Expression designer is used for defining expressions of all types. Expression can be composed of prepared variables and predefined functions. Expressions can also be entered manually. Expression editor is used in numerous segments to define many properties or values in the adapter.
Expression editor can be found in sections
- Default Value in a scheme field.
- ReadOnly condition for a scheme field.
- Value Expression for a scheme field.
- Execution Condition for statements.
- Default Value for parameters in statements.
- Condition for audit trail.
The segment for which the expression designer is used defines which variables and functions will be available in the Expression Editor. Specific functions and variables are only visible in specific and appropriate segments.
Variables
Variables help defining expressions. They can be used in functions or be implemented only as a variable. Their values are used as a result for the expression. Variables are used to build expressions in Expression Editor. Variables can contain different types of data. Their values are information about something. Variables are listed in Expression Editor section under the node Variables. Variables are divided into two groups, settings variables and data source variables.
Settings Variables
Settings variables are variables which are defined in runtime environment. Several types of settings are available:
- Authorization
- Login
- Report
- Server Connectivity
- Identity
- Workplace Page
- Grid Print
- Information Panel Page
- Layout Page
- Localization
- Plant Level Page
- Server
Data Source Variables
Data source variables are fields in a specific data source. With selecting a field, its value is used in an expression. Double clicking the field it is transferred to the Expression Text section.
Functions
Expression function use variables or results of the function to create an expression. Constants can also be used for a function parameter.
Functions are divided into groups by their content. Functions are displayed in Expression Explorer section under the node Functions. To use a function double click it. Selected function appears in Expression Text window. In that window expression text is built. Information about currently selected function is also displayed in the bottom section of Expression Editor.