node-red/nodes/core/logic/15-change.js

/**
 * Copyright 2013 IBM Corp.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 **/

var RED = require(process.env.NODE_RED_HOME + "/red/red");

function ChangeNode(n) {
    RED.nodes.createNode(this, n);
    this.action = n.action;
    this.property = n.property || "";
    this.from = n.from || " ";
    this.to = n.to || " ";
    this.reg = n.reg;
    var node = this;

    var makeNew = function( stem, path, value ) {
        var lastPart = (arguments.length === 3) ? path.pop() : false;
        for (var i = 0; i < path.length; i++) {
            stem = stem[path[i]] = stem[path[i]] || {};
        }
        if (lastPart) { stem = stem[lastPart] = value; }
        return stem;
    };

    this.on('input', function (msg) {
        if (node.action == "change") {
            var from = node.from;
            if (node.reg === false) {
                from = from.replace(/[-[\]{}()*+?.,\\^$|#\s]/g, "\\$&");
            }
            try {
                node.re = new RegExp(from, "g");
            } catch (e) {
                node.error("Invalid regex: "+from);
            }
            if (typeof msg[node.property] === "string") {
                msg[node.property] = (msg[node.property]).replace(node.re, node.to);
            }
        }
        //else if (node.action == "replace") {
            //if (node.to.indexOf("msg.") == 0) {
                //msg[node.property] = eval(node.to);
            //}
            //else {
                //msg[node.property] = node.to;
            //}
        //}
        else if (node.action == "replace") {
            if (node.to.indexOf("msg.") == 0) {
                makeNew( msg, node.property.split("."), eval(node.to) );
            }
            else {
                makeNew( msg, node.property.split("."), node.to );
            }
            //makeNew( msg, node.property.split("."), node.to );
        }
        else if (node.action == "delete") {
            delete(msg[node.property]);
        }
        node.send(msg);
    });
}
RED.nodes.registerType("change", ChangeNode);