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name

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name Punditsdkoslkdosdkoskdo

Convert HTML + CSS to PDF using PHP?

I have an HTML (not XHTML) document that renders fine in Firefox 3 and IE 7. It uses fairly basic CSS to style it and renders fine in HTML.

I'm now after a way of converting it to PDF. I have tried:

  • DOMPDF: it had huge problems with tables. I factored out my large nested tables and it helped (before it was just consuming up to 128M of memory then dying--thats my limit on memory in php.ini) but it makes a complete mess of tables and doesn't seem to get images. The tables were just basic stuff with some border styles to add some lines at various points;
  • HTML2PDF and HTML2PS: I actually had better luck with this. It rendered some of the images (all the images are Google Chart URLs) and the table formatting was much better but it seemed to have some complexity problem I haven't figured out yet and kept dying with unknown node_type() errors. Not sure where to go from here; and
  • Htmldoc: this seems to work fine on basic HTML but has almost no support for CSS whatsoever so you have to do everything in HTML (I didn't realize it was still 2001 in Htmldoc-land...) so it's useless to me.

I tried a Windows app called Html2Pdf Pilot that actually did a pretty decent job but I need something that at a minimum runs on Linux and ideally runs on-demand via PHP on the Webserver.

What am I missing, or how can I resolve this issue?

1) use MPDF !

a) extract in yourfolder

b) create file.php in yourfolder and insert such code:

<?php
include('../mpdf.php');
$mpdf=new mPDF();
$mpdf->WriteHTML('

Hallo World
Fisrt sentencee

'); $mpdf->Output(); exit; ?>

c) open file.php from your browser



 

2) Use pdfToHtml !

1) extract pdftohtml.exe to your root folder:

2) inside that folder, in anyfile.php file, put this code (assuming, there is a source example.pdf too):

<?php
$source="example.pdf";
$output_fold="FinalFolder";

    if (!file_exists($output_fold)) { mkdir($output_fold, 0777, true);}
$result= passthru("pdftohtml $source $output_fold/new_filename",$log);
//var_dump($result); var_dump($log);
?>

3) enter FinalFolder, and there will be the converted files (as many pages, as the source PDF had..)

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After some investigation and general hair-pulling the solution seems to be HTML2PDFDOMPDF did a terrible job with tables, borders and even moderately complex layout and htmldoc seems reasonably robust but is almost completely CSS-ignorant and I don't want to go back to doing HTML layout without CSS just for that program.

HTML2PDF looked the most promising but I kept having this weird error about null reference arguments to node_type. I finally found the solution to this. Basically, PHP 5.1.x worked fine with regex replaces (preg_replace_*) on strings of any size. PHP 5.2.1 introduced a php.ini config directive called pcre.backtrack_limit. What this config parameter does is limits the string length for which matching is done. Why this was introduced I don't know. The default value was chosen as 100,000. Why such a low value? Again, no idea.

bug was raised against PHP 5.2.1 for this, which is still open almost two years later.

What's horrifying about this is that when the limit is exceeded, the replace just silently fails. At least if an error had been raised and logged you'd have some indication of what happened, why and what to change to fix it. But no.

So I have a 70k HTML file to turn into PDF. It requires the following php.ini settings:

  • pcre.backtrack_limit = 2000000; # probably more than I need but that's OK
  • memory_limit = 1024M; # yes, one gigabyte; and
  • max_execution_time = 600; # yes, 10 minutes.

Now the astute reader may have noticed that my HTML file is smaller than 100k. The only reason I can guess as to why I hit this problem is that html2pdf does a conversion into xhtml as part of the process. Perhaps that took me over (although nearly 50% bloat seems odd). Whatever the case, the above worked.

Now, html2pdf is a resource hog. My 70k file takes approximately 5 minutes and at least 500-600M of RAM to create a 35 page PDF file. Not quick enough (by far) for a real-time download unfortunately and the memory usage puts the memory usage ratio in the order of 1000-to-1 (600M of RAM for a 70k file), which is utterly ridiculous.

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Important: Please note that this answer was written in 2009 and it might not be the most cost-effective solution today in 2019. Online alternatives are better today at this than they were back then.

Here are some online services that you can use:


Have a look at PrinceXML.

It's definitely the best HTML/CSS to PDF converter out there, although it's not free (But hey, your programming might not be free either, so if it saves you 10 hours of work, you're home free (since you also need to take into account that the alternative solutions will require you to setup a dedicated server with the right software)

Oh yeah, did I mention that this is the first (and probably only) HTML2PDF solution that does full ACID2 ?

PrinceXML Samples

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