FPDF Class and WordPress PDF upload - php

Question

I'm uisng FPDF for my PDF handling in my webshop. Whenever a user checks out I want to generate a PDF with all the data from the shopping cart and afterwards upload the PDF to the media library in WordPress.
I've tried a bunch of stuff now, but I haven't made anything yet that works. So far I can only save the PDF to a different folder by writing:
$pdf->Output($_SERVER['DOCUMENT_ROOT'].'/invoice/nameofinvoice.pdf', 'F');
My code looks like this:
if ( ! function_exists( 'wp_handle_upload' ) ) require_once( ABSPATH . 'wp-admin/includes/file.php' );
$uploadedfile = $pdf->Output('dimserPdf2014.pdf', 'F');
$upload_overrides = array( 'test_form' => false );
$movefile = wp_handle_upload( $uploadedfile, $upload_overrides );
// die(var_dump($movefile));
$wp_filetype = $movefile['type'];
$filename = $movefile['file'];
$wp_upload_dir = wp_upload_dir();
$attachment = array(
'guid' => $wp_upload_dir['url'] . '/' . basename( $filename ),
'post_mime_type' => $wp_filetype,
'post_title' => preg_replace('/\.[^.]+$/', '', basename($filename)),
'post_content' => '',
'post_status' => 'inherit'
);
// Id of attachment if needed
$attach_id = wp_insert_attachment( $attachment, $filename);
It does upload a file to the media library, but the file is empty, and if I uncomment the die > var_dump function I also get an array with simply nothing saying it's an empty file.
This is the script/class I'm using:
http://www.fpdf.org/
and the Output method accepts two parameters, filename and method of saving/downloading. As you can see here:
http://www.fpdf.org/en/doc/output.htm and I've tried every single parameter so far with no luck.
Any idea on why WordPress uploads an empty file and not my PDF?

Answer 1

I've been doing some work with mPDF, which is a (better documented & maintained imho) fork of FPDF. From what I can see in the documentation, the Output method doesn't return anything unless you pass the "S" dest.
Also, according to the Codex the file in wp_handle_upload is for working on one item in the $_FILES superglobal. You shouldn't need it in your case if you generate your PDF in the uploads directory.
Try this instead:
if ( ! function_exists ... ;
$wp_upload_dir = wp_upload_dir();
$uploadedfile = trailingslashit ( $wp_upload_dir['path'] ) . 'dimserPdf2014.pdf';
$pdf->Output($uploadedfile, 'F');
$attachment = array(
'guid' => trailingslashit ($wp_upload_dir['url']) . basename( $uploadedfile ),
'post_mime_type' => 'application/pdf',
'post_title' => preg_replace('/\.[^.]+$/', '', basename($filename)),
'post_content' => '',
'post_status' => 'inherit'
);
// Id of attachment if needed
$attach_id = wp_insert_attachment( $attachment, $uploadedfile);