Getting started with PHP

In this recipe we will use Crossbar.io to generate an application template for a WAMP application written in PHP using Thruway, an open-source WAMP implementation for PHP. The generated application includes a JavaScript frontend to run in a browser.

The frontend and backend components will talk with each other using all four main interactions available in WAMP:

1. call a remote procedure
2. register a procedure for remote calling
3. publish an event to a topic
4. subscribe to a topic to receive events

We will run the whole application with Crossbar.io serving as a WAMP router, static Web server and PHP/Thruway application component host.

Prerequisites

Install PHP and Composer:

sudo apt-get install -y php5-cli php5-json curl
curl -s http://getcomposer.org/installer | php
sudo mv composer.phar /usr/local/bin/composer

Create an example application

To create a new Crossbar.io node and generate a PHP / Thruway based "Hello world!" example application:

crossbar init --template hello:php --appdir $HOME/hello

This will initialize a new node and application under $HOME/hello using the application template hello:php.

To get a list of available templates, use crossbar templates.

You should see the application template being initialized:

oberstet@ubuntu1404:~$ crossbar init --template hello:php --appdir $HOME/hello
Crossbar.io application directory '/home/oberstet/hello' created
Initializing application template 'hello:php' in directory '/home/oberstet/hello'
Creating directory /home/oberstet/hello/.crossbar
Creating directory /home/oberstet/hello/web
Creating file      /home/oberstet/hello/README.md
Creating file      /home/oberstet/hello/client.php
Creating file      /home/oberstet/hello/Makefile
Creating file      /home/oberstet/hello/.gitignore
Creating file      /home/oberstet/hello/.crossbar/config.json
Creating file      /home/oberstet/hello/web/index.html
Creating file      /home/oberstet/hello/web/autobahn.min.js
Application template initialized

Now install dependencies for the PHP/Thruway client by entering 'make install', start Crossbar using 'crossbar start' and open http://localhost:8080 in your browser.

Install example dependencies

The dependencies for the PHP example need to be installed (once):

cd $HOME/hello
make install

Start the node

Start your new Crossbar.io node using:

cd $HOME/hello
crossbar start

You should see the node starting:

oberstet@ubuntu1404:~/hello$ crossbar start
2014-06-25 15:34:23+0200 [Controller  28900] Log opened.
2014-06-25 15:34:23+0200 [Controller  28900] ============================== Crossbar.io ==============================

2014-06-25 15:34:23+0200 [Controller  28900] Crossbar.io 0.9.6 starting
2014-06-25 15:34:23+0200 [Controller  28900] Running on CPython using EPollReactor reactor
2014-06-25 15:34:23+0200 [Controller  28900] Starting from node directory /home/oberstet/hello/.crossbar
2014-06-25 15:34:23+0200 [Controller  28900] Starting from local configuration '/home/oberstet/hello/.crossbar/config.json'
2014-06-25 15:34:23+0200 [Controller  28900] No WAMPlets detected in enviroment.
2014-06-25 15:34:23+0200 [Controller  28900] Starting Router with ID 'worker1' ..
2014-06-25 15:34:23+0200 [Router      28909] Log opened.
2014-06-25 15:34:24+0200 [Router      28909] Running under CPython using EPollReactor reactor
2014-06-25 15:34:24+0200 [Router      28909] Entering event loop ..
2014-06-25 15:34:24+0200 [Controller  28900] Router with ID 'worker1' and PID 28909 started
2014-06-25 15:34:24+0200 [Router      28909] Monkey-patched MIME table (0 of 551 entries)
2014-06-25 15:34:24+0200 [Router      28909] Site starting on 8080
2014-06-25 15:34:24+0200 [Controller  28900] Router 'worker1': transport 'transport1' started
2014-06-25 15:34:24+0200 [Controller  28900] Starting Guest with ID 'worker2' ..
2014-06-25 15:34:24+0200 [Controller  28900] GuestWorkerClientProtocol.connectionMade
2014-06-25 15:34:24+0200 [Controller  28900] Guest with ID 'worker2' and PID 28912 started
2014-06-25 15:34:24+0200 [Controller  28900] Guest 'worker2': started
2014-06-25 15:34:24+0200 [Guest       28912] Starting Transport
2014-06-25 15:34:24+0200 [Guest       28912] Pawl has connected
2014-06-25 15:34:24+0200 [Guest       28912] Received: [2,440447902995220,{"authrole":"anonymous","authmethod":"anonymous","authprovider":"anonymous","roles":{"broker":{"features":{"publisher_identification":true,"publisher_exclusion":true,"subscriber_blackwhite_listing":true}},"dealer":{"features":{"progressive_call_results":true,"caller_identification":true}}},"authid":"anonymous"}]
2014-06-25 15:34:24+0200 [Guest       28912] Received: [33,1471889554668967,8790061651978363]
2014-06-25 15:34:24+0200 [Guest       28912] Received: [17,1471889554670221,2585505197144630]
2014-06-25 15:34:24+0200 [Guest       28912] Publish Acknowledged!
2014-06-25 15:34:24+0200 [Guest       28912] Received: [65,1471889554673262,8658327088018463]
2014-06-25 15:34:24+0200 [Guest       28912] Received: [68,4406464655528414,8658327088018463,{},[2,3)
2014-06-25 15:34:24+0200 [Guest       28912] Received: [50,1471889554675782,{},[5)
2014-06-25 15:34:24+0200 [Guest       28912] Result: 5
...

The Crossbar example configuration has started a WAMP router and a guest worker running the PHP/Thruway based application component. It also runs a Web server for serving static Web content.

Open the frontend

Open http://localhost:8080/ (or wherever Crossbar runs) in your browser. When you watch the browser's JavaScript console, you should see

Hooray! That means: it works;)

You have just called a PHP procedure from JavaScript running in the browser. The call was transferred via WAMP, and routed by Crossbar.io between the application front- and backend components.

Hacking the code

All the PHP backend code is in the file client.php. All the JavaScript frontend code is in web/index.html.