A barebones Sinatra app for generating barcodes.
$ docker run --rm -p 4567:4567 rlue/nelson-scandela # or raw-dog it $ git clone https://github.com/rlue/nelson-scandela $ cd nelson-scandela $ bundle install $ ruby app.rb
Then, visit http://localhost:4567/xxx, where
xxx is the string you wish to
In Taiwan (where I live), many commercial services can be purchased online and paid for in person at a convenience store by presenting a vendor-supplied barcode to the cashier.
Some of these barcodes are provided to the consumer via mobile apps. If you wish to avoid installing unnecessary software on your phone and know the content of your desired barcode, you can use this web app to generate the barcode instead.
Of course, many existing web apps do just this, but the ones I’ve found work via an HTML form and POST request, meaning generated barcodes cannot be bookmarked for future use. In contrast, this app uses a URL parameter and GET request.
Caveat: Why don’t other apps use GET endpoints?
Search engines build their indices using so-called spiders to “crawl the web”. This is one example of many different kinds of bots that, depending on which source you consult, account for 20–50% of all traffic on the Internet.
Spiders work by recursively following every link they find; i.e., by finding and visiting GET endpoints. This means that if you deploy this application and someone places a link to it on their website or a forum, your application will end up serving some non-human traffic.
At least, I think that’s why other apps use POST endpoints.