Introduction
Tip:
To better understand how Expressions work, check out the Use Expressions page in the How To section.
Expressions are comprised of several operations allowing you to transform, modify, and compute the data within an app in order to return an output result. Expressions can be used in several scenarios, such as:
- Bind to variables, process output, and other control values from the resources panel.
- Concatenate strings using the
&symbol. - Perform comparative operations.
- Create logical operators within comparative operations.
- Set control values through the
Iffunction added to comparative operations. - Perform arithmetic operations with the help of expressions.
- Declare static data such as "String", true/false, 123, etc or static lists of primitives such as a list of strings.
- Control hidden, disabled, font/background color properties.
- Reference a selected record or field on a record from another control.
Configuring expressions
The following operations can be used when configuring expressions:
- Functions
- Named Operators
Functions
You can check all the functions currently available for Apps in the About Functions section.
Operators
In addition to functions, Apps expressions also supports mathematical and conditional operators. For supported operators, see the table below.
| Category | Operator |
|---|---|
| Additive expression | +, - |
| Atomic expression | (), Literal, Variable, Functions |
| Comparison expression | <, <=, >, >=, in |
| Concatenation expression | & |
| Equality expression | ==, != |
| Exponentiation expression | ^ |
| Logical expression | &&, and, AND, | |, or, OR |
| Multiplicative expression | *, /, % |
| Unary expression | !, not, NOT, unary +, unary - |
Where can expressions be used
Expressions can be used for the following:
- Controls
- Rules
Controls
Expressions are enabled for hidden and disabled properties for the following controls and their display values:
- Button - Text (icon not supported)
- Checkbox - Label, Checked
- DatePicker - Hint Text
- Dropdown - Hint Text, Default Selected
- Switch - Label, On
- Text Area - Default Text, Hint Text
- Textbox - Default Text, Hint Text
- Label - Text
- Header - Text
- Image - URL
Note:
When used on control properties, expressions are re-evaluated at runtime if any of their dependent values changes.
Rules
Rules are used to enable conditional logic. You can use expressions on the following rules:
- If - Compare, Group
- Open URL - URL
- Show Message - Title, Message
- Show/hide spinner - Message
- Start process - Input override
- Set Value - Value
Note:
Expressions are not reevaluated continuously when used in rules, only at the time that the rule is triggered.
Updated 4 months ago
See Also
| Using Expressions |
| About Functions |