In every single application you work on, you must apply some kind of mechanism to prevent the user to click twice in the same button when performing a single action.

If you ignore this fact, your application can behave unexpected and your data become corrupted.

But why this is a problem?

• Users are used to do double clicks, so you might expect that they will also double click on buttons or links;
• Users expect immediate feedback and some actions might take seconds to execute. If you don’t prevent the user to click the button again, he/she eventually will;

Let’s see an example:

As you can see:

1. I clicked the button, which triggered the company create action;
2. I didn’t receive any feedback, so I clicked the button again before receiving the answer from the server;
3. When the second request to the server was executed, the Company was already created and the application returned the respective error;
4. At last, we receive the response from the first call to the server with a success message;

This is obviously wrong and a bad user experience.

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What can we do to prevent this?

What I usually do is to use a local control variable named IsBusy (boolean):

and, in each button/link that performs any action that changes data, I force all buttons/links to be disabled when IsBusy = TRUE:

then, in each action that changes data, I set IsBusy = True before executing the action and IsBusy = False after executing the action:

Let’s see it in action…

As you can see:

1. I clicked the button, and the button is immediately disabled;
2. As the button is disabled, I cannot click it again before receiving the answer from the server;

This is obviously a better user experience and prevents unexpected results from the action being triggered more than once.

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You can test the working example here: https://tiagomlcdias.outsystemscloud.com/BlogArticles/PreventingDuplicateActionCalls

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Users be like: ‘If one click doesn’t work, surely two in rapid succession will confuse the computer into submission.’ 😄🖱️