API Client Implementation in Javascript (Nodejs)

• Usage
• Module

Usage

```js

const Client = require('./espocrm-api-client');

const client = new Client( 'https://your-espocrm-site', 'API_KEY', 'SECRET_KEY' // optional, if hmac auth is used );

// POST example

const payload = { name: 'Some name', };

client .request('POST', 'Account', payload) .then(response => { // success console.log(response); }) .catch(response => { // error console.log(response.statusCode, response.statusMessage); });

// GET example

const params = { maxSize: 5, where: [ { type: 'equals', attribute: 'type', value: 'Customer', }, ], select: ['id', name'], };

client .request('GET', 'Account', params) .then(response => { console.log(response); }) .catch(response => { // error console.log(response.statusCode, response.statusMessage); }); ```

Module

File espocrm-api-client.js:

```js class Client {

/**
 *
 * @param {string} url
 * @param {string} apiKey
 * @param {string|null} [secretKey]
 * @param {{
 *     port?: number,
 *     timeout?: number,
 * }} [options]
 */
constructor(url, apiKey, secretKey = null, options = {}) {
    this.url = url;
    this.apiKey = apiKey;
    this.secretKey = secretKey;

    if (this.url.substr(-1) === '/') {
        this.url = this.url.substr(0, this.url.length -1);
    }

    this.options = options;

    this.urlPath = '/api/v1/';
    this.isHttps = url.toLowerCase().indexOf('https') === 0;
}

/**
 *
 * @param {'GET'|'POST'|'PUT'|'DELETE'|'PATCH'|'OPTIONS'} method
 * @param {string} action
 * @param {Record} [data]
 * @return {Promise}
 */
request(method, action, data) {
    method = method || 'GET';
    method = method.toUpperCase();

    let url = this._buildUrl(action);

    const headers = {};

    if (this.apiKey && this.secretKey) {
        const crypto = require('crypto');

        const string = method + ' /' + action;

        const authString = this.apiKey + ':' +
            crypto.createHmac('sha256', this.secretKey).update(string).digest('hex');

        const authPart = Buffer.from(authString).toString('base64');

        headers['X-Hmac-Authorization'] = authPart;
    } else if (this.apiKey) {
        headers['X-Api-Key'] = this.apiKey;
    } else {
        throw new Error('Api-Key is not set.');
    }

    let postData;

    if (data) {
        if (method === 'GET') {
            const querystring = require('querystring');

            url += '?' + querystring.stringify({searchParams: JSON.stringify(data)});
        } else {
            postData = JSON.stringify(data);

            headers['Content-Type'] = 'application/json';
            headers['Content-Length'] = Buffer.byteLength(postData);
        }
    }

    return new Promise((resolve, reject) => {
        const o = {
            headers: headers,
            method: method,
        };

        if (this.options.port) {
            o.port = this.options.port;
        }

        if (this.options.timeout) {
            o.timeout = this.options.timeout;
        }

        const h = this.isHttps ? require('https') : require('http');

        const req = h.request(url, o, res => {
            let data = '';

            res.on('data', chunk => {
                data += chunk;
            });

            res.on('end', () => {
                if (res.statusCode < 200 || res.statusCode > 299) {
                    reject(res);

                    return;
                }

                try {
                    data = JSON.parse(data);
                } catch (e) {
                    console.error(`Error: Could not parse response`);
                    reject({});

                    return;
                }

                resolve(data, res);
            });
        });

        req.on('error', e => {
            console.error(`Error: ${e.message}`);

            reject(e);
        });

        if (data && method !== 'GET') {
            req.write(postData);
        }

        req.end();
    });
}

_buildUrl(action) {
    return this.url + this.urlPath + action;
}

}

if (module && module.exports) { module.exports = Client; } ```