drupal javascript API & form set error

1.is there a way to do form_set_error in client side so if there is error in javascript validate it will set error and wont let user process the other steps? js can be disabled so i want to take extra cauti开发者_Python百科on...

1. where is a complete list of drupal javascript function reference like Drupal.t and stuff?

2. how can i change the error messages of form set error (the default errors like { fieldname... field is required } ?

3. how can i do errors that will show below/above/inline the field ?

JavaScript in Drupal, Covers the Drupal JavaScript API, AHAH forms, and the kind of stuff your looking for. The Quick start Guide is pretty good.

As for validation, you're right, Javascript can be turned off. JavaScript validation is mostly done for usability, since the user doesn't have to wait to POST his form in order to receive an error message. JavaScript lets him know in real time if for example, his password is too weak, or email invalid, before submitting the form.

JavaScript validation however is not good for security. That's where you will need to do server-side validation. form_set_error will take care of the server-side validation.

So if you have a form that looks like:

function form_foo($form_state) {
    $form['foo'] = array(
      '#type' => 'textfield',
      '#title' => t('bar'),
      '#default_value' => $object['foo'],
      '#size' => 60,
      '#maxlength' => 64,
      '#description' => t('baz'),
    );
    return $form;
}

The server-side validation would look like:

function form_foo_validate($form, &$form_state) {
  if (empty($form_state['values']['foo'])) {
    form_set_error('foo', t('Foo cannot be empty.'));
  }
}

If the bar textfield in the form is indeed empty, when the user submits the form bar will be highlighted, the 'Foo cannot be empty' error message will appear, and the form _submit hook won't be called.

For JavaScript functionality, the Overview of Drupal JavaScript API document has most of the information you will need.