gulp-etl-mysql-adapter/mysql_src.js

Extract data from mysql into gulp-etl Message Stream JSON

const mysql = require('gulp-etl-mysql-adapter')

module.exports = function (RED) {
    function MysqlSrcNode(config) {
        RED.nodes.createNode(this, config);
        this.path = config.path;
        this.config = config.config;
        this.sql = config.sql;

        let node = this;
        // console.log("config", config)

        node.on('input', function (msg, send, done) {
            try {
                let configObj;
                try {
                    if (this?.config?.trim())
                        configObj = JSON.parse(this.config);
                    else {
                        configObj = {};
                    }
                }
                catch (err) {
                    console.log("Unable to parse mysql.config: " + err);
                    node.error("Unable to parse mysql.config: " + err);
                    return;
                }
                if (!configObj)
                    configObj = {};
                if (this?.sql?.trim())
                    configObj.sql = this.sql;


                // configObj = mysql.extractConfig(configObj, msg?.config);

                // choosing here to use config and sql properties set on this node to be overridden by msg.config properties, if present. 
                // This seems to be the intuitive behavior
                configObj = mysql.extractConfig(null, msg?.config, configObj);

                // msg = RED.util.cloneMessage(msg);

                /** 
                 * plugins will be an array of objects where obj.init is a function that returns a stream. This clones well for
                 * when msg is cloned by Node-RED (for passing down multiple wires), unlike arrays of streams or other such options
                 */
                msg.plugins = [];

                // set the payload to give info on the gulp stream we're creating
                msg.payload = "mysql.src: " + node.path;
                msg.topic = "gulp-initialize";

                msg.plugins.push({
                    name: config.type,
                    // init:() => mysql.src(node.path, configObj)
                    init: () => {
                        return mysql.src(node.path, configObj)
                            .on("data", () => {
                                this.status({ fill: "green", shape: "dot", text: "active" });
                            })
                            .on("end", () => {
                                this.status({ fill: "green", shape: "ring", text: "ready" });
                            })
                            .on("error", (err) => {
                                console.error(err)
                            });
                    }
                })

                send(msg);
            }
            catch (err) {
                node.error("Error setting up for mysql.src(): " + err);
                done("Error setting up for mysql.src(): " + err);
                return;
            }
        });

    }
    RED.nodes.registerType("mysql.src", MysqlSrcNode);
}