Custom Robust eval Function

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Revision as of 17:37, 17 June 2009 by Verisimilar (talk | contribs) (Updated and fixed.)
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 Note: This function can only be used in a Trusted Macro

This user defined function redefines the standard eval() function, allowing it to be given a number, empty string, or JSON object/array and not throw an exception.

Macros

Place both of these macros on the same library token.

1.3b56+


onCampaignLoad

[ defineFunction( "eval", "evalFunction@this", 1 ) ]



evalFunction

//  Error handling
[ assert( argCount() >= 1, "<b>eval()</b> - Invalid number of parameters <i>0</i>, expected at least <i>1</i> parameter.", 0 ) ]

//  Initialise variables
[ Expression = arg( argCount()-1 ) ]
[ CancelEval = 0 ]
[ TypeTest = json.type( Expression ) ]

//  Handle all numbers
[ if( isNumber( Expression ) == 1 ), code:
{
   [ CancelEval = 1 ]
} ]

//  Handle empty strings
[ if( TypeTest == "UNKNOWN" ), code:
{
    [ if( Expression == "" ), code:
    {
        [ CancelEval = 1 ]
    } ]
} ]

//  Handle JSON types
[ if( TypeTest == "ARRAY" || TypeTest == "OBJECT" ), code:
{
    [ CancelEval = 1 ]
} ]

//  Evaluate or cancel, then return
[ if( CancelEval == 1 ), code:
{
    [ macro.return = Expression ]
};{
    [ macro.return = oldFunction( Expression ) ]
} ]


1.3b51 - 1.3b55


onCampaignLoad

[ defineFunction( "eval", "evalFunction@this" ) ]



evalFunction

[h: assert( argCount() >= 1, "<b>eval()</b> - Invalid number of parameters <i>0</i>, expected at least <i>1</i> parameter.", 0 ) ]

[h: Expression = arg( argCount()-1 ) ]
[h: CancelEval = 0 ]
[h: TypeTest = json.type( Expression ) ]

[h: if( isNumber( Expression ) == 1 ), code:
{
   [h: CancelEval = 1 ]
} ]

[h: if( TypeTest == "UNKNOWN" ), code:
{
    [h: if( Expression == "" ), code:
    {
        [h: CancelEval = 1 ]
    } ]
} ]

[h: if( TypeTest == "ARRAY" || TypeTest == "OBJECT" ), code:
{
    [h: CancelEval = 1 ]
} ]

[h: if( CancelEval == 1 ), code:
{
    [h: macro.return = Expression ]
};{
    [h: macro.return = oldFunction( Expression ) ]
} ]