zend validation messages - zend-form

Question

consider the following part of a form
$name = new Zend_Form_Element_Text('name');
$name->setLabel('name: ')
->setRequired(true)
->addValidator($empty)
->addValidator($alpha)
->setDecorators($newdecorators);
$this->addElement($name);
I defined $empty and $alpha as:
$empty = new Zend_Validate_NotEmpty();
$empty->setMessage('some text', Zend_Validate_NotEmpty::IS_EMPTY);
$alpha = new Zend_Validate_Alpha();
$alpha->setMessage('some text',Zend_Validate_Alpha::NOT_ALPHA);
Now my question:
with this code I get a double validation message when the input is empty. First the custom message and then: '' is an empty string
When i drop the setRequired, the empty validator does not run. Why is this? I don't want to use the setRequired, because if i add an errorMessage for setRequired, the $alpha error message is overwritten.
thx,
J

Answer 1

This happens because the default behaviour is to check against all validators that are assigned to an element, even if one of the prior validations fails.
Luckily it is quite easy to prevent this: In the addValidator method you can pass a second parameter $breakChainOnFailure that stops further validation upon failure if set to true.
So in the example you gave, all you need to do is to set the second parameter to true:
$name = new Zend_Form_Element_Text('name');
$name->setLabel('name: ')
->setRequired(true)
->addValidator($empty, true)
->addValidator($alpha, true)
->setDecorators($newdecorators);
$this->addElement($name);
And only one error message is displayed in case you enter an empty string.
For further information refer to the Zend Framework Documentation on Validator Chains.