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🚀 Nestjs BareBones Controllers & ReqObjects
- typescript(disciplined)
- oops(SOLID principles)
- scalable/testable/loosely coupled production grade architecture boilerplate setup
-
npm i -g @nestjs/cli
# cmd line nest -v # config your nest backend nest new nest-basics-api # choices npm or yarn or pnpm
**app.module.ts is the root of the api**
**everything is imported inside app.module and then this is exported and bootstrapped inside main.ts to create the nest backend**
🔧 building the api
1. 📩 Controllers
**Handles incoming request from client and sends back response**
** ✏ never write the buisness logic inside the controllers**
- In nest we define controllers via decorators that provide meta data about what functionality a particular code block will have
**the access decorators import @nestjs/common**
Controllers
|- student.controller.ts
# student.controller.ts
import { Controller } from @nestjs/common
# Controller will tell nest that this is a controller based class
@Controller('students')
class StudentController {
}
**every single route inside studentController is going to start as /students**
**it can be specified with a @Get() decorator that this is a get request**
@Get()
getStudents(){
// return all students data
}
**make sure to import the student.controller.ts inside the app.module.ts**
✔ running dev server first time
npm run start:dev
# make sure the main.ts is just under the src directory
-
nested routes like /students/:studentId
@Get('/:studentId') getStudentById(){ return "Get Student By Id" }
-
https://docs.nestjs.com/controllers
nest g controller <controllerName> --no-spec # only add --no-spec flag if you dont need unit test file for this controller
# to run tests
npm run test:watch
2. Request Objects (extracting pieces of info from request like params)
make use @param () decorator in Nest for GET
# student object in student ID
@Get('/:studentId')
getStudentById(
@Param () params: {studentId: string}
) {
console.log(params)
return 'Get Student By Id';
}
-
further it can be simplified while the required params can be destructured at the time of decorator defination
# @Param('destructuredObjectFromParams') @Param ('studentId') studentId: string console.log(studentId)
make use @Body () decorator in Nest for POST
@Post()
createStudent(
@Body() body
) {
return `Create's New Student with details\n ${JSON.stringify(body)}`;
}
use @Body & @Parma together for PUT
@Put('/:studentId')
updateStudentById(
@Param('studentId') studentId: string,
@Body() body
) {
return `Update's\n student id: ${JSON.stringify(studentId)}\n with new data ${body}`;
}
Further their are @Query, @Session, @Next and @ip() that can be useful refer- https://docs.nestjs.com/controllers#request-object
@Put('/:studentId')
updateTeacherOfStudentById(
@Param('teachersId') teachersId: string,
@Param('studentId') studentId: string,
@Ip() clientIP: string
) {
return `clientIP: ${clientIP}\nUpdate's Teacher with ID: ${teachersId}\n Associated To Student With Id: ${studentId}`;
}
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