node-red/nodes/core/logic/10-switch.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");

var operators = {
    'eq': function(a, b) { return a == b; },
    'neq': function(a, b) { return a != b; },
    'lt': function(a, b) { return a < b; },
    'lte': function(a, b) { return a <= b; },
    'gt': function(a, b) { return a > b; },
    'gte': function(a, b) { return a >= b; },
    'btwn': function(a, b, c) { return a >= b && a <= c; },
    'cont': function(a, b) { return (a + "").indexOf(b) != -1; },
    'regex': function(a, b) { return (a + "").match(new RegExp(b)); },
    'true': function(a) { return a === true; },
    'false': function(a) { return a === false; },
    'null': function(a) { return typeof a == "undefined"; },
    'nnull': function(a) { return typeof a != "undefined"; },
    'else': function(a) { return a === true; }
};

function SwitchNode(n) {
    RED.nodes.createNode(this, n);
    this.rules = n.rules;
    this.property = n.property;
    this.checkall = n.checkall || "true";
    var propertyParts = n.property.split("."),
        node = this;

    for (var i=0; i<this.rules.length; i+=1) {
        var rule = this.rules[i];
        if (!isNaN(Number(rule.v))) {
            rule.v = Number(rule.v);
            rule.v2 = Number(rule.v2);
        }
    }
        
    this.on('input', function (msg) {
        var onward = [];
        var prop = propertyParts.reduce(function (obj, i) {
            return obj[i]
        }, msg);
        var elseflag = true;
        for (var i=0; i<node.rules.length; i+=1) {
            var rule = node.rules[i];
            var test = prop;
            if (rule.t == "else") { test = elseflag; elseflag = true; }
            if (operators[rule.t](test,rule.v, rule.v2)) {
                onward.push(msg);
                elseflag = false;
                if (node.checkall == "false") { break; }
            } else {
                onward.push(null);
            }
        }
        this.send(onward);
    });
}
RED.nodes.registerType("switch", SwitchNode);