FPDF is Freeware (it is stated at the beginning of the source file). There is no usage restriction. You may embed it freely in your application (commercial or not), with or without modification.
2. When I try to create a PDF, a lot of weird characters show on the screen. Why?These "weird" characters are in fact the actual content of your PDF. This behaviour is a bug of
IE. When it first receives an HTML page, then a PDF from the same URL, it displays it directly
without launching Acrobat. This happens frequently during the development stage: on the least
script error, an HTML page is sent, and after correction, the PDF arrives.
To solve the problem, simply quit and restart IE. You can also go to another URL and come
back.
To avoid this kind of inconvenience during the development, you can generate the PDF directly
to a file and open it through the explorer.
First of all, check that you send nothing to the browser after the PDF (not even a space or a
carriage return). You can put an exit statement just after the call to the Output() method to
be sure.
If it still doesn't work, it means you're a victim of the "blank page syndrome". IE used in
conjunction with the Acrobat plug-in suffers from numerous bugs, in all versions. You should
test your application with as many IE versions as possible (at least if you're on the Internet).
The problem occurs mostly with the POST method, so it is strongly advised to avoid it (all the
more that it causes other problems, see the next question). The GET works better but may fail
when the URL becomes too long: don't use a query string with more than 45 characters. However, a
tip exists to exceed this limit: end the URL with .pdf, which tricks IE. If you use a
formular, you can add a hidden field at the last position:
| <INPUT TYPE="HIDDEN" NAME="ext" VALUE=".pdf"> |
|
//Determine a temporary file name in the current directory $file=basename(tempnam(getcwd(),'tmp')); //Save PDF to file $pdf->Output($file); //JavaScript redirection echo "<HTML><SCRIPT>document.location='getpdf.php?f=$file';</SCRIPT></HTML>"; |
|
<?php $f=$HTTP_GET_VARS['f']; //Check file (don't skip it!) if(substr($f,0,3)!='tmp' or strpos($f,'/') or strpos($f,'\\')) die('Incorrect file name'); if(!file_exists($f)) die('File does not exist'); //Handle special IE request if needed if($HTTP_ENV_VARS['USER_AGENT']=='contype') { Header('Content-Type: application/pdf'); exit; } //Output PDF Header('Content-Type: application/pdf'); Header('Content-Length: '.filesize($f)); readfile($f); //Remove file unlink($f); exit; ?> |
|
//Determine a temporary file name in the current directory $file=basename(tempnam(getcwd(),'tmp')); rename($file,$file.'.pdf'); $file.='.pdf'; //Save PDF to file $pdf->Output($file); //JavaScript redirection echo "<HTML><SCRIPT>document.location='$file';</SCRIPT></HTML>"; |
|
function CleanFiles($dir) { //Delete temporary files $t=time(); $h=opendir($dir); while($file=readdir($h)) { if(substr($file,0,3)=='tmp' and substr($file,-4)=='.pdf') { $path=$dir.'/'.$file; if($t-filemtime($path)>3600) @unlink($path); } } closedir($h); } |
It's a problem affecting some versions of IE (especially the first 5.5). See the previous question for the ways to work around it.
5. When I use a PHP session, IE doesn't display my PDF any more but asks me to download it.It's a problem affecting some versions of IE. To work around it, add the following line before
session_start():
| session_cache_limiter('private'); |
The problem may be fixed by adding this line:
| Header('Pragma: public'); |
When the decimal separator is configured as a comma before including a file, there is a bug in PHP and decimal numbers get truncated. Therefore you shouldn't make a call to setlocale() before including the class. On Unix, you shouldn't set the LC_ALL environment variable neither, for it is equivalent to a setlocale() call.
8. I try to put a PNG and Acrobat says "There was an error processing a page. A drawing error occurred".Acrobat 5 has a bug and is unable to display transparent monochrome images (i.e. with 1 bit per pixel). Remove transparency or save your image in 16 colors (4 bits per pixel) or more.
9. I try to put an image and Acrobat says "There was an error processing a page. Wrong operand type".You have to give at least one dimension; height and width can't be both equal to zero.
10. I'd like to put my image in real size in the PDF. How can I convert pixels to mm?An image has no "real size". The dimension it is given in the document is arbitrary. Except if you want to impose a particular resolution (for instance 72dpi, which is the one typically used on screen display), in which case the ratio between the pixel width and the resolution gives the dimension.
11. I encounter the following error when I try to generate a PDF: Warning: Cannot add header information - headers already sent by (output started at script.php:X)You must send nothing to the browser except the PDF itself: no HTML, no space, no carriage return, neither before nor after. The script outputs something at line X.
12. I try to display a variable in the Header method but nothing prints.You have to use the global keyword, for instance:
|
function Header() { global $title; $this->SetFont('Arial','B',15); $this->Cell(0,10,$title,1,1,'C'); } |
You have to create an object from the PDF class, not FPDF:
| $pdf=new PDF(); |
You have to enclose your string with double quotes, not single ones.
15. I try to put the euro symbol but it doesn't work.The standard fonts have the euro character at position 128. You can define a constant like this
for convenience:
| define('EURO',chr(128)); |
To respect dimensions, you have to uncheck the option "Fit to page" in the print dialog box.
17. I'd like to use the whole surface of the page, but when printed I always have some margins. How can I get rid of them?All printers have physical margins (different depending on the model), it is therefore impossible to remove them and print on the totality of the paper.
18. What's the limit of the file sizes I can generate with FPDF?There is no particular limit. There are some constraints however:
- The maximum memory size allocated to PHP scripts defaults to 8MB. For very big documents,
especially with images, this limit may be reached (the file being built into memory). The
parameter is configured in the php.ini file.
- The maximum execution time allocated defaults to 30 seconds. This limit can of course be easily
reached. It is configured in php.ini and may be altered dynamically with set_time_limit().
- Browsers generally have a 5 minute time-out. If you send the PDF directly to the browser and
reach the limit, it will be lost. It is therefore advised for very big documents to
generate them in a file, and to send some data to the browser from time to time (for instance
page 1, page 2... with flush() to force the output). When the document is finished, you can send
a redirection on it with JavaScript or create a link.
Remark: even when the browser goes in time-out, the script may continue to run on the server.
No.
20. I'd like to make a search engine in PHP and index PDF files. Can I do it with FPDF?No. But a GPL C utility does exist, pdftotext, which is able to extract the textual content from
a PDF. It is provided with the Xpdf package:
http://www.foolabs.com/xpdf/
No. But a GPL C utility does exist, htmldoc, which allows to do it and gives good results:
http://www.easysw.com/htmldoc/
No. But a free C utility exists to perform this task:
http://thierry.schmit.free.fr/dev/mbtPdfAsm/enMbtPdfAsm2.html
You can't for the moment. The feature will be implemented in the future.