Macros¶

Macros are placeholders that can be used in string-based property values. They are substituted at runtime, and before the property gets interpreted.

Macros use the syntax ${mymacro} or $(mymacro).

Predefined Macros

The following macros are predefined with special meaning:

$(DID)

Unique identifier for a display instance.

For example, if a display uses a local PV called loc://$(DID)_foo, each instance of that display will use a different local variable, without interfering with potential other instances of that display.

$(DNAME)

The name of the display.

$(LCID)

Unique identifier for a Linking Container instance. If a display contains multiple Linking Container instances referring to the same display, the $(LCID) macro will evaluate to a different unique value in each.

Property Macros

In the context of a widget, all of its properties can be accessed in other properties using property identifiers as the macro name. For example: $(pv_name), $(border_width), …

Custom Macros

You can define custom macros at different locations:

1. In user preferences under OPI Runtime.

2. In the configuration of an Open OPI widget action (or the equivalent ScriptUtil.openOPI script utility).

3. In the Macros property of a display.

4. In the Macros property of a container widget.

Macros are evaluated for each widget. If a macro with the same name is defined at multiple levels, they overwrite each other in the above order. For example: (4) wins from (1).

If the option Include macros from parent is unticked, macros from higher levels are not inherited.

Example

The Tooltip property of all widgets has the following default value:

$(pv_name)
$(pv_value)

When the display is running, the tooltip of widgets will show the value of the PV Name property, as well as its current value.