node-red/nodes/core/logic/16-range.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 RangeNode(n) {
    RED.nodes.createNode(this, n);
    this.action = n.action;
    this.round = n.round || false;
    this.minin = Number(n.minin);
    this.maxin = Number(n.maxin);
    this.minout = Number(n.minout);
    this.maxout = Number(n.maxout);
    var node = this;

    this.on('input', function (msg) {
        var n = Number(msg.payload);
        if (!isNaN(n)) {
            if (node.action == "clamp") {
                if (n < node.minin) { n = node.minin; }
                if (n > node.maxin) { n = node.maxin; }
            }
            if (node.action == "roll") {
                if (n >= node.maxin) { n = (n - node.minin) % (node.maxin - node.minin) + node.minin; }
                if (n <  node.minin) { n = (n - node.minin) % (node.maxin - node.minin) + node.maxin; }
            }
            msg.payload = ((n - node.minin) / (node.maxin - node.minin) * (node.maxout - node.minout)) + node.minout;
            if (node.round) { msg.payload = Math.round(msg.payload); }
            node.send(msg);
        }
        else { node.log("Not a number: "+msg.payload); }
    });
}
RED.nodes.registerType("range", RangeNode);