@autocodingsystems/gateway-client/lib/api/getjson.js

Library and commandline utility to control the acs gateway - device drivers for the most common industrial production line devices

var http = require('http');
const { URL } = require('url');

function readjson() {
    var savedres, savedrej;

    var next = new Promise((res, rej) => {
        savedres = res;
        savedrej = rej;
    });

    var handler = function (response) {
        var body = '';
        response.setEncoding('utf8');
        response.on('data', (chunk) => {
            body += chunk;
        });
        response.on('end', () => {
            try {
                var bodyobj = JSON.parse(body || "{}");
                if (typeof bodyobj === 'string') {
                    bodyobj = {Message: bodyobj};
                }

                if (response.statusCode === 200) {
                    savedres(bodyobj);
                } else {
                    savedrej(Object.assign({StatusCode: response.statusCode}, bodyobj));
                }

            } catch (e) {
                console.log(body);
                savedrej(e);
            }
        });
        response.on('error', savedrej);
    }

    return {handler, next}
}

function getJson(host, options) { 
    return new Promise( async (res, rej) => {
        const {handler, next} = readjson();

        const url = new URL(host);
        const requestopts = Object.assign(
            {},
            {
                protocol: url.protocol,
                hostname: url.hostname,
                method: 'GET',
                port: url.port,
                auth: (url.username || url.password) ? `${url.username}:${url.password}` : null,
                headers: {}
            },
            options
        );

        if (typeof options.data === 'object') {
            requestopts.headers['Content-Type'] = 'application/json';
        }

        var req = http.request(requestopts);
        req.once('response', handler);
        req.once('error', rej);
        if (options.data) {
            if (typeof options.data === 'object') {
                req.write(JSON.stringify(options.data));
            } else {
                req.write(options.data);
            }
        }
        req.end();

        try {
            var body = await next;
            res(body);
        } catch (e) {
            rej(e);
        }
    });
}


module.exports = getJson;