Hi all,
I have used context data for a few days. But today my flow stop working due to some error when loading context data. Any idea why and how to fix this?
Start Node-RED
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On Pi Node-RED works better with the Firefox or Chrome browser
Use node-red-stop to stop Node-RED
Use node-red-start to start Node-RED again
Use node-red-log to view the recent log output
Use sudo systemctl enable nodered.service to autostart Node-RED at every boot
Use sudo systemctl disable nodered.service to disable autostart on boot
To find more nodes and example flows - go to http://flows.nodered.org
Starting as a systemd service.
1 Jun 13:10:37 - [info]
Welcome to Node-RED
===================
1 Jun 13:10:37 - [info] Node-RED version: v0.20.8
1 Jun 13:10:37 - [info] Node.js version: v10.15.2
1 Jun 13:10:37 - [info] Linux 4.19.75-v7+ arm LE
1 Jun 13:10:41 - [info] Loading palette nodes
1 Jun 13:10:46 - [info] Dashboard version 2.21.0 started at /ui
1 Jun 13:10:48 - [info] Settings file : /home/pi/.node-red/settings.js
1 Jun 13:10:48 - [info] Context store : 'default' [module=localfilesystem]
1 Jun 13:10:48 - [error] Failed to start server:
1 Jun 13:10:48 - [error] Error: Error loading context store: SyntaxError: Unexpected token u in JSON at position 0
at /usr/lib/node_modules/node-red/node_modules/@node-red/runtime/lib/nodes/context/index.js:177:15
nodered.service: Succeeded.
The index.js is:
/**
* Copyright JS Foundation and other contributors, http://js.foundation
*
* 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 log = require("@node-red/util").log;
var util = require("@node-red/util").util;
var memory = require("./memory");
var flows;
var settings;
// A map of scope id to context instance
var contexts = {};
// A map of store name to instance
var stores = {};
var storeList = [];
var defaultStore;
// Whether there context storage has been configured or left as default
var hasConfiguredStore = false;
// Unknown Stores
var unknownStores = {};
function logUnknownStore(name) {
if (name) {
var count = unknownStores[name] || 0;
if (count == 0) {
log.warn(log._("context.unknown-store", {name: name}));
count++;
unknownStores[name] = count;
}
}
}
function init(_settings) {
flows = require("../flows");
settings = _settings;
contexts = {};
stores = {};
storeList = [];
hasConfiguredStore = false;
var seed = settings.functionGlobalContext || {};
contexts['global'] = createContext("global",seed);
// create a default memory store - used by the unit tests that skip the full
// `load()` initialisation sequence.
// If the user has any stores configured, this will be disgarded
stores["_"] = new memory();
defaultStore = "memory";
}
function load() {
return new Promise(function(resolve,reject) {
// load & init plugins in settings.contextStorage
var plugins = settings.contextStorage || {};
var defaultIsAlias = false;
var promises = [];
if (plugins && Object.keys(plugins).length > 0) {
var hasDefault = plugins.hasOwnProperty('default');
var defaultName;
for (var pluginName in plugins) {
if (plugins.hasOwnProperty(pluginName)) {
// "_" is a reserved name - do not allow it to be overridden
if (pluginName === "_") {
continue;
}
if (!/^[a-zA-Z0-9_]+$/.test(pluginName)) {
return reject(new Error(log._("context.error-invalid-module-name", {name:pluginName})));
}
// Check if this is setting the 'default' context to be a named plugin
if (pluginName === "default" && typeof plugins[pluginName] === "string") {
// Check the 'default' alias exists before initialising anything
if (!plugins.hasOwnProperty(plugins[pluginName])) {
return reject(new Error(log._("context.error-invalid-default-module", {storage:plugins["default"]})));
}
defaultIsAlias = true;
continue;
}
if (!hasDefault && !defaultName) {
defaultName = pluginName;
}
var plugin;
if (plugins[pluginName].hasOwnProperty("module")) {
// Get the provided config and copy in the 'approved' top-level settings (eg userDir)
var config = plugins[pluginName].config || {};
copySettings(config, settings);
if (typeof plugins[pluginName].module === "string") {
// This config identifies the module by name - assume it is a built-in one
// TODO: check it exists locally, if not, try to require it as-is
try {
