Prici.io

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NestJs Integration ​

Getting Started ​

Create a new NestJs app.

bash
nest new prici-nest

Installing Dependencies ​

Install Prici's sdk.

bash
npm install @prici/sdk

Environment Variables (optional)

If you need to manage environment variables in your project, you should either install @nestjs/config or a more general solution like dotenv.

bash
npm install @nestjs/config
# or
npm install dotenv

Setup ​

Environment variables (optional) ​

Create a .env file at the root folder, paste these in and update the values.

bash
# JWT Token to be used
# when sending requests
# to Prici service
PRICI_TOKEN=eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJ0ZW5hbnQiOiJkZWZhdWx0IiwiaWQiOiIxIn0.jSp5c6WCjtJ5E5c2325pWzMsaxpwDJnr6TcPcE2xTKA
# Prici service base URL
PRICI_BASE_URL=http://0.0.0.0:9000

Adding Prici To NestJs ​

Open main.module.ts, import PriciModule and add it to the array of imports

typescript
...
import { PriciModule } from "@prici/sdk/nest";

@Module({
  imports: [
    PriciModule.forRoot({
      priciUBaseUrl: "" // required but can be omitted if PRICI_BASE_URL is set. Prici service base URL
      token: "" // required but can be omitted if PRICI_TOKEN is set. JWT token used when sending requests to Prici service
      defaultErrorMessage: "" // optional, default message for the guard
    }),
  ],

...

Using the SDK ​

Open the controller/provider file you wish to use the SDK at and then import PriciService from @prici/sdk/nest Now you can inject PriciService using NestJs DI system and use the SDK.

typescript
import { PriciService } from "@prici/sdk/nest";

@Controller()
export class AppController {
   constructor(private priciService: PriciService) {}
}

Full route example:

typescript
const featureId = "f723c4be-99ad-40dd-bc47-9f7524c27cb5";

@Controller()
export class AppController {
    constructor(private appService: AppService, private priciService: PriciService) {
    }

    @Post("todos")
    async createTodo(@Body() body: any) {
        const state = await this.priciService.sdk.getFieldState('demo-account', featureId);
    
        if (!state.isAllowed) {
            throw new BadRequestException("limit reached");
        }
        const todo = this.appService.createTodo(body);

        this.priciService.sdk.incrementField('demo-account', featureId).catch()

        return todo;
    }
}

Using Guards ​

Prici currently has one guard.

This guard is called IsAllowedGuard and its job is to validate that a user has not reached its limit quota before your route handler runs and if all is well, it will update the new usage when sending the response back.

To use this guard, first follow "Getting Started" and "Setup" sections of this guide and then add these imports:

typescript
import { UseGuards } from '@nestjs/common';
import { IsAllowedGuard } from "@prici/sdk/nest";

Now you can use the guard as a route guard.

typescript
@Controller()
export class AppController {
    constructor(private appService: AppService) {
    }

    @Post("todos")
    @UseGuards(IsAllowedGuard())
    createTodo(@Body() body: any) {
        return this.appService.createTodo(body);
    }
}

Guard Options ​

You can optionally pass an object to IsAllowedGuard with the following options:

typescript
{
  sdk?: // A `PriciSdk` instance to be used instead of the default instance.
  fieldId?: // The id of the field to be checked and potentially incremented.
  errorMessage?: // Custom error message, defaults to 'payment required'.
  incrementAmount?: // The amount by which the field should be incremented if the state check passes.
  getAccountId?: // Returns account id associated with the current request
  getFieldId?: // Returns field id associated with the current request.
  getError?: // Returns the error message should be sent in response, if not provided default message will be used.
  getIncrementAmount?: // Returns the amount by which the field should be incremented.
}