Blinking rows of a gridview on some condition

debsoft · July 29th, 2009, 01:25 AM

Dear Friends,
I'm working on a .NET web application wherein I have a gridview. The gridview gets refreshed after some time interval that is specified by user.
Now there is a Time column in the gridview which contains a number (in minutes). This column is invisible. The requirement is for the rows of a gridview to blink if the Time column for those rows has a value less than 120. So all the rows in the grid where the Time column has value < 120 should blink.
So let's say the first time when the page loads only the first five rows of the gridview are blinking (since they satisfy the above condition). Now after the gridview gets refreshed, two more rows get added from the DB and they satisfy the condition above. So in this case, the previous five rows plus the two new rows (7 in total) should blink.
I tried all sorts of javascript function but coudln't achieve this requirement. Can someone help me out with this??
Thanks in advance
Debsoft

Lee Dumond · August 1st, 2009, 03:05 PM

Don't think I've ever seen a blimking row before.

What do you mean when you say a row should "blink"? Do you meant just the background should blink, or the actual data and everything?

alliancejhall · August 2nd, 2009, 10:58 AM

I'm just assuming here but you could do something like this

Use javascript to perform the actual blinking.

Code:

window.onload = startBlink;

function doBlink() {
  // Blink, Blink, Blink...
  var blink = document.all.tags("BLINK")
  for (var i=0; i < blink.length; i++)
    blink[i].style.color = blink[i].style.color == "" ? "white" : "" 
}

function startBlink() {
  // Make sure it is IE4
  if (document.all)
    setInterval("doBlink()",1000)
}

then just add <BLINK></BLINK> tags around the Data you want to blink

So in your gridview you could do something like

Code:

        <asp:TemplateField HeaderText = "First Data Column">
        <ItemTemplate>
        <%= iif(cint(Eval("Time")) < 120,"<BLINK>" & Eval("FirstDataColumn").ToString & "</BLINK>", Eval("FirstDataColumn").ToString  %>
        </ItemTemplate>
        </asp:TemplateField>
        
        <asp:TemplateField HeaderText = "Second Data Column">
        <ItemTemplate>
        <%= iif(cint(Eval("Time")) < 120,"<BLINK>" & Eval("SecondDataColumn").ToString & "</BLINK>", Eval("SecondDataColumn").ToString  %>
        </ItemTemplate>
        </asp:TemplateField>

There may be better ways to do this but i'm just doing an inline if to see if the time is less than 120 if it is then i add the BLINK tags around the text value and if it's not then i just add the text value. Now this won't work if you need to edit the gridview but it's just readonly then I think it might work for what you need?

Lee Dumond · August 2nd, 2009, 11:23 AM

Jason -- you have the right idea, but using the <BLINK> tag wouldn't be cross-browser compatible. No version of IE has ever supported it.

I think you'd have to do this through CSS, by switching the visibility property from visible to hidden using a javascript timer as you've done.

Or better yet, what I would do is probably leave the data visible but just blink the background color of the row using the background property. This would allow the data to still be readable, but would accomplish the intended function of bringing attention to the rows in question.

alliancejhall · August 2nd, 2009, 02:25 PM

Hmm... i've used that code for a while and it does work in IE (IE6+ at least). Either way the concept should be the same so how ever they want to do it should accomplish the task. Thanks for the alternative Lee!

Lee Dumond · August 2nd, 2009, 02:38 PM

I assure you, the <blink> tag has never, ever worked in any version of Internet Explorer.

http://en.wikipedia.org/wiki/Blink_element

Apple Safari does not support it either.

It is supported by FireFox and Opera.

alliancejhall · August 2nd, 2009, 02:46 PM

I see what you are saying... I'm not expecting the tag to do the blinking i'm just using that tag to denote what you want to blink. I use the doBlink function just to find the blink tag instead of sending the id of what ever you want to blink. But yes you are right the "blink" tag doesn't work. I just use it as a locator for what i want to blink. I guess your way would be less confusing...

Lee Dumond · August 2nd, 2009, 02:50 PM

Oh right, I get you. That would work then.

I'd also point out that it still wouldn't validate (blink is not standards compliant) if that is important to you.