plugin = require("./"+plugins[pluginName].module);
} catch(err) {
return reject(new Error(log._("context.error-loading-module2", {module:plugins[pluginName].module,message:err.toString()})));
}
} else {
// Assume `module` is an already-required module we can use
plugin = plugins[pluginName].module;
}
try {
// Create a new instance of the plugin by calling its module function
stores[pluginName] = plugin(config);
var moduleInfo = plugins[pluginName].module;
if (typeof moduleInfo !== 'string') {
if (moduleInfo.hasOwnProperty("toString")) {
moduleInfo = moduleInfo.toString();
} else {
moduleInfo = "custom";
}
}
log.info(log._("context.log-store-init", {name:pluginName, info:"module="+moduleInfo}));
} catch(err) {
return reject(new Error(log._("context.error-loading-module2",{module:pluginName,message:err.toString()})));
}
} else {
// Plugin does not specify a 'module'
return reject(new Error(log._("context.error-module-not-defined", {storage:pluginName})));
}
}
}
// Open all of the configured contexts
for (var plugin in stores) {
if (stores.hasOwnProperty(plugin)) {
promises.push(stores[plugin].open());
}
}
// There is a 'default' listed in the configuration
if (hasDefault) {
// If 'default' is an alias, point it at the right module - we have already
// checked that it exists. If it isn't an alias, then it will
// already be set to a configured store
if (defaultIsAlias) {
stores["_"] = stores[plugins["default"]];
defaultStore = plugins["default"];
} else {
stores["_"] = stores["default"];
defaultStore = "default";
}
} else if (defaultName) {
// No 'default' listed, so pick first in list as the default
stores["_"] = stores[defaultName];
defaultStore = defaultName;
defaultIsAlias = true;
} else {
// else there were no stores list the config object - fall through
// to below where we default to a memory store
storeList = ["memory"];
defaultStore = "memory";
}
hasConfiguredStore = true;
storeList = Object.keys(stores).filter(n=>!(defaultIsAlias && n==="default") && n!== "_");
} else {
// No configured plugins
log.info(log._("context.log-store-init", {name:"default", info:"module=memory"}));
promises.push(stores["_"].open())
storeList = ["memory"];
defaultStore = "memory";
}
return resolve(Promise.all(promises));
}).catch(function(err) {
throw new Error(log._("context.error-loading-module",{message:err.toString()}));
});
}
function copySettings(config, settings){
var copy = ["userDir"]
config.settings = {};
copy.forEach(function(setting){
config.settings[setting] = clone(settings[setting]);
});
}
function getContextStorage(storage) {
if (stores.hasOwnProperty(storage)) {
// A known context
return stores[storage];
} else if (stores.hasOwnProperty("_")) {
// Not known, but we have a default to fall back to
if (storage !== defaultStore) {
// It isn't the default store either, so log it
logUnknownStore(storage);
}
return stores["_"];
}
}
function followParentContext(parent, key) {
if (key === "$parent") {
return [parent, undefined];
}
else if (key.startsWith("$parent.")) {
var len = "$parent.".length;
var new_key = key.substring(len);
var ctx = parent;
while (ctx && new_key.startsWith("$parent.")) {
ctx = ctx.$parent;
new_key = new_key.substring(len);
}
return [ctx, new_key];
}
return null;
}
function createContext(id,seed,parent) {
// Seed is only set for global context - sourced from functionGlobalContext
var scope = id;
var obj = seed || {};
var seedKeys;
var insertSeedValues;
if (seed) {
seedKeys = Object.keys(seed);
insertSeedValues = function(keys,values) {
if (!Array.isArray(keys)) {
if (values[0] === undefined) {
try {
values[0] = util.getObjectProperty(seed,keys);
} catch(err) {
if (err.code === "INVALID_EXPR") {
throw err;
}
values[0] = undefined;
}
}
} else {
for (var i=0;i<keys.length;i++) {
if (values[i] === undefined) {
try {
values[i] = util.getObjectProperty(seed,keys[i]);
} catch(err) {
if (err.code === "INVALID_EXPR") {
throw err;
}
values[i] = undefined;
}
}
}
}
}
}
Object.defineProperties(obj, {
get: {
value: function(key, storage, callback) {
var context;
if (!callback && typeof storage === 'function') {
callback = storage;
storage = undefined;
}
if (callback && typeof callback !== 'function'){
throw new Error("Callback must be a function");
}
if (!Array.isArray(key)) {
