Viacheslav Eremin | Node Learning

(FRONT) FRONT (2023)

Node Learning

I like writing with Node API, for example with this code I make support my site by years, and finally I had time to publish it to Github https://github.com/Alex-1557/Node-FindReplace. And this is description of my first huge commercial project with Node and Express.

Developer workflow. Developer workflow mean (1)install nodemon to automatic reload server, (2) setup correct launch.json on VS Code config and (3) setup script on package.json

Common Express pipeline. (1) define various environment constant in .env with package dotenv, (2) define route endpoint in./routes/index.js, (3) define Express and function StartServer with all parameters for Express.USE(), (4) define Error handling middleware, (5) startServer.

add API endpoint. To add endpoint need to do 3 point - (1) add endpoint to Index.js, (2) and method to API controller and (3) add DTO object, (4) ValidateDTO function.

Strip gateway. Strip controller has 3 method:

   1:  router.post('/webhook', async function(req, res) {

   2:      await stripeController.stripeWebhook(req, res);

   3:  });

   4:  router.get('/getbillinginfo', validate(false), async function(req, res) {

   5:      await stripeController.getSubscriptionInfo(req, res);

   6:  });

7:

   8:  router.get('/cancelsubscription', validate(false), async function(req, res) {

   9:      await stripeController.cancelSubscription(req, res);

  10:  });

MySQL Query. For working with SQL I simple add a query with "?" instead parameters and pass parameters to query. In this case I also used uid generator.

Pack complex object (like firebase access object) with Node Buffer.From function

Various additional protection. Define in config JWT secret key and Static protection key and check it.

GraphQL request

Various Axios request to 3-rd party API

And now I decide to improve my skills and take lecture online from Maximilian Schwarzmüller:

1. Node.JS and Express

1 - Module Introduction.mp4
2 - Executing TypeScript Code with Node.js.mp4
3 - Setting up a Project.mp4
4 - Finished Setup & Working with Types (in Node + Express Apps).mp4
5 - Adding Middleware & Types.mp4
6 - Working with Controllers & Parsing Request Bodies.mp4
7 - More CRUD Operations.mp4
8 - Wrap Up.mp4

Node used only JS, not TS.

Ts_node allow excute TS, its cool tool for development, but not applicable to production with Express server

Initialize Node project and setup correct parameters on TsConfig.

This way is possible, but with Experimental mode, we don't use it, just use TS

Install Express server and Body-Parser (to parse request). Install NodeMon to support HotReload.

We listen port 3000, But Express require @Types, because currently we work without additional Library. So, Install @Types for Node.JS

Configure Typescript - ModuleResolution is Node and no lobrary.

This is JS way, not TS, because Express has no types

And now Express has Types

Js result of TS compilation

Npm Start will start Nodemon

We start Nodemon and switch to second Bash

This is JS way, we don't need it, switch to TS Import directive

Get/Post doing nothing, but Patch require ID on URL Path

Import Routes to main app, we handle only Routes from Todos, other API not be handled.

And registered MiddleWare with App.Use. This is Typical request Handler for MiddleWare to call Regular Middleware function

Request Handler with 4 parameters is Middleware with Error Handling

So, this is our Error Handler to catch Any error Request and with return Status 500

Create TodoS API, controller with Logic of application API

This is common Request processing function

This of shortcut of Request processing handler

Create Models Folder with Model ToDo and Import this Model

Declare TODOS array as asrray of models ToDo

Initialize key of Array with Random ID, cast body as Text and Push new data to TODOS Array, we don't store anything to DB currently

Import controller function to main App and pass reference to CreateToDo function to Post handler

Not execute function with '()' only pass reference to it

Create Response JSON on controller with Status code

Import JSON processing function Body-Parser

And register JSON as Middleware, Now JSON processor will working for any Request and extract Key from JSON Body

And currently we expect Text property on any JSON body on any our correct Request (Path Todos, port 3000).

Check API and new ToDo created correctly.

This is our current final JS code processed on Express server

Create CRUD operation, next controller Entry Point is GetTodos and UpdateTodo

Import GetToDo and check.

After code changing we have empty array because server restarted, but after restart all working fine

Create Delete method on Controller, ID is mandatory segment of URL

But TS don't know anything about mandatory URL segment

Therefore we need to define parameter type of RequestHandler by using Generic, what kind of body receive RequestHandler

And now we can see that body contains exactly ID, exactly the key what we define on Route

Extract value of Text property

We need to create Predicate function to JS Filter with ID from URL as key

If expected Key is missing on Request we Throw Error And Error Handler will Catch this error

Convert Response body as JSON and pass reference to this function to Router

Check, All CRUD Api working fine!

)

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Link to this page: http://www.vb-net.com/NodeLearning/Index.htm

Node Learning

1. Node.JS and Express

2. DigitalOcean

3. EggHead

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