Generate Node App With Express

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To make Node app with express framework,
many things are needed i.e -

• Environment where the server is made.
• Generic Responses are set, in which form their is need.
• Generic Routing need to be set.
• Logging where their is a need and many more.

Now I would suggest for module - Express App Generator

So, what this Module Provide to us -

• An Environment where server is Run on Any Particular Port.
• Generic Router with unlimited Middle-wares can be set.
• Give Generic Response as Data ,Items etc.
• Obviously a Logger which helps to Log things.

Installation -

npm install express-app-generator --save

The generated app Provide us some default express Features like -

bodyParser.json();
bodyParser.urlencoded({extended: true});
bodyParser({ limit: ‘50mb’, keepExtensions: true });
(’view engine’, ‘ejs’); //for dynamic views

• express static path `public` folder in root of app folder
• if port is null it use default port `3000`

Generate Express App

let appGenrator=require(‘express-app-generator’);
appGenrator.generate(3789, function(err,app){
 if(err){
 return console.log(err);
 }
 // your express app is Ready to use
 //you can check this on http://localhost:3789
 console.log(app)
});

N O T E -
If you want to change express properties
you can change it by update `app.use()` or `app.set()`;

Routing

Their are Some Required things to be followed -

• The `api` folder in root of app is must and in this folder all the .js files will be like `users.js` not `user.js` , `employees.js` not `employee.js`
  which means `s` or `es` sufix is must.
• The `logs` folder is required ,this folder is use for
  logging the logs in JSON files ,which we get as in console.

What this Module Provides in routing ?

This Router Provides Simple CRUD Mechanism. In which Combinations of Arrays and Objects (telling you at down) are use To Build it.`appRouter();` method which is present in app generator helps to make Routing in Flexible way.

Lets get started for Routing -

//REST or CRUD
let api= app.appRouter; 
 //app is Express genrated app (above define how to get it)
 api.model(‘users’)
 .register(‘REST’, [ authentication ]); //REST or CRUD

N O T E -
This will make URL as http://localhost:3789/api/users .

We can use `REST` or `CRUD` Keyword to -`get`,`create`,`update`,`delete`,`get,search` these methods ready to use but for this, you must have all these methods present in `/api/users.js` file .

The array which is present just after the `REST` is use for middle-wares.
Suppose, I want to make authentication every time so the function of
authentication will be pass in the middle-ware Array.

Things `REST` Or `CRUD` Gives - (in api/users.js file)

• If the Request is for POST then it go for -

exports.create=(req,res)=>{};

• If the Request is for GET then it go for -

exports.get=(req,res)=>{};
// http://localhost:3789/api/users/:id

- If the Request is for GET (ALL) then it go for -

exports.search=(req,res)=>{};
// http://localhost:3789/api/users Here many query params ? can use.

• If the Request is for PUT then it go for -

exports.update=(req,res)=>{};

• If the Request is for DELETE then it go for -

exports.delete=(req,res)=>{};

N O T E -
All the the Middle-ware functions must have parameters `(req ,res ,next)` where
req,res are request response express generated objects and next is the
callback function which will call when one middleware work is DONE and
it will go to next middle-ware function (if present) in that array and perform same, then go the main function in the `users.js`.

Now I know how to make all middle-wares with one main function ( with REST or CRUD ).
This module also provide us to set in Routing in Manual Way -

• In register `action` and `method` is Requied.
• fiter for One Middleware and filters for Multiples.
• For Single Request -

api.model(‘users’)
 .register({
 action: ‘GET’,
 method: ‘get’, // method must present inside users.js
 url: ‘/:id’,
 filters: [authentication] //middlewares 
 });
 
 // URL will be -
 // http://localhost:3789/api/users/:id

• For Multiple Requests -

api.model(‘users’)
 .register([
{
 action: ‘POST’,
 method: ‘create’
 },
{
 action: ‘POST’,
 method: ‘createWithProfile’,
 url: ‘/withProfile’,
 filter: authentication
 },
 {
 action: ‘POST’,
 method: ‘importer’,
 url: ‘/importer’,
 filter: authentication
 },
 {
 action: ‘POST’,
 method: ‘createWhenSignIn’,
 filter: authentication
 },
 {
 action: ‘PUT’,
 method: ‘update’,
 url: ‘/:id’,
 filters: [authentication, groupCode]
 },
 {
 action: ‘GET’,
 method: ‘get’,
 url: ‘/:id’,
 filters: [authentication, groupCode]
 },
 {
 action: ‘GET’,
 method: ‘search’,
 filters: [authentication, groupCode]
 },
 {
 action: ‘GET’,
 method: ‘searchInGroup’,
 url: ‘/from/group’,
 filters: [authentication, groupCode]
 },
 {
 action: ‘GET’,
 method: ‘getLeader’,
 url: ‘/get/leader/:id’,
 filters: [authentication, groupCode]
 }
]);

N OT E-
`api` keyword in URL is Constant all over the Router.
So, your base url will be http://localhost:3789/api/ .

Responses

Here are Four Types of Responses — All the Responses are of status
Code is 200 .

DATA

• It can take one or two params `data,message`, `data` is mandatory.
• It is use as -

res.data({
 name:”Leo”,
 age:21
 });
 
 //res which you get from any query

• This will give Response -

{
 “isSuccess”:true,
 “data”:{
        name:”Leo”,
        age:21
     }
 }

PAGE

• It can take one or two params `items, pageSize, pageNo, totalRecordsCount`.
• `items` is mandatory.
• Can also use for Paginations.
• It is use as -

res.page([
            {
            name:”Leo”,
            age:21
            },{
            name:”Hardy”,
            age:22
            }
        ]);
 
 //res which you get from any query

• This will give Response -

{
 “isSuccess”:true,
 “items”:[
           {
            “name”:”Leo”,
            “age”:21
            },{
            “name”:”Hardy”,
            “age”:22
           }
         ],
 pageSize:2
 }

SUCCESS

• It can takes one params `message`, it is mandatory.
• Can Use for Sending Successful Signature message.
• It is use as -

res.success(`user successfully deleted`);

• This will give Response -

{
 “isSuccess”:true,
 “message”:”user successfully deleted”
 }

FAILURE

• It can takes two params `error, message`
  `error` it is mandatory.
• Can Use for Sending Error Signature message.
• It is use as -

res.failure(`user Hardy already present`);

• This will give Response -

{
 “isSuccess”:false,
 “message”:”user Hardy already present”
 }

Hope you like it.

Stay Connected ;)