Validating an attribute based on the value of another while inserting

Question

Hi guys
I need to validate an attribute based on the value of another attribute.
Example:
inside some entity I have the following validation function
public boolean validateAtt1(Number data){
     if (this.getAtt2() < some vlaue)
          return false;
     return true;
this function works fine when I'm updating a record, but when I'm inserting a new record the this.getAtt2 return null, now I don't want to override the validateEntity function I want to override the validate function for att1; so in other words is there a way to reach att2 in the validation function of att1 when I'm inserting a new record, because the this.getAtt2() returns null if I'm inserting a new record.

Answer 1

Using attribute-level setter methods won't work because when the value of a particular attribute is being set, the values of the other attributes might not yet have been set. This explains for example why it does not work when inserting a new record. You therefore have to validate at entity level.
Rather than coding on the validateEntity() method you use a built-in Validator or Method Validator. When recording validators like this, you can provide a separate message for each business rule. If you also have the bundled exception mode enables (which will be the case by default for web applications), then multiple messages can be shown at the same time.
If you have one business rule involving two different attributes, for example a and b, and you must provide different messages based on if a is causing the violation or b, you can do it like this:
- implement one method doing the validation and that will indicate which attribute is causing the violation
- implement two different method validators (with two different messages) that call the method doing the actual validation and return false based on the attribute causing the violation
For more information about implementing business rules in ADF BC, you might have a look at this white paper:
http://www.oracle.com/technology/products/jdev/collateral/papers/10131/businessrulesinadfbctechnicalwp.pdf
Jan Kettenis