Preventing more than 1 clic on a form

[mmaisterrena]

Im having trouble with a form that saves inserts new record to a table a then automaticaly sends an email, the promblem occurs because users some times press the submit button more than once and this causes the record an the email to execute more than once, i have tried several aproaches to try to prevent this but so far i havent had seccess, can someone help with this problem.

[Doug Page]

Re: Preventing more than 1 clic on a form

How about making the first action to disable the button and the last action to re-enable it again. That way it would do nothing until your script runs completely through.

[mmaisterrena]

Re: Preventing more than 1 clic on a form

That sounds like a good idea, how can I de-activate the submit button on the form?

[Steve Wood]

Re: Preventing more than 1 clic on a form

Disabling the button would require javascript. An easier all-A5 approach would be to change the xbasic under that button. Have it ONLY open a new A5W page. On the A5W page, do your processing while a animated GIF perhaps says "Wait!". Then when the processing is done, return them to their original page (or some other page). If you use this method, the original button will immediately disappear and they cannot click on it.

[mmaisterrena]

Re: Preventing more than 1 clic on a form

Steve I tried that aproach but it seems that the browser doesnt goes to the next a5w page until it is fully loaded and considering that the xbasic code is loaded before the html (I think) theres no practical diference between putting this "Now loading" page and not doing so.

Unless im doing somethin wrong.

[Steve Wood]

Re: Preventing more than 1 clic on a form

Here's a different idea (not tested). When they click the button, test for a session variable. If it does not exist, create the variable, run the script and then delete the variable. As below:

if eval_valid("session.isrunning")
'do nothing
else
session.isrunning="YES"
..run the script
delete session.isrunning
end

[Peter.Greulich]

Re: Preventing more than 1 clic on a form

Steve,

That sounds like a good idea, but I think you need to reorder the script as shown below. Otherwise, the variable is still valid until the script finishes.

if eval_valid("session.isrunning")
'do nothing
else
session.isrunning="YES"
delete session.isrunning
..run the script
end

[Steve Wood]

Re: Preventing more than 1 clic on a form

It needs to be valid until you want the button to be active again. In fact, the script has to finish by moving the user away from this button, to a new page, etc. before deleting the session variable. Otherwise, they could just click the button again after the script finishes. Deleting the session variable has to come after the script runs, and after the page moves away from the dialog. That means deleting the session variable may not even be inside the IF THEN in my example. Deleteing the session variable may be done in whatever page is designed to come up after the script runs. For that matter, if this particular button is only pressed once per login (if that's the case) you could ignore deleting the session variable and that would only allow that script to run once per login.

[Peter.Greulich]

Re: Preventing more than 1 clic on a form

It needs to be valid until you want the button to be active again.

Sorry to be thick-headed, I don't follow the logic here. What do you mean by "until"?

[Steve Wood]

Re: Preventing more than 1 clic on a form

"Until", same as "I don't want the button to work until next time I want it to work".

I built a prototype for this that will work for all occassions using a Dialog component. The button will only fire ONCE for each time the dialog is called. It will not even fire a second time if the browser is refreshed:

Initialize Event:
delete session.isclicked

Validate Event:
if eval_valid("session.isclicked")
CurrentForm.Has_Error = .t.
CurrentForm.Error_Message = "Hey! You already pressed that button."
else
..any other validation code
end if

AfterValidate Event:
session.isclicked="True"
..any code here

[Peter.Greulich]

Re: Preventing more than 1 clic on a form

Thanks for that, Steve.

[mmaisterrena]

Re: Preventing more than 1 clic on a form

I think that would do it, ill try that
thank you Steve

[Steve Wood]

Re: Preventing more than 1 clic on a form

Just happend to tweak this; if you leave out the line starting with "CurrentForm.Error_Message=", it works more intuitively. With that line gone, the button still only works once no matter how many times you click it, but does not pop up any 'warning'. Looks better.

[Paul Velke]

Re: Preventing more than 1 clic on a form

I have tried various versions of this with limited success. No matter how I do it, it works if you wait a few seconds between button clicks, but if you click it twice fast it still runs AfterValidate and we get duplicate table entries.

I have about 8 checks going on in the Validate section and it could be why. It almost seems as if WAS wants both Validate requests to finish, then runs AfterValidate concurrently.

The only method I have found that consistently works is to disable the button with JavaScript. I would rather not do it this way for obvious reasons, but it is the only way I could stop the duplicates. I use the method in this thread as a backup to the JavaScript.

[Steve Wood]

Re: Preventing more than 1 clic on a form

You might post some of your code here, because I can't see how it would not work. When you click the Submit button it has to run the Validate event first. If that event triggers an error, which it should given my example, then the aftervalidate cannot possibly run.