randia-api-builder/index.js

Samll API Builder

/**
 * Created by badhrc on 7/10/17.
 */
const config = require('./config.json')
// Imports
const express = require('express');
const morgan = require('morgan');
const cors = require('cors');
let db = null;

if (config.dbs[config.selectedDB].name = "PostgresSQL")
    db = require('./db');
else
    db = require('mysql');

// App and Config
const app = express();


//Middlewares
app.use(morgan('combined'));
app.use(cors());


module.exports.launch = function () {
    app.listen(config.APP_PORT, function () {
        "use strict";
        console.log("Listening on *:" + config.APP_PORT);
    })
}

/**
 *
 * @param METHOD
 * @param ENDPOINT
 * @param handler
 */
module.exports.addRoute = function (METHOD, ENDPOINT, handler) {
    "use strict";
    if (typeof handler !== "function")
        throw new Error('handler must be a function');
    switch (METHOD) {
        case "GET" :
            app.get(ENDPOINT, handler);
            break;
        case "POST" :
            app.post(ENDPOINT, handler);
            break;
        case "PUT" :
            app.put(ENDPOINT, handler);
            break;
        case "DELETE" :
            app.delete(ENDPOINT, handler);
            break;
        default :
            console.error("");
            throw new Error("You must use GET|POST|PUT|DELETE");
    }
    console.log(`You added a ${METHOD} Method`);
}

/**
 * Get the users from the TABLE_USER set in config.json
 * @param {function} callback that receive results
 */
module.exports.getUsers = function (callback) {
    "use strict";
    db.query("SELECT * FROM " + config.USER_TABLE_NAME, [], function (err, res) {
        "use strict";
        if (err) callback(err);
        else
            callback(null, res.rows);
    });
};

/**
 * Insert Document into DATABASE
 * @param {string} TABLE_NAME represents the table of inner data
 * @param {Array} document to uplaod
 * @param {function} handler the callback function
 */
module.exports.insertDocument = function (TABLE_NAME, document, handler) {
    "use strict";
    db.query(`INSERT INTO ${TABLE_NAME} VALUES` + getNumberOfParamsInInsertFunction(document), document, handler);
};

module.exports.deleteDocument = function(TABLE_NAME, idName, idDocument,handler) {
    "use strict";
    db.query(`DELETE FROM ${TABLE_NAME} WHERE ${idName}=$1`, idDocument, handler);
}

function getNumberOfParamsInInsertFunction(document) {
    "use strict";
    let query_string = "(";
    for (let i =0; i<=document.length;i++) {
        if (document[i] == 'DEFAULT'){
            query_string += `default, `;
            document.splice(i,1);
        }
        else
            query_string += `$${i},`;
    }
    return query_string.substr(0, query_string.length - 1) + ")";
}