Documentation:OCLOperators PSEval: Difference between revisions

OCLOperators PSEval

Revision as of 08:10, 3 March 2023

Makes it possible to use oclPS in any OCL expression. Using this, you can "reach into" the database from OCL and action-language (EAL).

Expression template:

SomeClass.PSEval(<ps-expression>,maxfetch,offset,<dependon>)

Note! - PSEval doesn't subscribe on sets from DB. To make the operator auto-updating, provide an expression in "dependon" that, when changed, should also rerun the PSEval expression. This can, for example, be a timer.

Example:

Uppdrag.PSEval(self.Uppdrag->select(u|u.Aktivt)->orderDescending(u|u.Startdatum),  1000, 0, self.Uppdrag)

For example, this expression from a method has "userName" as a parameter:

SysUser.PSEval(SysUser.allinstances->select(su|su.Username=userName),2,0,'')

Always remember that your SQL-server might also need indexes and other performance settings to execute your expression efficiently.

@@ Line 1: / Line 1: @@
-A way to switch from ocl to oclps in any expression.
+Makes it possible to use oclPS in any OCL expression. Using this, you can "reach into" the database from OCL and action-language (EAL).
-SomeClass.PSEval(SomeClass.allinstances->select(x|x.name=vWhatever),maxfetch,offset,dependon) -  offers a way to reach into the database from ocl and action-lang - beware that we dont subscribe on sets from db, send things to subscribe on dependon.
+Expression template:
+ SomeClass.PSEval(<ps-expression>,maxfetch,offset,<dependon>)
+'''Note!'''  - PSEval doesn't subscribe on sets from DB. To make the operator auto-updating, provide an expression in "dependon" that, when changed, should also rerun the PSEval expression. This can, for example, be a timer.
-For example this expression from a method having "userName" as a parameter
+Example:
+ Uppdrag.PSEval(self.Uppdrag->select(u|u.Aktivt)->orderDescending(u|u.Startdatum),  1000, 0, self.Uppdrag)
+For example, this expression from a method has "userName" as a parameter:
   SysUser.PSEval(SysUser.allinstances->select(su|su.Username=userName),2,0,<nowiki>''</nowiki>)
-See also [[OCLOperators Sqlpassthrough|Sqlpassthrough]]
+Always remember that your SQL-server might also need indexes and other performance settings to execute your expression efficiently.
+See also: [[OCLOperators Sqlpassthrough|Sqlpassthrough]], [[OCLOperators PSEvalValue|PSEvalValue]]
+[[Category:OCLOperators]]