Change text fields to support wysiwyg editors & text formats.

Thanks for the good tip, rupertj.
I can successfully change the field to text_format and specify the format. The wysiwyg editor appears!

I used this code:

function mymodule_form_alter(&$form, $form_state, $form_id) {
  $id = $form['#id'];
  switch ($id) {
  case 'locationmap-admin-settings':
     $form['info']['locationmap_body']['#type'] = 'text_format';
     $form['info']['locationmap_body']['#format'] = 'full_html';
    break;
  }
}

Then I type some text in the editor and save it. Unfortunately this raises an error without displaying the text I typed:

Error message
Warning: htmlspecialchars() expects parameter 1 to be string, array given in check_plain() (line 1572 of /var/www/switch/drupal7/includes/bootstrap.inc).

Suggestions are welcome. :)

Well, you don't have to if you don't want, but a working workaround for people who want it, would be nice.
Right now we are stuck with this error when trying to alter the field type and try to save some text in the editor.
Any help is appreciated.

Thanks babbage, much appreciated!
In the mean time, I have found a solution to get rid of the error. But your patch will be better, because my fix won't work with plain textareas. But I'm quite proud that I found it , so here goes.

The code to alter the form field to text_format:

function hook_form_alter(&$form, $form_state, $form_id) {
  $id = $form['#id'];
  switch ($id) {
    case 'locationmap-admin-settings':
      $locationmap_body = variable_get('locationmap_body');
      $locationmap_body_value = $locationmap_body['value'];
      $form['info']['locationmap_body']['#type'] = 'text_format';
      $form['info']['locationmap_body']['#default_value'] = $locationmap_body_value;
      break;
  }
}

Then I changed the line in locationmap.module:

$output = '<div id="locationmap_body">' . $locationmap_body . '</div>';

To:

$output = '<div id="locationmap_body">' . $locationmap_body['value'] . '</div>';

The text_format element outputs an array with 2 elements, one is the value of the field, the other is the text format. So the module has to print the value element of the array, not the entire array.
The difference with plain textarea is that textarea only outputs a string containing the value. I hope I'm right.

But I'm eager to see your patch, babbage. :)
Thanks again!

That's really great, babbage!
Forget the ugliness a little, that's not what the user sees (normally).
Really thanks for the quick update. :)

I promise to review it tonight. Haven't had the time to apply the patch, but will review everything tonight.
Thanks!

Hey babbage,

I disabled 7.x-2.1, deleted the whole module folder, installed 7.x-2.x-dev and enabled it.
When going to admin/config/locationmap, I get following drupal error message:

    Notice: Uninitialized string offset: 0 in locationmap_admin_settings() (line 177 of /var/www/switch/drupal7/sites/all/modules/contrib/locationmap/locationmap.module).
    Notice: Uninitialized string offset: 0 in locationmap_admin_settings() (line 178 of /var/www/switch/drupal7/sites/all/modules/contrib/locationmap/locationmap.module).

For the rest, everything works. Map is showing and I can use my favorite CKEditor in the config page. :)
One little thing: when going to admin/config/locationmap, I was only interested in the info above the map. So I selected Full html there. The other info boxes were not important to me, so I left them alone. However, when trying to save the settings, I got the error that I have to select a text format for every item/text field.
Not that it's fatal, but it's a bit annoying. ;)

Thanks!

Joost

Mmm, today I'm not getting the error (the one I put in a code box in the previous post) anymore... that's strange.
But I think it had something to do with the fact that the footer field was the only empty one.
Marker and 'above info' had some text.

Great job on the ugliness fix, babbage. Looks really smooth now!

Allrighty.
I disabled the previous version, enabled the new dev version, ran update.php and went to my locationmap.
All is well. And for the record: no error messages. ;-)

I think this issue can be closed. Job well done, babbage! Much appreciated.
I'll send you a link when my website is live. :)