We often want to "conditionally" do things in our app, for example if the value of a label is <0, we want it to be red. We can do things conditionally in our app using the if-then-else statement combined with conditional expressions.
In Apps Studio, the If-Then-Else rule allows you to specify:
- the condition(s) to check (that's goes in the If statement)
- what happens if the condition is true (that's goes in the Then statement)
- what happens if the condition is false (that's goes in the Else statement)
There are two kinds of conditional statements that can be used inside the If:
- Compare: Used to compare two values.
- Group: Used to group multiple comparisons (And/Or).
The compare function allows you to write a conditional expression - something that evaluates to true or false.
Each condition specifies two values to compare and a comparison operation.
These values can be:
- a reference to a control property
- a static value (i.e. a number or a string)
The comparison operation must be one of the following:
Returns true if the left value is less than the right value
3 < 6
Less than or equal
Returns true if the left value is less than or equal to the right value
Cash In Value ≤ 0
Returns true if the left value is greater than the right value
5 > 2
Greater than or equal
Returns true if the left value is greater than or equal to the right value
Cash Out Value ≥ 0
Returns true if the left value is equal to the right value
State = WA
Returns true if the left value is not equal to the right value
Transaction Id ≠ 0
The Group function allows you to combine multiple conditional expression together. This allows us to make more complex conditional expressions like "if both X and Y are true" or "if either X or Y are true" in our apps.
The Then and Else statements can be any rule, meaning you can nest statements.
Scenario: When the "Submit" button is clicked, a process runs and returns a transaction ID. The text color of the "Transaction ID" label should be red if the deposit is less than 0, otherwise it should be green.
Updated 26 days ago