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Logic to lock out options

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Posted on by pgeory

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Good morning all, I have asked this question before but I am having to ask it again. I have an app for exam registration.

Our exams officer can create an event/exam with the following information. once submitted it is displayed like this.

An invigilator can then click on the register button and can choose from the role that they want to do see below.

I have now registered for the reader scribe and notice that it is showing that on the screen below.

What i would like to happen now is if someone else goes to register for this exam the option for reader/scribe is no longer available because its limit has been reached and the same for all the other options. Can anyone please provide me with a dummies guide on how i can achieve this. The data is being displayed in 2 different sharepoint lists. this is the list where the exam details are stored.

and this is the list for when someone registers for the exam

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AR-29081311-0 137 on at

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Hi @pgeory ,

I don't think it is possible or I am not aware on how to make a Choice column option from SharePoint "no longer available" as it will remain an option in the backend, therefore always pulling into the dropdown column.

You will need to handle the logic on the Save button. Or you could display a label when the user selects an option and the limit has been reached.

For example:
1. Put a label under your dropdown with text "The limit for this role has been reached!"
2. Set the visible property to: showLabel
3. Add code onSelect of the Dropdown that retrieves the limit from your Exam column, Checks how many people have currently registered for that role and then does the logic to hide/show the label.
4. You may want to use this logic on the displaymode of your save button also to disable the option to save if the limit has been reached.

This may not be entirely correct but you can make adjustments to suit your lists:
OnSelect of Dropdown Code:
// When a role is selected from the dropdown OnSelect = // Get the selected role Set(selectedRole, Dropdown.Selected.Role); // Get the limit for the selected role from the 'Exams' list Set(roleLimit, LookUp(Exams, Title = selectedRole).Limit); // Get the number of existing registrations for the selected role Set(existingRegistrations, CountRows(Filter(ExamRegistrations, Role = selectedRole))); // Check if the limit has been reached If(existingRegistrations >= roleLimit, // If the limit has been reached, display a label Set(showLabel, true), // If the limit has not been reached, hide the label Set(showLabel, false) )

Hope this helps!

Aaron

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Feline 92 on at

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Hi @pgeory

If I understand it correctly you want to filter the choices based on certain roles that are still required or not.

I always like to start by looking at the information that is available and find the logic accordingly.
What you know:
In this case you have the requirements in one list and the registrations in a second one.
This means that somehow you will most likely have to filter the second list based on known information to the two lists. In this case it could be the ExamID.
On the default form the choices from SharePoint are retrieved from the second list, default without any filtering

What you could do is create a temporary collection with the roles that are still required. For this you could check the filtered amount registered against the required. For example, if the filtered amount is smaller than the required, collect it to the temporary collection, like this:
If(

CountRows(Filter(Registrations, ExamID = Gallery1.Selected.'Exam ID' && Role.Value = "Lead")) < Value(Gallery1.Selected.'Lead Invigialtor'),
Collect(col_Options, {Value: "Lead"})

);
Depending on how you retrieved the registered amount in your overview screen, you could possibly reuse your own code.

Once you have the temporary collection you can filter the SharePoint choices based on that temporary list. For example as follows:
Filter(Choices([@Registrations].Role), Value in col_Options.Value)

This might not be the most performant way, but it gives you an idea of how you could create some logic yourself.
I hope this helps.

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pgeory 108 on at

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I am ot using dropdown I am using a datacard as i have it as form from sharepoint, does that make a difference. Sorry i am new to this and maybe bit off more than i could chew. Also do i put the code on the role datacard?

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Feline 92 on at

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Hi @pgeory

If you unlock the datacard for role on the properties panel, do you get something like this?
Choices([@YourList].Role

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pgeory 108 on at

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I get Items Choices([@'Exam Registration'].Role)

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Feline 92 on at

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Hi @pgeory

Great, this means that you get all the choice options from SharePoint.
So, this contains all the possibilities, now we need to adjust these options based on the roles we still need.

As a test we can try to put these roles in a separate collection.
To build this collection we need some way to check whether we have enough registered users per required role.
How do you retrieve the number of registered users per role in your overview screen?

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pgeory 108 on at

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pgeory 108 on at

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Where would i put this code?

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