Drupal 7 - Construct clean URL from form post - forms

Question

I am creating a custom module in Drupal 7 that is a job search. I am wanting to make it so you can specify a clean URL to perform the search like so:
www.example.com/job-board/cardiology/california
Where "cardiology" is the "specialty" variable and "california" is the "location" variable.
now I know how to do this as far as mapping the variables in my hook_menu and accessing the variables. The problem is how do I create a search form that creates the clean url when you submit it? In other words if I had this:
<form method="get" action="job-board">
<select name="specialty">
<option value="cardiology">Cardiology</option>
<option value="some_other_value">Some Other Value</option>
</select>
<select name="location">
<option value="california">California</option>
<option value="some_other_state">Some Other State</option>
</select>
<input type="submit">
</form>
and I submit it, it will go to www.example.com/job-board?specialty=cardiology&location=california instead of www.example.com/cardiology/california. How can I make the form construct a clean URL?

Answer 1

You should create that form using Drupal's Form API and assign a custom submit callback to it.
In that submit callback, you can perform validation and if everything is OK, redirect the user to the appropriate URL.
See the source code of Examples modules, specifically one related to Form API in order to learn more about it.
In short, here's what you would do:
/**
* Sample form.
*/
function MYMODULE_sample_form() {
$form['specialty'] = array(
'#title' => t('Specialty'),
'#type' => 'textfield',
'#required' => TRUE,
);
$form['state'] = array(
'#title' => t('State'),
'#type' => 'select',
'#options' => array(
'california' => t('California')
),
);
$form['actions'] = array('#type' => 'actions');
$form['actions']['submit'] = array('#type' => 'submit', '#value' => t('Submit the form'));
return $form;
}
/**
* Sample form submit processing.
*/
function MYMODULE_sample_form_submit($form, &$form_state) {
$specialty = $form_state['values']['specialty'];
$state = $form_state['values']['state'];
drupal_goto($specialty . '/ ' . $state);
}