express-reducer

Middleware for express responses.

Express-reducer mutate response json body according to client requirements like graphQL this is will improve client side performance check usage section for more details

Getting started

$ npm install express-reducer

Then in your middleware

  const express = require('express')
  const app = express() 
  const reducer = require('express-reducer') 
  app.use(reducer)     

Usage

Just hookup with express and we are good to go

Using with objects and array responses

app.get('/object', function (req, res) {
  res.json({
    name:"jon doe",
    age: 20,
    profile_image: "http://url.com/image",
    phone:"(011)111526456",
    address:"lorem ipsum dolor sit amet meaning "
  });
})
 

The above route will return entire object but the client just need name and profile_image but creating multiple end points with different response is tedious.

using express-reducer we can solve this issue similar to GraphQL client can pass what they need client can pass Pluck keyword as GET parameter along with required object keys

for example

http://api.dev/object?pluck=name,profile_image

response will be look like this

 {
    "name":"jon doe",
    "profile_image": "http://url.com/image"
 }

array responses

we can use express-reducer with array responses

but currently express-reducer does not support nested reductions

Example

app.get('/characters', function (req, res) {
  res.json([
        {stark: 'arya', lannister: 'tyrion', targaryen: 'daenerys', Greyjoy: 'Theon'},
        {stark: 'rob', lannister: 'jaime', targaryen: 'Viserys', Greyjoy: 'Yara'},
        {stark: 'brandon', lannister: 'tyrion', targaryen: 'Rhaegar', Greyjoy: 'balon'},
        {stark: 'sansa', lannister: 'tywin', targaryen: 'Aegon', Greyjoy: 'euron'}
      ] 
  );
});

we can filter out these characters based on the family like this

http://api.dev/characters?pluck=stark,targaryen

response will be look like this

[
  {
    "stark":"arya",
    "targaryen":"daenerys"
  },
  {
    "stark":"rob",
    "targaryen":"Viserys"
  },
  {
    "stark":"brandon",
    "targaryen":"Rhaegar"
  },
  {
    "stark":"sansa",
    "targaryen":"Aegon"
  }
]

See the mocha tests for some more examples.

License

The MIT license

Copyright © 2016 Sarath kumar (sarath.me )