NEST GPS SERVER

Description

A GPS server for Nestjs framework. This server was based on freshworkstudio/gps-tracking-nodejs but it was build from ground up without externals dependencies.

Protocols

It only supports an Echo protocol for testing, GPS103 and GK103. More protocols will be added in the future.

You can also add easy new protocols by implementing the GpsAdapterInterface and passing the class in the module initialization.

export class Echo implements GpsAdapterInterface {
    device: AbstractGpsDevice;

    async parse_data(data: string | Buffer): Promise<GpsMessagePartsInterface> {
        let str_data = data.toString().trim();
        let response = {
            action: GPS_MESSAGE_ACTION.PING,
            cmd: "Echo",
            data: str_data,
            device_id: "1234567890"
        };

        if (str_data == "login")
            response.action = GPS_MESSAGE_ACTION.LOGIN_REQUEST;

        return response;
    }
    async get_alarm_data(message: GpsMessagePartsInterface): Promise<GpsGeoDataInterface> {
        return {
            status: 'alarm',
            date: new Date(),
            latitude: 0,
            longitude: 0,
            custom: message.data
        };
    }
    async get_ping_data(message: GpsMessagePartsInterface): Promise<GpsGeoDataInterface> {
        this.device.send(`${JSON.stringify(message)}\r\n`);
        return {
            date: new Date(),
            latitude: 0,
            longitude: 0,
            custom: message.data
        };
    }
    async send_device_authorized(): Promise<void> {
        await this.device.send("Echo loged\r\n");
        return;
    }
    async send_device_request_login(): Promise<void> {
        await this.device.send("Please you must login using the login word\r\n");
        return;
    }
    async get_other_actions(parts: GpsMessagePartsInterface): Promise<GpsOtherActionsDataInterface> {
        return {
            custom: parts.data
        };
    }
    async request_logout(): Promise<boolean> {
        await this.device.send("Please logout\r\n");
        return true;
    }
    async set_refresh_time(interval: number): Promise<boolean> {
        return true;
    }

    async login_request(uid: string, message: GpsMessagePartsInterface): Promise<boolean> {
        return true;
    }
}

import { Module } from '@nestjs/common';
import { AppController } from './app.controller';
import { AppService } from './app.service';
import { GpsServerModule, Echo } from '@aerosales10/nest-gps-server';
@Module({
  imports: [GpsServerModule.forRoot({
    port: 8086,
    adapter: Echo
  })],
  controllers: [AppController],
  providers: [AppService],
})
export class AppModule {}

You can also modify an existing protocol by extending it's class

import { GPS103 as GPS103CORE, GpsMessagePartsInterface, GpsPingEvent, GpsAlarmEvent } from "@aerosales10/nest-gps-server";
import { AppService } from "../app.service";
import { Injectable } from "@nestjs/common";
@Injectable()
export class GPS103 extends GPS103CORE {
    appService: AppService;
    constructor(appService: AppService) {
        super();
        this.appService = appService;
    }

    async login_request(uid: string, message: GpsMessagePartsInterface): Promise<boolean> {
        // For example a database query that validates the device login
        let result = await this.appService.login_request(uid, message);
        // If device login was validated correctly then subscribe to device events
        if (result) {
            this.device.on('disconnect', this.handle_disconnect.bind(this));
            this.device.on('ping', this.handle_ping.bind(this));
            this.device.on('alarm', this.handle_alarm.bind(this));
        }
        // Returns true if the device was login correctly or false otherwise
        return result;
    }

    async handle_disconnect(uid: string): Promise<void> {
        await this.appService.disconnect_request(uid);
    }

    async handle_ping(ping_event: GpsPingEvent): Promise<void> {
        this.appService.geo_data(ping_event);
    }

    async handle_alarm(alarm_event: GpsAlarmEvent): Promise<void> {
        this.appService.geo_data(alarm_event);
    }
}

Installation

npm install @aerosales10/nest-gps-server --save

Importing the server module

import { Module } from '@nestjs/common';
import { AppController } from './app.controller';
import { AppService } from './app.service';
import { GpsServerModule } from '@aerosales10/nest-gps-server';
@Module({
  imports: [GpsServerModule.forRoot({
    port: 8086
  })],
  controllers: [AppController],
  providers: [AppService],
})
export class AppModule {}

License

Nest GPS server is MIT licensed