node-red/red/runtime/nodes/context.js

/**
 * Copyright 2015, 2016 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 clone = require("clone");
var when = require("when");
var util = require("../util");

function createContext(id,seed) {
    var data = seed || {};
    var obj = seed || {};
    obj.get = function get(key) {
        return util.getMessageProperty(data,key);
    };
    obj.set = function set(key, value) {
        util.setMessageProperty(data,key,value);
    }
    return obj;
}

var contexts = {};
var globalContext = null;

function getContext(localId,flowId) {
    var contextId = localId;
    if (flowId) {
        contextId = localId+":"+flowId;
    }
    if (contexts.hasOwnProperty(contextId)) {
        return contexts[contextId];
    }
    var newContext = createContext(contextId);
    if (flowId) {
        newContext.flow = getContext(flowId);
        if (globalContext) {
            newContext.global = globalContext;
        }
    }
    contexts[contextId] = newContext;
    return newContext;
}
function deleteContext(id,flowId) {
    var contextId = id;
    if (flowId) {
        contextId = id+":"+flowId;
    }
    delete contexts[contextId];
}
function clean(flowConfig) {
    var activeIds = {};
    var contextId;
    var node;
    for (var id in contexts) {
        if (contexts.hasOwnProperty(id)) {
            var idParts = id.split(":");
            if (!flowConfig.allNodes.hasOwnProperty(idParts[0])) {
                delete contexts[id];
            }
        }
    }
}
module.exports = {
    init: function(settings) {
        globalContext = createContext("global",settings.functionGlobalContext || {});
    },
    get: getContext,
    delete: deleteContext,
    clean:clean
};