Printer Sample App

This app is (almost) the simplest possible Printer application. You should be able to use it to quickly get started building your own, much more interested application.

This app is designed to demonstrate automated scheduling of content for printers, as opposed to the human-driven mail and paint apps. People who register their printers with an application like this will have content delivered to their printer automatically on a regular basis.

You can take a look at the source.

If you don’t have a printer, why not find out how to get or make a printer for yourself?

How it works

All this happens automatically without user intervention, so in this way “publications” can be scheduled to appear at any time.

‘Registrations’ are created by storing a print URL alongside any other relevant information.

The rake run task is scheduled (in this case by Heroku, but possibly by cron or anything else) to run at 8 am. At this time, it will send a request for each job to its corresponding print URL, with the url parameter set to a unique job URL in this app.

The printer backend server takes this page and rasterises it for the destination printer to download.

Deploying to Heroku

First, create the heroku app:

heroku apps:create <app name>

Then, we'll need a few addons

heroku addons:add heroku-postgresql
heroku addons:add scheduler:standard

Next, set up the scheduler

heroku addons:open scheduler

You'll want to add a rake run task to run probably once a day, whenever is appropriate to send the data to the printer(s).

We need to set some configuration for the task. In this case, it's to tell the scheduler what the URL for our application is. Don't forget to change <app name> to whatever you chose above!

heroku config:set APP_URL="http://<app name>.herokuapp.com"

Finally, deploy the actual application

git push heroku master

Once everything starts running, you should be able to visit your application at the URL heroku reports (probably http://.herokuapp.com) and start registering printer(s).

More information

To find out more, you can take a look at any (or all) of the following:

• The introductory blog post;
• The project page;
• The backend server we are running;
• The source for this app, the mail app, the paint app or the backend server itself.