SRL Archive - OSR Intermediate Scripting Tutorials

[Tut] Using Custom Errors

LordJashin

2012-03-11 17:54:09

Custom Errors:

program CustomError;

begin

RaiseException(erCustomError, 'Epic fail');

WriteLn('haha you failed'); // This line never executes

end


This is what happens in Simba:



Explored example: 
program CustomError;

var
  ThrowFail : Boolean;
  Error: String;

  // Some might make their own procedure for Script Termination
  procedure FailThem;
  begin
    WriteLn('Failed to: ' + Error);
    //TerminateScript;
  end;

begin

  Error := 'Find Bitmap';

  FailThem;

// Someone might Terminate a script like so

  ThrowFail := true;

  if ThrowFail then
    begin
      WriteLn('Failed to $(#*&@%^)$#^%$#');
      WriteLn('Terminating Script');
      //TerminateScript;
    end;

(* Doing this also Terminates the script but has advantages, the
   line number is given and highlighted, and using this does a WriteLn
   only use this though if there's an error, and your script cannot go
   on because of it *)

   // This will output: Error: Epic fail at line 35 if ThrowFail is True

  if ThrowFail then
  RaiseException(erCustomError, 'Epic fail');

  WriteLn('haha you failed'); // This line never executes

[LEFT] [/LEFT]

Dervish

2012-03-11 17:56:27

Okay, pictures and so but… What use ?

masterBB

2012-03-11 18:11:11

From: Dervish
Okay, pictures and so but… What use ?


You can use it for debugging purposes. Like this:

if SomethingGoesTerribleWrong then
  RaiseException(erCustomError, 'Oh no, it went wrong');

Note that is does display the line at which the error occurred.

Brandon

2012-03-11 18:12:31

From: Dervish
Okay, pictures and so but… What use ?


It's a very short tut but very useful.. I do this in the waterfiends incase people do not have the right maps.. It stops a script from running..

It's almost the same as making your own procedure to shutdown and terminate the script.. except that it'll highlight the line where the problem has occured..

Usually NOT made for scripts but actually for Simba itself as this exception raising is for Runtime Compiling.. So Iunno if he's using it right or not..

Usually you want to raise an exception when the user pressed play and something is wrong.. Not while the script is running or else it can actually in some cases, cause a user to die if it's a fighting script as it will just terminate on the spot!

It's the exact reason that we use Try-Catch statements.. so that we can avoid pre-termination.. especially if u try to free a dtm that is already free or doesn't exist..

Advice.. Only do this at the start of a script IF needed..

LordJashin

2012-03-11 18:57:16

From: ggzz
It's a very short tut but very useful.. I do this in the waterfiends incase people do not have the right maps.. It stops a script from running..

It's almost the same as making your own procedure to shutdown and terminate the script.. except that it'll highlight the line where the problem has occured..

Usually NOT made for scripts but actually for Simba itself as this exception raising is for Runtime Compiling.. So Iunno if he's using it right or not..

Usually you want to raise an exception when the user pressed play and something is wrong.. Not while the script is running or else it can actually in some cases, cause a user to die if it's a fighting script as it will just terminate on the spot!

It's the exact reason that we use Try-Catch statements.. so that we can avoid pre-termination.. especially if u try to free a dtm that is already free or doesn't exist..

Advice.. Only do this at the start of a script IF needed..


And here I thought this was self explainatory :duh:. You could use this like for if Statements, to stop the script at that point and show an error. Might be useful, example: 


program CustomError;

var
  ThrowFail : Boolean;
  Error: String;

  // Some might make their own procedure for Script Termination
  procedure FailThem;
  begin
    WriteLn('Failed to: ' + Error);
    //TerminateScript;
  end;

begin

  Error := 'Find Bitmap';

  FailThem;

// Someone might Terminate a script like so

  ThrowFail := true;

  if ThrowFail then
    begin
      WriteLn('Failed to $(#*&@%^)$#^%$#');
      WriteLn('Terminating Script');
      //TerminateScript;
    end;

(* Doing this also Terminates the script but has advantages, the
   line number is given and highlighted, and using this does a WriteLn
   only use this though if there's an error, and your script cannot go
   on because of it *)

   // This will output: Error: Epic fail at line 35 if ThrowFail is True

  if ThrowFail then
  RaiseException(erCustomError, 'Epic fail');

  WriteLn('haha you failed'); // This line never executes

end.