My previous posting introduced EWD’s new realtime web framework and described the EWD application that demonstrates all its capabilities.
In this posting, I’ll explain how to get the framework and the example EWD application on a GT.M-based dEWDrop 5 Virtual Machine (VM). The following instructions assume that you’re using an unmodified, uncustomised instance of the dEWDrop 5 VM. There’s just a few simple steps and you should have it up and running in a few minutes:
- Start up the dEWDrop 5 VM, eg using VMWare Player
- Having determined its IP address, connect to it using a terminal session (eg using puTTY on a Windows machine) and login using the standard login credentials (vista/ewd)
- From the home (~) directory (which is where you’ll be after you login), enter the command sudo ewd_upgrade.sh This will fetch the latest build of EWD (currently 960) along with a copy of the example EWD realtime web application (ewdGateway2) which it will compile for you automatically. Ignore any permissions errors you might see – they are just warnings.
- Next navigate to the path ~/www/node (cd www/node)
- Install the latest version of the Node.js module named ewdGateway2:
- npm install ewdgateway2 (Note that ewdgateway2 is all in lower case!)
- Now you need to move a few files around:
- move or copy ~/www/node/node_modules/ewdgateway2/examples/ewdStart-gtm.js to ~/www/node
- move or copy ~/www/ewd/ewdGateway2/node/ewdGW2Mgr.js to ~/www/node
- move or copy ~/www/ewd/ewdGateway2/js/ewdGW2.js to ~/www/js
- Navigate back to ~/www/node (cd ~/www/node)
- Start up the Node.js-based ewdGateway2 module: node ewdStart-gtm
- It’s now listening for incoming SSL/HTTPS requests on port 8080
- Start a browser and point it at the example realtime web application (ewdGateway2), eg:
- https://192.168.1.87:8080/vista/ewdGateway2/index-gtm.ewd (change the IP address to the one that was assigned to your dEWDrop VM)
- Click the Proceed anyway button if the SSL warning page appears
- The login form should appear against a greyed-out ExtJS layout. The password is keepThisSecret! (This is defined in the file ~/www/node/ewdStart-gtm – find the management.password setting. If you want to change it, edit ewdStart-gtm and then stop and restart the ewdGateway2 Node.js process.
- The ewdGateway2 monitoring/management application should now be running, showing you the latest status of your Node.js-based ewdGateway2 module and its associated child Node.js processes, in addition to the EWD run-time/session environment within the VM’s GT.M database. I’ll describe its operation in more detail in a later posting, but for now feel free to explore its many options. Everything you’ll see changing in the display is happening in real-time, driven by WebSockets messages: there’s no traditional HTTP processing happening at all!
Welcome to the cool and exciting future: realtime web applications!