PHPMaster.com has an interesting new article posted today showing how you can use PHP to create a two-way messaging (SMS) application that can both send and initiate actions based on message content.

SMS is used for various purposes these days. For example, major websites like Gmail and Facebook use SMS to improve their authentication process with multi-factor authentication and notifying users about the updates. These are one-way SMS applications since messages are sent only from these sites to the user. Two-way SMS applications are more complex than one-way ones. In two-way SMS apps, a user can initiate a conversation by sending messages, and then the application responds according to the user’s commands.

They base the application on the Clickatell SMS service (not free, but cheap - pay by the message too) which includes the ability to hook into your API on a specific endpoint and relay the message data. The message can either be sent via a POST or GET and can easily be interpreted in your app extracting things like a timestamp, the number it came from and, of course, the actual text of the message. There's also a section about the "User Data Header" functionality that lets you easily split up a message for recombination on the remote device. Code is included for all examples.

Henri Bergius has a new post to his blog today sharing details about a messaging protocol that can help PHP and Node.js play together nicely - DNode.

Both environments have their strong points. Node.js is very fast and flexible, but PHP has a lot more mature tools and libraries available. So in a lot of projects it is hard to choose between the two. But now you might not have to. DNode is a remote method invocation protocol originally written for Node.js, as the name probably tells. But as the protocol itself is quite simple, just sending newline-terminated JSON packets over TCP connections, implementations have started popping up in other languages. You can talk DNode in Ruby, Perl, Python, Java, and now PHP.

He includes a quick example of both sides of the messaging - a simple server on the Node.js side that looks for a DNode request and using the dnode PHP client to connect to it (and return the input number multiplied by 100). He also includes a method that allows for bidirectional communication with a service that converts from Celsius to Fahrenheit.