RESTGLUE: multi-api restful client using superagent & promises

Usage

<script type="text/javascript" src="https://cdn.jsdelivr.net/es6-promise/3.1.2/es6-promise.min.js"></script> <!-- older browsers -->
<script type="text/javascript" src="dist/restglue.min.js"></script>

or in nodejs just do npm install restglue superagent and then:

var restglue = require('restglue')

Example: single api

var myapi = new restglue()
myapi.headers['Content-Type'] = 'application/json'
myapi.addEndpoint("pizza")

Not really exciting yet, but now you can do calls like so:

myapi.pizza.getAll()
.then( function(json){  // json-result of GET /pizza
                        // call json.getResponse() for raw response (headers etc)
})
.catch( function(err){
  console.log("could not get pizza")
})

NOTE: use new restglue("http://api.foo.com/v1") to automatically prepend an external apiurl to all endpoints, and make sure you got CORS setup on your server when doing requests from the browser.

Restful endpoint function reference

getAll(query, headers)                - will do GET     /pizza
post(payload, query, headers)         - will do POST    /pizza      {..}
get(id, query, headers)               - will do GET     /pizza/{id}
put(id, payload, query, headers)      - will do PUT     /pizza/{id} {..}
delete(id, payload, query, headers)   - will do DELETE  /pizza/{id} {..}
patch(id, payload, query, headers)    - will do PATCH   /pizza/{id} {..}
options(id, payload, querym headers)  - will do OPTIONS /pizza/{id} {..}

NOTE: query and headers are optional and are used only for that request.

Custom endpoints + monkeypatch

myapi.pizza.customPost = restglue.prototype.request.bind( this, "post",  '/foo/bar',  {payload:true}, {queryfoo:1, querybar:2}, {X-HEADER-FOO:12} )
myapi.pizza.customGet  = restglue.prototype.request.bind( this, "get",  '/foo/bar' )

Also, you can monkeypatch these function to alter restglue's behaviour:

restglue.prototype.addEndpointg( resourcename  )
restglue.prototype.afterRequestg(cb)
restglue.prototype.beforeRequestg(cb)
restglue.prototype.composeg(chain)
restglue.prototype.constructorg(apiurl)
restglue.prototype.getSandboxedUrlg(method,url)
restglue.prototype.requestg(method, url, payload, query, headers)
restglue.prototype.sandboxUrlg(url,destination)
restglue.prototype.toQueryStringg(data)

Offline sandbox

You can fake responses (for offline development etc) in 2 ways, like so:

myapi.addEndpoint("foobar")
myapi.addEndpoint("foo")

myapi.sandboxUrl('/foobar',       {'data':{"foo":true}}  ) 
myapi.sandboxUrl('/myapi',        {'path':"/js/sandbox"} )
myapi.sandboxUrl( /some.*regex/,  "/js/foo" )

myapi.foobar.getAll().then(function(data){    
  // data = {"foo":true}
})

myapi.foo.getAll().then(function(data){    
  // data = /js/sandbox/foo/get.json instead of GET {apiurl}/myapi/foo 
})

NOTE: {apiurl} is passed using new restglue({apiurl:"http://foo.com/v1"})

Chained endpoints, multiple api's

Byebye async spaghetti, welcome clean code.

Combine multiple endpoints into one call:

myapi.pizza.getCookPageRanking = myapi.compose([
  function(i)  { return myapi.pizza.getAll({"sort":"-date_create"})    },
  function(res){ return otherapi.getRanking(res.cook.profile_url)      },
  function(res){ return res.score                                      }
])("foo")

myapi.pizza.getCookPageRanking().then( function(res){
  // res is '4'
}).catch( function(err){ ..  })

Example: query args

myapi.pizza.getAll( {"sort":"-date_create"} )
.then( function(res){
  // result of GET /pizza?sort=-date_create
}
var password = "bar"
myapi.headers['Authorization'] = 'Basic '+btoa( login+":"+password )

// do calls

Example: response headers

myapi.pizza.getAll()
.then( function(res){
  var headers = res.getResponse().headers
})

NOTE: Make sure you have CORS configured properly on your server, otherwise certain headers won't be accessible in javascript.

Example: hooks

beforeRequest and afterRequest allow you to massage the request or response

myapi.beforeRequest( function(config){
  // format the input for an exotic api, before doing the actual request
  config.payload = { type: "payload", payload:config.payload } 
})

Here's how to simply prevent unnecessary calls

var cache = {get:{}}

myapi.beforeRequest( function(config){
  if( config.method == "get" && cache.get[config.url] ) return cache.get[config.url]
})

myapi.afterRequest( function(config, res, err){
  if( config.method == "get" && !err ) cache.get[ config.url ] = res
})

NOTE: optionally you can store a new Date().getTime() timestamp, and bypass the cache when expired

Example: Multi-api and mult-versioned wrappers

This easifies iterative, backwardscompatible development:

function getApi(){
  var v1       = new restglue("http://api.foo.com/v1"),
  var v2       = new restglue("http://api.foo.com/v2"),
  var api      = {
    ga: new restglue("https://www.googleapis.com/analytics/v3") 
  }

  // *TODO* call addEndpoint(...) on v1,v2 and googleanalytics

  // ok, we're assuming the v1 and v2 endpoints are setup 
  // so now we set v1 endpoints as default 
  for( i in v1 ) api[i] = v1[i]

  // but upgrade the pizza endpoint to v2 
  api.pizza = v2.pizza 

  return api 
}

var myapi = getApi()

Example: HTTP auth

var login          = "foo"
var password       = "bar"

myapi.addEndpoint("user/current")
myapi.headers['Authorization'] = 'Basic '+btoa( login+":"+password 

myapi.pizza.getAll()
.then( function(res){

  // authenticated response

})
.catch( function(err){
  console.log(err)
})

Example: HTTP auth + bearer token

var login          = "foo"
var password       = "bar"

myapi.addEndpoint("user/current")

myapi['user/current'].getAll(false, { 'Authorization': 'Basic '+btoa( login+":"+password ) })
.then( function(res){

  if( ! res.bearer_hash ) throw new Exception("AUTH_FAILED")
  myapi.headers['Authentication'] = "bearer "+res.bearer_hash 

})
.catch( function(err){
  console.log(err)
})

Why superagent and not fetch?

Eventhough I prefer fetch, this module relies on superagent and not on fetch because:

• I had some weird experiences with fetch-polyfill vs native fetch (I guess it needs a bit of time)
• XHR request seems a more robust choice before fetch really takes over
• superagent seems battletested and has a lot of extensions and plugins

Also i noticed projects like restful.js, frisbee, superagent-defaults, superagent-jsonapify,superagent-ls,superapi, superagent-pool, super-res

but I needed a little bit more and less, in short I need:

• a drop-in solution (not all js devs have ES6/ES7 transpilertoolchain-experience)
• easy chaining of endpoints, from multiple api's (hence async helpers included)
• promises
• requestpool cache but with TTL (hence the hooks, so the beforeRequest-hook can return a cached response)
• compose a superapi (swap around endpoint versions)