使用PHP将HTML / CSS转换为PDF时出错

Question

I build bar codes using jquery in a div in my web app. The black bars are contructed as a set of div tags with their background as black or white as follows,

<div style='padding: 0px; overflow: auto; width: 194px;' id='bar1'>
  <div style='float: left; font-size: 0px; background-color: #FFFFFF; height: 40px; width: 60px'>
  <div style='float: left; font-size: 0px; width:0; border-left: 2px solid #000000; height: 40px;'>

I have tried multiple PHP packages (htmp2pdf, dompdf, tcpdf) to convert this to PDF but come up with either a blank PDF or an error as it sees nested div in the content. Can anyone tell me how can I convert these generated barcodes to PDF suing PHP?

Answer 1

Try wkhtmltopdf which is a simple shell utility to convert html to pdf using the webkit rendering engine.

To use it, unpack it and run it like this:

> wkhtmltopdf www.mydomain.com/barcode3 barcode3.pdf

Basically, it will run over n HTML pages and generate PDF's without the overhead of purely dynamic PDF generation!

This might offer you a solution, but you'll need to check the requirements and see if it fits with your server constraints. It worked really well when we used it for producing accurate reports directly from HTML.

EDIT: EG, running it as a potential user function from within PHP:

For Linux:

exec("wkhtmltopdf http://mydomain.com /home/user/$user.barcode3.pdf 2>&1");

For Windows:

<?php
exec('C://path/to/package//wkhtmltopdf http://mydomain.html barcode3.pdf');

echo "PDF Created Successfully";
?>

Answer 2

Would it help if you used <img> data instead of drawing the bars with <div> rectangles? Not sure if you need Code 128 or another symbology, but there is a complete set of inline (base64) Code 128 images at http://notionovus.com/blog/code-128-barcode/ .

I initially tried to generate barcodes by drawing rectangles, but found that letting the browser do the scaling saved me a lot of work. Sounds like the <div> tags have their down side as well.