Create a form
/**
* Implements hook_form().
*/
function MY_CUSTOM_FORM_form($node, &$form_state) {
$form = array();
$form['CUSTOM_FIELD'] = array(
'#type' => 'textfield',
'#label' => 'MY_LABEL',
);
$form['submit'] = array(
'#type' => 'submit',
'#value' => t('Submit')
)
return $form;
}
/**
* MY_CUSTOM_FORM validation handler.
*/
function MY_CUSTOM_FORM_form_validate($node, &$form_state) {
}
/**
* MY_CUSTOM_FORM submit handler.
*/
function MY_CUSTOM_FORM_form_submit($node, &$form_state) {
}
Call the form by using drupal_get_form. Form can be called inside blocks or pages as a single element or be a part of a build array.
If you're not sure how to use hook form, you can read the Write your first Drupal 7 module article.