List:
Email | Flag |
| abc@gmail.com | Yes |
| def@gmail.com | No |
let's say you maintain a list like this.
App.OnStart:
Set(varUser,User());
Set(IsUser,LookUp(ListName,Email=varUser.Email && Flag.Value ="Yes"));
The above code will store user's info into variable if he is in the list and flag value is Yes.
Then next line on App.OnStart:
If(IsBlank(Navigate(HomeScreen),Navigate(Access Denied Screen));
The above line of code will check weather the variable is blank or not. If it is blank that means user's flag is No and he is coming for the first time to submit data. it will navigate him to home screen. If variable is not blank that means he is coming again. and will navigate him to access denied screen.
When you take the user's input make this flag YES.
Flag is nothing but choice type column which have two values Yes and No. By default it will be No
