How to dump $form_state in hook form_submit?

Hi Giorgio,
Yesterday I spent a whole saturday afternoon trying to understand how to create a page that would take input from a form and just display it.

<?php
echo $_POST['name];
?>

A trivial piece of PHP code, yet not trivial in Drupal.

The answer is that if you don't process your data in hook_form_submit OR you include a redirect, the form will just be displayed again and your data will be lost.

This is how I solved it - I don't know if this is the best solution, but it worked for me...

I include the whole module named "ws". I use a block to display the form and a page to show the result.

<?php
// $Id$

/**
 * @file
 * Simple form test
 */

/**
 * Implementation of hook_block
 */
function ws_block($op='list' , $delta=0, $edit=array()) {
  switch ($op) {
    case 'view':
      $blocks['content'] = drupal_get_form('ws_form');
      return $blocks;
  }
}

/** 
 *Show form
 */

function ws_form($form_state) {
    $form['name'] = array (
        '#type' => 'textfield',
        '#title' => 'Name',
    );

    $form['submit'] = array (
        '#type' => 'submit',
        '#value' => 'Send',
    );
return $form;
}

/**
 * Here the form is processed, the variable "name" is sent as a parameter to the ws function

function ws_form_submit($form, &$form_state) {
    $form_state['redirect'] = array('ws','name='.$form_state['values']['name']); //IMPORTANT!!
    return;
}
/**
 * Implementation of hook_menu
*/

function ws_menu() {
    $items['ws'] = array (
        'page callback' => 'show_name',
        'access callback' => TRUE,
        'type' =>  MENU_CALLBACK,
        );
return $items;
}

/**
 * This function gets the parameter and shows it
*/

function show_name($name) {
return 'Hello '.$name;
}

That's it! After you enter your name, say 'John', and submit the form, you are redirected to q=ws/John, which reads Hello John.

It doesn't work to put output in the form submit, unless the submit fails.

THIS IS VERY LATE, BUT MAY BE USEFULL TO OTHERS WHO HAVE THE SAME QUESTION

I haven't checked Clau's response much, but I would like to offer some advice, on how I do this.

First: most likely your form submit is happening, and content is being written to the screen, however as Clau suggested, the page is then being redirected back to the form. This is the expected behaviour with form submits using the form system.

Ok, so now I can think of a couple of debugging situations in which you'd want to print_r the form_state, so I'll respond as though this is the case.
The simplest solution is to simple add a die after the print_r. This means that your app will stop after your debugging code has been executed.

function my_form_submit($form,$form_state) {
  print_r($form_state);
  die("\n<br/>DIE");
}

Here you should get a white screen with your print_r output on the page.

If you need to keep the redirect, or are planning on outputting something more asethetic to be used in the actualy application, then consider using the drupal_set_message function. Drupal_set_message will place the output into session space, where it will be pulled on the next valid page load, and placed in the messages section of the page template. This only works if you haven't disabled Drupal messages, either by configuration, or by removing the template variable from your theme.

function my_form_submit($form.$form_state) {
  drupal_set_message( 'Here are the form contents:' . var_export($form_state , true) );
}

You'll likely want something prettier than what I've put.