Error rule

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

Syntax

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

Where:

'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).

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

condition
         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.

Scope

Objects: Transaction

Samples

Customer                  
{                                   
    CustomerId*         
    CustomerName   
    CustomerLastName
    CustomerAddress
    CustomerPhone
    CustomerBirthDate      
}

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;

Sample #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

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

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.

Sample #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).

See Also

Rules in Transactions