TYPO3 Extension: Generate a PDF - typo3

Question

Im trying to make an extension with Kickstarter that overrides the normal rendering of the page, and renders a PDF file. For this im using FPDF. But im not sure how to do it. I tried doing this, but it didnt work:
<?php
// require_once(PATH_tslib . 'class.tslib_pibase.php');
class tx_ishurkunde_pi1 extends tslib_pibase {
public $prefixId = 'tx_ishurkunde_pi1';
public $scriptRelPath = 'pi1/class.tx_ishurkunde_pi1.php';
public $extKey = 'ish_urkunde';
public $pi_checkCHash = TRUE;
public function main($content, array $conf) {
if (!t3lib_extMgm::isLoaded('fpdf')) return "Error!";
$pdf = new FPDF();
$pdf->AddPage();
$content = $pdf->Output('', 'S');
return $content;
}
}
?>
It still keeps rendering the normal web template. What am I missing?
FYI, Im not trying to render the HTML as PDF. Im trying to generate a PDF from scratch, using the URL parameters are text variables.

Answer 1

As far as I understood, your aim is to render a PDF instead of page elements.
Your current approach will not work since you are inserting a plugin onto the page. The plugin's return value is then given back to the TYPO3 content parser, and if the page has finished parsing, it is displayed. There is no part in it where you can throw over the whole page rendering; At least it is not intended to do, and you shouldn't to (albeit there are extensions that do this).
The eID approach would be to either create an eID script (have a look at dd_googlesitemap) which is called via GET param and renders only what you need. There you basically can do everything you want to.
In your extension's ext_localconf.php you register the eID script, like this:
$GLOBALS['TYPO3_CONF_VARS']['FE']['eID_include'][$_EXTKEY] = "EXT:{$_EXTKEY}/path/to/my/EIDHandler.php";
An Example eID handler structure:
class Tx_MyExt_EIDHandler
{
public function main()
{
// Your code here
}
}
$output = t3lib_div::makeInstance('Tx_MyExt_EIDHandler');
$output->main();
To call your eID script in the frontend, you append the appropriate GET params, like http://example.com/index.php?eID=tx_myext. This is the array key you defined in your ext_localconf.php (in my example, it is $_EXTKEY, but it can basically be any string).
The plugin/typoscript approach would be like e.g. TemplaVoila does it: You create a PAGE type and call a user_func which does your things. This would be the fastest approach because you already have a plugin. Important is that you render your own page type with only your plugin in it.
Example TypoScript:
specialPage = PAGE
specialPage {
type = 2
10 = USER
10.userFunc = tx_myextension_pi1->myFunc
}
After that, you can call your new page with http://example.com/index.php?type=2. However, headers etc are still rendered and you may need to remove them.