set the attributes in PHP 5 - php

Question

In my Zend framework I have two row one rows contains state dropdown with label state and the other contains a text box with label other state. Below is the code:
'state' => array('select', array(
'required' => true,
'decorators' => $elementDecorators,
'label' => 'State:',
'multiOptions' => $values["state"]
)),
'other_state' => array('text', array(
'required' => true,
'filters' => array('StringTrim'),
'decorators' => $elementDecorators,
'label' => 'Other State:',
'class' => 'other_state',
))
Here the other state is set as required. I need it required only when the user select "Other" value from the state drop down.

Answer 1

Client Side:
jQuery solution:
Showing your HTML output would have been a help here. But the following will add the attribute required if other is selected - this will also enable the input and disable it so the user can only enter something in other state, if they select other:
$("#state").change(function(){
if ($(this).val() == "other"){
$("#other_state").removeAttr("disabled");
$("#other_state").attr("required", "required");
}
else {
$("#other_state").removeAttr("required");
$("#other_state").attr("disabled", "true");
}
});
See a demo here
The above will do the validation on the clients side - with jQuery, however if the user has javascript turned off, it would allow the user to select other and leave other_state blank!
Server Side:
Zend solution:
What you should also do is add some validation to the zend_form. However, you can't add them the normal way - if you added a validator to say other_state can't be empty - you would have an error when a state is selected and you want it to be empty.
In your form class you could override the isValid call to add your custom validation, see the discussion here: There is another example on how to do this here
/**
/* override the isValid function of Zend_Form
/* to set a required field based on a condition
*/
public function isValid($value) {
// Check the key exists in the stack, and if its set to other:
if (array_key_exists('state', $value) && $value['state'] == 'other') {
// It is so make sure other_state is a required field:
$this->other_state->setRequired(true);
}
parent::isValid($value);
}