YENGtry
From OpenSimulator
There can not be any llResetScript, osResetAllScripts or llDie inside any of this blocks. script will compile but fail with a severe runtime error
try, catch and finally allow to handle some exceptions (see runtime exceptions) without getting the script killed.
- On the try block we place the code we want to run protected.
- On a catch blocks we place code to handle the exceptions
- On the finally block we place code that should always run.
- throw keyword allows a catch to reissue the exception, so the engine handles it normally
A try block must be follow by at least
one or two of the following catch types (possible more in future), one finally block all of those
at this time there are only 2 types of cache blocks
to catch script related exceptions
catch(scriptexception ex) { }
to catch any available exception a script can intercept:
catch(exception ex) { }
in both cases particular exception must be found by looking to the message.
The catch blocks types are checked by their order in source.
Only the first that matches the exception type is executed, so if both needed scriptexception should be first.
There are a few auxiliary functions.
string yExceptionMessage(exception ex)
returns a string with the message of the exception ex
string yExceptionTypeName(exception ex)
returns a string with system name of the exception. scriptexception will return ScriptException
so catch(scriptexception ex) could be
catch(exception ex) { if(yExceptionTypeName(ex) == "ScriptException") { ... } }
but catch(scriptexception ex) is faster and more readable
Examples
Make sure to include yoptions; on second line of script.
Silly example.
touch_start(integer nn) { integer a = 0; try { llSay(PUBLIC_CHANNEL,"try"); float c = 1 / a; } catch(scriptexception ex) { if(yExceptionMessage(ex) == "Division by Zero") llSay(PUBLIC_CHANNEL,"Where did you learn math?"); else throw; } finally { llSay(PUBLIC_CHANNEL,"finaly"); } }
Detect no ossl permission.
touch_start(integer n) { try { key agent = llDetectedKey(0); osForceOtherSit(agent); } catch(scriptexception ex) { string message = yExceptionMessage(ex); if(osStringStartsWith(message,"ossl permission error", TRUE)) llSay(PUBLIC_CHANNEL, "You need to enable osForceOtherSit on osslEenable.ini"); else throw; } }
