file-based design-pattern to organize expressa & express REST/db middleware

Usage

require('expressa-folder')(expressa, app)
expressa.addListener('ready', 100, >(){
  expressa.folderDir = __dirname+"/lib"
  expressa.initFolder('foo')      // will require expressa db/REST-listener code if collection 'foo' exist
  expressa.initFolder('foo/bar')  // will setup custom express point
  // optional: generate REST client for in the browser at /api/client.js
  require('expressa-client').middleware({expressa:expressa,  app:app}) 
})

This will automatically fetch the following files if present:

| file | expressa listener | creates express endpoint | note | | - | - | - | - | | lib/foo/get.js | yes | no | requires data/collection/foo.js to exist | | lib/foo/post.js | yes | no | requires data/collection/foo.js to exist | | lib/foo/put.js | yes | no | requires data/collection/foo.js to exist | | lib/foo/delete.js | yes | no | requires data/collection/foo.js to exist | | lib/foo/schema.js | yes | no | requires data/collection/foo.js to exist | | lib/foo/functions.js | no | no | all db objects will inherit these functions | | lib/foo/swagger.js | no | no | only when expressa-swagger is installed | | lib/foo/bar/get.js | no | yes | bare express endpoint without expressa schema-validation| | lib/foo/bar/swagger.js | no | no | only when expressa-swagger is installed |

Example: lib/foo/get.js

module.exports = function(expressa, app){
  return function(req, collection, doc, resolve, reject) {
    // do stuff with the response data (doc)
    resolve(doc)
  })
}

Example: lib/foo/functions.js

module.exports = function(expressa, app){
  return {
    addPropertyFoo: () => {
      this.foo = "bar"
    }
  }
}

Now you can easily access helper functions on the server:

expressa.db.foo.find({})
.then( function(items){
  items.map( (i) => i.addPropertyFoo() )
})

Example: lib/foo/bar/get.js (bare express)

module.exports = function(expressa,app){
  return function(req, res, next){
			res.writeHeader(200, {"Content-Type":"application/json"})
			res.end( JSON.stringify({"foo":"bar"}) )
  }
}

Voila..this will automatically setup a 'foo/bar' express-endpoint

Example: robust custom endpoint

NOTE: The non-expressa endpoint above, is a simple express endpoint. Unfortunately express endpoints have zero input validation (unlike expressa endpoints).

Here's how to do it for express as well..let assume we want the user to submit to a mailinglist:

// lets add the endpoint
expressa.initFolder('users/mailinglist')

And now lets write lib/users/mailinglist/post.js:

var typeshave = require('typeshave') // json schema validator
var typesafe  = typeshave.typesafe

var schema = require('./../../../../data/collection/users.json').schema
schema.required = ["firstname", "email"] // overrule required properties

module.exports = function(expressa, app ){

  return function(req, res, next){

    res.writeHeader(200, {"Content-Type":"application/json"})

    try{ 

      typesafe(schema, function(){

        expressa.db.users.find({email:req.body.email})
        .then( function(user){
          if(user.length != 0) throw "user "+req.body.email+" already exist"
          return expressa.db.users.create( req.body )
        })
        .then(function(id){
          res.end( JSON.stringify({code:0, id:id}) )
        })
        .catch(function(err){
          res.end( JSON.stringify({"code":1, error:err}) )
        })

      })(req.body) 

    }catch(e){
      return res.end( JSON.stringify({"code":2, error:e}) )
    }

  }
}

Boom...if we would now post {} to our endpoint:

$ curl -X POST 'http://localhost:3001/api/users/mailinglist' --data '{}'

Then the server will reply:

{ data: {},
  errors:
   { message: 'Missing required property: email',
     dataPath: '',
     schemaPath: '/required/0',
     subErrors: null },
  schema:
   { type: 'object',
     additionalProperties: false,
     properties:
      { meta: [Object],
        email: [Object],
        password: [Object],
        firstname: [Object],
        lastname: [Object],
        roles: [Object] }
     required: [ 'email', 'firstname' ],

Example: lib/foo/swagger.js

This will add (or overwrite) swagger documentation, generated at url /api/doc using expressa-admin:

module.exports = {
  "/foo":{
    "get":{
      "parameters": [
        {
          "in": "body",
          "name": "payload",
          "description": "", 
          "required": true,
          "schema": {
            "type": "object",
            "required":["id_user"],                  // see swagger
            "properties": {                          // documentation
              "id_user":{
                "required":true, 
                "type":"string",
                "default":"lLK34LK" 
              }
            }
          }
        }    
      ],
      "responses": { },
      "tags": [ "users" ],
      "summary": "Lorem ipsum"
    }
  }
}