Conditional validation of attributes in extbase: Add errors manually - typo3

Question

I need to validate some fields based on values other fields have, within the same model. Since a custom validator only has access to the value it is validating, I can't check other validations there. From inspecting AbstractValidator, I couldn't find a possibility to reach that object the current value is validated.
Is there a solution to validate/add errors in a controller, set errors and render the actual view by keeping the original routine instead of introducing and assigning new objects to the view? Basically I could create a custom $errors var, fill it with errors after having done custom validations and the display it along with the original form errors. But I don't like that workaround approach.

Answer 1

When you add a new model validator, you have access to the other fields of that model
File: test_extension/Classes/Domain/Validator/TestModelValidator.php:
class Tx_TestExtension_Domain_Validator_TestModelValidator extends Tx_Extbase_Validation_Validator_AbstractValidator {
/**
* #param Tx_TestExtension_Domain_Model_TestModel $testModel
* #return boolean
*/
public function isValid($testModel) {
/** #var $testModel Tx_TestExtension_Domain_Model_TestModel */
//Access all properties from $testModel
$field1 = $testModel->getMyField1();
$field2 = $testModel->getMyField2();
}
}
You can also add errors to speific fields, but this code is from TYPO3 4.5, don't know if its still valid:
$error = t3lib_div::makeInstance('Tx_Extbase_Validation_Error', 'The entered value is allready in use.', 1329936079);
$this->errors['field2'] = t3lib_div::makeInstance('Tx_Extbase_Validation_PropertyError', 'field2');
$this->errors['field2']->addErrors(array($error));