Parsing contao / typolight codes in templates for pdf output

Question

I wrote a script which exports an contao-catalog item as PDF if the user saves the entry in the backend-view.

my problem is, that in the templates there are codes like this, if I print out i.e. the variable $entry['data']['link_img']['ref'].:

a:3:{i:0;s:2:"14";i:1;s:2:"15";i:2;s:2:"13";} (a serialized Array, which does not match the foreach specifications)

The php code looks like this:

<?php foreach ($entry['data']['link_img']['ref'] as $link_img):?>
    <? print($link_img); ?>
        <a href="werke-detail/items/<?php echo $link_img['alias']; ?>.html">
    <?php echo $link_img['title']; ?> </a><br />
<?php endforeach; ?>

when contao parses the template, this works, if I get the data, it doesn't. Is there a function from contao which I can use, to decode this, to get my foreach to work?

UPDATE

The big question is: Where does Contao do it's magic in the template-engine and how can I do the same?

Thanks

Answer 1

To extend on the comment given by Pekka. Contao stores certain data types as a serialized PHP array.

Usually within the Backend any field that is stored as follows:

$GLOBALS['TL_DCA']['tl_dca']['fields']['yourfield']['eval']['multiple'] = true;

Will store that data as serialized, some built in classes such as User will unserialize such data, ie if you're using $this->User .

Also, note that all serialized arrays are stored in BLOB types in the database, so database.sql for a given module can give you clues about if something will be in that format.

The serialize/unserialize functions are stored in system/functions.php which contains some other useful PHP functions.