This section covers mouse drag-and-drop operations that greatly simplify binding component properties to data model items and to each other.
Drag and Drop Operations Between Entity Selector and Work Form
1. Dragging a variable field and dropping it on a component
In this case, two bindings are created:
| • | A binding that reads the variable field on startup and reset event of the root panel and writes it to the component's default property. |
| • | A bindings that writes the value of the component's default property back to the context variable upon the submit event of the root panel. |
2. Dragging a function input field and dropping it on a component
This operation creates one binding. Its target is a function's input field. Its expression is a reference to the default property of widget component. Its activator is the root panel's submit event.
3. Dragging a function output field and dropping it on a component
This operation also creates a single binding with a target pointing to a property of the component. The binding expression is a reference pointing to the output field of the function. Activator of this binding is submit event of the root panel.
4. Dragging a variable to the Data Table Editor component
This operation creates three bindings:
| • | A binding that reads the variable value on widget startup and writes it to the default property of the Data Table Editor, i.e. the table this editor operates on. |
| • | A binding that writes the table contained in the Data Table Editor back to the context upon the submit event of the root panel. |
| • | A binding that sets the Enabled property of the Data Table Editor according to the Writable property of the variable definition, to make sure that value of read-only variables can't be edited. |
5. Dragging a function to a Button component
This operation does not actually create new bindings. Instead, it finds all widget bindings:
| • | Whose target points to the input field of this function, or |
| • | Whose expression contains references to the output fields of this function |
and sets their activators to the action event of the button component. This makes them working together within one bindings processing session that is started upon button click (when action event is fired).
If a widget has no bindings related to the input or output fields of the dragged function, this drag and drop operation won't be allowed.
6. Dragging a variable field to a button group
This operation creates three bindings, which let you use the buttons in the group to change the field's value:
If the field has selection values, this operation also changes the Value property of all radio buttons that belong to the group to the available selection values. If you have 5 selection values (for example) yet only 3 radio buttons, only the first 3 values will be used - no error will be shown.
7. Dragging a variable field to Combo Box or List
This creates the same bindings as in 1 above (Dragging A Variable Field And Dropping It On A Component), but adds an extra binding whose purpose is to display the selection values defined by the field format in the combo box or list.
8. Dragging a Device Context and dropping it to any container
This drag and drop operation created a new Device component in the target container. The new component will have labels showing basic status of the dropped Device. It will also have a pre-defined Status Table configured to indicate current device connection status (Online, Offline or Suspended).
A binding linking server-side device status to the Status parameter of device component is also created.