prisme-flow/nodes/bridge/opcua/opcuabrowser.js

prisme platform flow engine

/**
 * Created by prisme.io on 09/06/2017.
 */


module.exports = function (RED) {
    "use strict";
    var opcua = require('node-opcua');
    var async = require("async");

    function OpcUaBrowserNode(config) {

        RED.nodes.createNode(this, config);

        this.item = config.item;         // OPC UA address: ns=2;i=4 OR ns=3;s=MyVariable
        this.datatype = config.datatype; // String;
        this.topic = config.topic;       // ns=3;s=MyVariable from input
        this.items = config.items;

        var node = this;

        var browseTopic = "ns=0;i=85";

        var opcuaEndpoint = RED.nodes.getNode(config.endpoint);

        var connectionOption = {};
        connectionOption.securityPolicy = opcua.SecurityPolicy[opcuaEndpoint.securityPolicy] || opcua.SecurityPolicy.None;
        connectionOption.securityMode = opcua.MessageSecurityMode[opcuaEndpoint.securityMode] || opcua.MessageSecurityMode.NONE;

        node.status({fill: "gray", shape: "dot", text: "no Items"});

        node.add_item = function (item) {
            if (item) {
                node.items.add({'item': item});
            }
        };

        function setupClient(url, callback) {

            // new OPC UA Client and browse from Objects ns=0;s=Objects
            var browseClient = new opcua.OPCUAClient(connectionOption);
            var browseSession;

            async.series([
                // First connect to server´s endpoint
                function (callback) {
                    browseClient.connect(url, callback);
                    node.log("start browse client on " + opcuaEndpoint.endpoint);
                },
                function (callback) {
                    browseClient.createSession(function (err, session) {
                        if (!err) {
                            browseSession = session;
                            node.log("start browse session on " + opcuaEndpoint.endpoint);
                            callback();
                        }
                        else {
                            callback(err);
                        }
                    });
                },
                // step 3 : browse
                function (callback) {
                    node.warn("browseTopic:" + browseTopic);
                    browseSession.browse(browseTopic, function (err, browse_result) {
                        if (!err) {
                            browse_result.forEach(function (result) {
                                result.references.forEach(function (reference) {
                                    node.add_item(reference);
                                });
                            });
                        }

                        node.status({fill: "green", shape: "dot", text: "Items: " + node.items.length});

                        callback(err);
                    });
                },
                // close session
                function (callback) {

                    node.warn("sending items " + node.items.length);
                    var msg = {payload: node.items, endpoint: opcuaEndpoint.endpoint};
                    node.send(msg);

                    node.warn("close browse session");
                    browseSession.close(function (err) {
                        if (err) {
                            node.error("session closed failed on browse");
                        }
                        callback(err);
                    });
                }
            ], function (err) {
                if (err) {
                    browseSession = null;
                    browseClient = null;
                    callback(err);
                }
            });
        }

        setupClient(opcuaEndpoint.endpoint, function (err) {
            if (err) {
                node.error(err);
                node.status({fill: "red", shape: "dot", text: "Error Items: " + node.items.length});
            }

            node.log("Browse loading Items done ...");
        });

        node.on("input", function (msg) {

            browseTopic = null;

            node.warn("input browser");

            if (msg.payload.hasOwnProperty('actiontype')) {

                switch (msg.payload.actiontype) {
                    case 'browse':
                        if (msg.payload.hasOwnProperty('root')) {
                            if (msg.payload.root && msg.payload.root.hasOwnProperty('item')) {
                                if (msg.payload.root.item.hasOwnProperty('nodeId')) {
                                    browseTopic = browse_by_item(msg.payload.root.item.nodeId);
                                }
                            }
                        }
                        break;

                    default:
                        break;
                }
            }
            else {
                if (!node.topic && msg.topic) {
                    if (msg.topic) {
                        browseTopic = msg.topic;
                    }
                }
                else {
                    browseTopic = node.topic;
                }
            }

            node.items = []; // clear items - TODO: may it becomes usable in Edit window of the node

            if (!browseTopic) {
                browseTopic = browse_to_root();
            }

            setupClient(opcuaEndpoint.endpoint, function (err) {
                if (err) {
                    node.error(err);
                    node.status({fill: "red", shape: "dot", text: "Error Items: " + node.items.length});
                }
                node.log("Browse loading Items done ...");
            });

            msg.endpoint = opcuaEndpoint.endpoint;
            msg.payload = node.items;

            node.send(msg);
        });

        function browse_by_item(nodeId) {
            node.log("Browse to root " + nodeId);
            return nodeId;
        }


        function browse_to_root() {
            node.warn("Browse to root Objects");
            return "ns=0;i=85"; // OPC UA Root Folder Objects
        }
    }

    RED.nodes.registerType("OpcUa-Browser", OpcUaBrowserNode);
};