Introducing POSGuys Barcode API V.0.1
By: Siva Katir - 4/11/2014

<p>Today we're excited to announce the availability of our barcode image API. This is the system that we use to back our online <a href="https://posguys.com/barcode">barcode generator</a>.</p>
<p>Read on for a quick look at how to get started using our Image and Image path APIs!</p>
<p><br /></p>
<h2>Image Path</h2>
<p>The Barcode Image Path API will generate the requested barcode and send back a string that is the URL of the image. This is useful for pre-generating an image so that you can download it or link to it repeatedly.</p>
<p><br /></p>
<h3>Basic Ussage</h3>
<pre><code>https://posguys.com/Api/GenerateBarcodeLink/?content=test&height=200&width=200&hideText=true&symbology=QR_CODE

return: https://posguys.com/Api/BarcodeImage/44EAB645783128354826641F74DF2CE4
</code></pre>

<p><strong>Paramaters:</strong></p>
<ul>
<li>content: A URL Encoded string to be barcoded</li>
<li>height: Image height in pixels</li>
<li>width: Image width in pixels</li>
<li>hideText: (boolean: true/false) Do not display content string in image</li>
<li>symbology: See list of string values in the table below.</li>
</ul>
<p><strong>Example:</strong></p>
<pre><code>https://posguys.com/Api/GenerateBarcodeLink/?content=http%3a%2f%2fwww.posguys.com%2fbarcode-scanner_3%2fHoneywell-Voyager-1200g_1050%2f&height=200&width=200&hideText=true&symbology=QR_CODE

return: https://posguys.com/Api/BarcodeImage/F1535116E57BAF2C7D80CC8719739750
</code></pre>

<p><br /></p>
<h2>Image</h2>
<p>The Image API will return an <code>image/png</code> image directly, this is useful for putting the <code>GET</code> request as the <code>src</code> tag in an <code><img /></code>.</p>
<p><br /></p>
<h3>Basic Usage</h3>
<pre><code>https://posguys.com/Api/GenerateBarcodeImage/?content=http%3a%2f%2fwww.posguys.com%2fbarcode-reader-scanner_3%2fHoneywell-Voyager-1200g_1050%2f&height=200&width=200&hideText=true&symbology=QR_CODE

<h3>Result:</h3>
<img src="https://posguys.com/Api/GenerateBarcodeImage/?content=http%3a%2f%2fwww.posguys.com%2fbarcode-reader-scanner_3%2fHoneywell-Voyager-1200g_1050%2f&height=200&width=200&hideText=true&symbology=QR_CODE" width="200" height="200" />
<p><br /></p>
<h2>Supported Symbologies</h2>
<table>
<thead>
<tr>
	<th>Symbology Name</th>
	<th align="left">Request Value</th>
</tr>
</thead>
<tbody>
<tr>
	<td>Aztec</td>
	<td align="left">AZTEC</td>
</tr>
<tr>
	<td>CODABAR</td>
	<td align="left">CODABAR</td>
</tr>
<tr>
	<td>Code 128</td>
	<td align="left">CODE_128</td>
</tr>
<tr>
	<td>Code 39</td>
	<td align="left">CODE_39</td>
</tr>
<tr>
	<td>Data Matrix</td>
	<td align="left">DATA_MATRIX</td>
</tr>
<tr>
	<td>EAN 13</td>
	<td align="left">EAN_13</td>
</tr>
<tr>
	<td>EAN 8</td>
	<td align="left">EAN_8</td>
</tr>
<tr>
	<td>ITF</td>
	<td align="left">ITF</td>
</tr>
<tr>
	<td>MSI</td>
	<td align="left">MSI</td>
</tr>
<tr>
	<td>PDF 417</td>
	<td align="left">PDF_417</td>
</tr>
<tr>
	<td>Plessey</td>
	<td align="left">PLESSEY</td>
</tr>
<tr>
	<td>QR Code</td>
	<td align="left">QR_CODE</td>
</tr>
<tr>
	<td>UPC A</td>
	<td align="left">UPC_A</td>
</tr>
</tbody>
</table>
<p><br /></p>
<h2>FAQ</h2>
<h3>Why would I use this type of system over say a  barcode font?</h3>
<p>POSGuys often needs to place barcodes in places that may or may not have a barcode font available. If you need to include a barcode in an email message sending it using the font will fail for most users. Displaying a barcode on a website is equally problematic. If a user doesn't have that specific font installed they won't see the barcode. </p>
<p>Even if a user has a barcode font they may not have the right font. Or in the case of QR codes and PDF rendering via a font is simply not feasible (It is technically possible if you're happy to mess with line heights and kerning a bunch).</p>
<h3>Is this safe for production?</h3>
<p>We use it in production so we think so. This is a true dogfooding API: we use it. We don't use another version, or have a special set a parameters. What is documented above is what we use. It runs on top of our website which is a regionally distributed and load balanced system in multiple data centers. </p>
<h3>Attribution</h3>
<p>While it's always nice to be recognized for your work there are no requirements for attribution of these images. </p>
<p><br /></p>
<h2>Caveats</h2>
<p><strong>Errors:</strong></p>
<p>In the event that a barcode cannot be generated only the <code>GenerateBarcodeLink</code> will tell you why. <code>GenerateBarcodeImage</code> will return an empty response currently. We are currently working on fixing this shortcoming so that both will return a string with the message. </p>
<p>The most common reason for failures are:</p>
<ul>
<li>Invalid Symbology - The symbology string could not be parsed into a valid format.</li>
<li>Invalid barcode content - Some barcodes have limitations on the characters that they support. Including unsupported characters will result in an error.</li>
</ul>
<p><strong>Speed:</strong></p>
<p>For the sake of our sanity we do not store the barcode images. This means that for every request the image is re-generated unless it's been requested recently (there is a short cache period). This does mean that there is a slight performance hit every time an image is requested, because of this it's best to set the <code>width</code> and <code>height</code> attributes in the <code><img /></code> tag so that when the image does load it doesn't cause a re-flowing of the content.</p>
<p><br /></p>
<h2>Enjoy!</h2>
<p><strong>-POSGuys Operations</strong></p>

Introducing POSGuys Barcode API V.0.1 By: Siva Katir - 4/11/2014

Recent Posts By Siva Katir

Introducing POSGuys Barcode API V.0.1
By: Siva Katir - 4/11/2014