Print QR Codes For Easy URL References

Often regarded as an advertising eyesore, QR codes have their place in certain circumstances. One obvious example is providing an easily-scanned sigil on a printed Web page that enables the user to return to the live version without having to type the URL.

Web page printed with a self-referential QR code

To create the matching QR code, we’ll use Google’s Chart API, which has four required components:

The kind of chart information we want Google to deliver (qr, in our case);

The rendered size of the QR sigil, in pixels;

The URL to encode;

The form of character encoding to use.

We’d typically associate the URL with a heading element at the top of the page:

Code language: HTML

<header>
<h1>Lizabeth’s Salon</h1>
<h2>Providing Intellectual Stimulation Online Since 2001</h1>
</header>

To create the printed result, we’ll provide a margin on the right side of the h1 that is large enough for the heading, and then position a QR code in that area:

Code language: CSS

header h1 {
   margin-right: 200px;
   margin-bottom: 2rem;
   line-height: 1.5;
}

Because the QR code will be unique to each page, this would be added as an embedded style sheet:

Code language: CSS

@media print {
   header h1:after {
      content: url(https://chart.googleapis.com/chart?cht=qr&chs=150x150&chl=http://yourdomain.com&choe=UTF-8);
      position: absolute;
      right: 0;
      top: 0;
   }
}

This approach has the downside of forcing the developer to enter a URL individually for each page into the API code. If your Web host is running PHP, you can provide the URL of the current page automatically:

Code language: CSS

@media print {
   h1:after {
      content: url(https://chart.googleapis.com/chart?cht=qr&chs=150x150
&chl=http://<?=$_SERVER["SERVER_NAME"].$_SERVER["REQUEST_URI"];?>
&choe=UTF-8);
      position: absolute;
      right: 0;
      top: 0;
   }
}

Source link

Tips And Tricks For Print Style Sheets – Smashing Magazine