The spooky ascetic Property
During my recent work on Tutorial - Working with %Query #1
I met a Class Property that is quite different from its same-named relatives.
It is there since 'ever' but is rarely used, Related doc doesn't help so much.
A typical property in a class looks similar to this:
Property City as %String;
And you have a rich choice of additional settings to define it
and provide an initial value.
If you save it, it gets validated and stored
Inside a persistent class, you get its content back
All well know features that don't require explanation to you as experts.
If you declare a property to be MULTIDIMENSIONAL nothing is as before.
It starts at the creation of your Class instance - it is just not there
It is created at the first assignment of any value.
As you see it has no DataType - but you miss nothing as it is never validated
And you won't find all data-type-related implicit methods as LogicalToODBC or similar.
On the other hand, you can use all the ObjectScript-Functions that are not
available or allowed for standard typed Properties:
- SET $BIT()
- SET $EXTRACT()
- SET $LIST()
- SET $PIECE().
- MERGE command
You just work with it like with a normal local variable in ObjectScript.
Multidimensional is a bit misleading.
You can create local variable arrays, but it is no requirement.
The price you pay for this freedom is:
It is YOUR job to save/load it for persistence if required.
And to initialize and validate it with your own code,