Data Table Bindings
The Data Table Format may also define one or more bindings. Data Table bindings are similar to formulas in electronic spreadsheets (like Microsoft Excel). They define relationships between cells in the table. If the value of an "input" cell changes, the values in other cells that are bound to it are recalculated.
A data binding points to an output cell in the data table (i.e. the "left" part of the binding expression, or "binding target"), and derives its value from an input expression (which can contain references to one or more data sources or table cells). When such a data source (used as an input for the binding expression) changes, the binding is automatically re-evaluated, and a new value is posted to the output cell.
Creating Bindings
In most cases, bindings are added to the table format programmatically, e.g. when creating a device driver or writing a server script. See Working with Data Tables for details.
However, in some cases bindings are created by system operators using the Data Table Editor. These bindings are then used to modify tables on-the-fly without operator intervention, e.g. during a headless action execution.
Binding Target
The binding's Target field has the following syntax:
variable$field[row]#property
All elements of the binding target are optional, except for the field. It indicates the field in the table to which changes should be applied.
If a variable is specified, we've just created a cross-table binding. This is a binding in which values stored in one Data Table are copied into another Data Table. Such a binding will work only if the values of both variables are being edited within a single Edit Properties UI Procedure.
If row is not specified, the binding will be applied to every row in the table.
If property is not specified, the evaluation result is written to the field. Properties are used to modify the behavior of a given field when it's being edited. You can use them to conditionally enable/disable the field or to make a field into a drop-down list. Supported properties:
Property | Explanation |
enabled | Binding expression should resolve to a Boolean value in this case. If this value is TRUE, editing of the cell specified by the binding target will be enabled, otherwise, this cell will be switched to read-only mode. |
hidden | Binding expression should also resolve to a Boolean. If it is TRUE, the table field specified by the binding target will be hidden and its editing will not be allowed. Field hiding is only supported for single-row tables. |
choices | Binding expression should resolve to a Data Table containing a list of Selection Values that will be available for the cell pointed by a binding target. |
options | Binding expression should resolve to a String that represents new editor options for the field. |
Binding Expression
The binding expression may contain only standard references. If a reference points to a cell within the table being edited, it will resolve to the value currently contained in the cell (which may be edited by a user, or written by other binding). In all other cases value will be retrieved from the server context, as described in standard references section.
Data Table Bindings Resolution Environment: | |
May vary, see individual Data Table bindings processing cases for details. | |
Current table, i.e. the table on that the bindings are evaluated. | |
Current row, if the binding does not refer a specific row and is evaluated for each table row individually. Zero otherwise. | |
May vary, see individual Data Table bindings processing cases for details. | |
Example
recipient#enabled = {mailSendingEnabled}
When this binding is processed, editing of the recipient field (probably, e-mail recipient) is enabled for a user only if the Boolean field "mailSendingEnabled" contains a TRUE value (i.e. mail sending is enabled).
If a Data Table has several records, this binding will apply to every record separately.
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