Custom Robust eval Function

 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+

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onCampaignLoad

<source lang="mtmacro" line> [ defineFunction( "eval", "evalFunction@this", 1, 0 ) ] </syntaxhighlight>

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evalFunction

<source lang="mtmacro" line> // Error handling [ assert( argCount() >= 1, "eval() - Invalid number of parameters 0,

                           expected at least 1 parameter.", 0 ) ]

// Initialise variables [ X_Expression_X = arg( argCount()-1 ) ] [ X_CancelEval_X = 0 ] [ X_TypeTest_X = json.type( X_Expression_X ) ]

// Handle all numbers [ if( isNumber( X_Expression_X ) == 1 ), code: {

  [ X_CancelEval_X = 1 ]

} ]

// Handle empty strings [ if( X_TypeTest_X == "UNKNOWN" ), code: {

   [ if( X_Expression_X == "" ), code:
   {
       [ X_CancelEval_X = 1 ]
   } ]

} ]

// Handle JSON types [ if( X_TypeTest_X == "ARRAY" || X_TypeTest_X == "OBJECT" ), code: {

   [ X_CancelEval_X = 1 ]

} ]

// Evaluate or cancel, then return [ if( X_CancelEval_X == 1 ), code: {

   [ macro.return = X_Expression_X ]

};{

   [ macro.return = oldFunction( X_Expression_X ) ]

} ]

</syntaxhighlight>

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