Featured

Feature Flags

An express.js module for setting feature flags that turn on/off depending on environment and session.

Setup

There are 3 steps:

1. Install it

   npm install featured

2. Configure it

   featured = require('featured');
   featured.configure({
     // file: './conf/rules.js' // is rules.js by default
     // , functionName: '__f' // is __featured by default
   });

3. Add it to express middleware

   app = express.createServer();
   app.configure(function(){
        
     [...]
   
     // Session should be setup prior to featured
     app.use(express.session);
   
     app.use(featured.init);
   
     [...]
   
   });

Config

There is 1 configuration file:

1. Located in rules.js by default:

   module.exports = {
     'awesomeStuff': false,
     'betterStuff': function(session){
   
       if(process.env.NODE_ENV=='production')
         return false;
   
       if(session.accountId)
         return true;
   
       return false;
   
     }
   }

Usage

Flags makes itself available in 3 places:

1. In express middleware

   app.get('/betterStuff', function(req, res, next){
      
     if(req.__featured('betterStuff'))
       res.send(true);
     else
       res.send(false);
   
   });

2. In express templates (jade in this example)

   p Stuff
   if __featured('betterStuff')
     p Better Stuff

3. In express templates statically generated, for use in javascript

   In template:

   script !{__featuredStatic}
   script(src='/js/script.js')

   In js/script.js:

   if(__featured('betterStuff')){
     alert('Better Stuff!')
   }

License

(The MIT License)

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the 'Software'), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.