Error rule

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Displays an error announcement and does not allow continuing with the execution while the condition is complied with.


Error('announcement' | &var | character_expression [,ExceptionName]) [ IF condition ] [ON triggering event];


'announcement' (or &var or character_expression)
         Is the phrase (string) you want to display when the condition is complied with.
        When using a variable or character_expression, GeneXus controls the resulting type is character (if not, it is adviced in the navigation report).

         If the transaction is configured as Business Component, the ExceptionName parameter can be set as the ID of the error to solve Error handling in Business Components

         Is any valid logic condition

triggering event
         Is one of the predefined events available in GeneXus for transaction rules, which allows you to define the precise time for executing a rule


Objects: Transaction


Example 1


Customer rules:

error('Enter the customer name please') if CustomerName.isempty();
error('Enter the customer last name please') if CustomerLastName.isempty();
error('The customer must be 18 years old or older') if CustomerBirthDate.age()<18;
error('Customers can not be deleted') if delete;

Example 2

Suppose the Customer transaction is configured as Business Component and the transaction has the following rule defined:

error('The customer must be 18 years old or older', 'CustomerMustBe18YearsOld') if CustomerBirthDate.age()<18;

The value referenced in the ExceptionName parameter will be charged in the &Messages collection variable based on the Messages SDT (in the "ID" property) which you can load using the GetMessages() method.

Example code:

&CustomerBc is a Customer variable

If &CustomerBc.Fail()
   &Messages = &CutomerBc.GetMessages()
    If &Messages.Item(1).ID = 'CustomerMustBe18YearsOld'

The ExceptionName parameter is an identifier, so it does not accept neither spaces, special characters: / : ” | = < > | nor Functions.

If the syntax is not correct, GeneXus will display the following compilation error:

xxx.cs(yy,yy): error CS0103: the name 'pushError' does not exist in the actual context.

Example 3

Working with the same Customer transaction, the following rule can be defined:

Error(&ReturnedText) if ProcedureCheck(&ReturnedText);

The previous definition is valid, but you must take into account that the variable &ReturnedText is considered a procedure input parameter. So, the rule will only be triggered if the variable is assigned (for example, if it is an output variable in another rule).

Note: When deleting a record from a Transaction, the rules won't execute unless you specify the condition "if delete".

See Also

Transaction rules