toggles. Reference your jQuery libraries: (CODE) Include your new external js/jQuery file: (CODE) Write your first lines of code to setup your site for jQuery…

856 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question