var keyParts = util.parseContextStore(key);
key = keyParts.key;
if (!storage) {
storage = keyParts.store || "_";
}
var result = followParentContext(parent, key);
if (result) {
var [ctx, new_key] = result;
if (ctx && new_key) {
return ctx.get(new_key, storage, callback);
}
else {
if (callback) {
return callback(undefined);
}
else {
return undefined;
}
}
}
} else {
if (!storage) {
storage = "_";
}
}
context = getContextStorage(storage);
if (callback) {
if (!seed) {
context.get(scope,key,callback);
} else {
context.get(scope,key,function() {
if (arguments[0]) {
callback(arguments[0]);
return;
}
var results = Array.prototype.slice.call(arguments,[1]);
try {
insertSeedValues(key,results);
} catch(err) {
callback.apply(err);
return
}
// Put the err arg back
results.unshift(undefined);
callback.apply(null,results);
});
}
} else {
// No callback, attempt to do this synchronously
var results = context.get(scope,key);
if (seed) {
if (Array.isArray(key)) {
insertSeedValues(key,results);
} else if (results === undefined){
try {
results = util.getObjectProperty(seed,key);
} catch(err) {
if (err.code === "INVALID_EXPR") {
throw err;
}
results = undefined;
}
}
}
return results;
}
}
},
set: {
value: function(key, value, storage, callback) {
var context;
if (!callback && typeof storage === 'function') {
callback = storage;
storage = undefined;
}
if (callback && typeof callback !== 'function'){
throw new Error("Callback must be a function");
}
if (!Array.isArray(key)) {
var keyParts = util.parseContextStore(key);
key = keyParts.key;
if (!storage) {
storage = keyParts.store || "_";
}
var result = followParentContext(parent, key);
if (result) {
var [ctx, new_key] = result;
if (ctx && new_key) {
return ctx.set(new_key, value, storage, callback);
}
else {
if (callback) {
return callback();
}
return undefined;
}
}
} else {
if (!storage) {
storage = "_";
}
}
context = getContextStorage(storage);
context.set(scope, key, value, callback);
}
},
keys: {
value: function(storage, callback) {
var context;
if (!storage && !callback) {
context = stores["_"];
} else {
if (typeof storage === 'function') {
callback = storage;
storage = "_";
}
if (callback && typeof callback !== 'function') {
throw new Error("Callback must be a function");
}
context = getContextStorage(storage);
}
if (seed && settings.exportGlobalContextKeys !== false) {
if (callback) {
context.keys(scope, function(err,keys) {
callback(err,Array.from(new Set(seedKeys.concat(keys)).keys()));
});
} else {
var keys = context.keys(scope);
return Array.from(new Set(seedKeys.concat(keys)).keys())
}
} else {
return context.keys(scope, callback);
}
}
}
});
if (parent) {
Object.defineProperty(obj, "$parent", {
value: parent
});
}
return obj;
}
function createRootContext() {
var obj = {};
Object.defineProperties(obj, {
get: {
value: function(key, storage, callback) {
return undefined;
}
},
set: {
value: function(key, value, storage, callback) {
}
},
keys: {
value: function(storage, callback) {
return undefined;
}
}
});
return obj;
}
function getContext(localId,flowId,parent) {
var contextId = localId;
if (flowId) {
contextId = localId+":"+flowId;
}
if (contexts.hasOwnProperty(contextId)) {
return contexts[contextId];
}
var newContext = createContext(contextId,undefined,parent);
if (flowId) {
var node = flows.get(flowId);
var parent = undefined;
if (node && node.type.startsWith("subflow:")) {
parent = node.context().flow;
}
else {
parent = createRootContext();
}
var flowContext = getContext(flowId,undefined,parent);
Object.defineProperty(newContext, 'flow', {
value: flowContext
});
}
Object.defineProperty(newContext, 'global', {
value: contexts['global']
})
contexts[contextId] = newContext;
return newContext;
}
function deleteContext(id,flowId) {
if(!hasConfiguredStore){
// only delete context if there's no configured storage.
var contextId = id;
if (flowId) {
contextId = id+":"+flowId;
}
delete contexts[contextId];
return stores["_"].delete(contextId);
}else{
return Promise.resolve();
}
}
function clean(flowConfig) {
var promises = [];
for(var plugin in stores){
if(stores.hasOwnProperty(plugin)){
promises.push(stores[plugin].clean(Object.keys(flowConfig.allNodes)));
}
}
for (var id in contexts) {
if (contexts.hasOwnProperty(id) && id !== "global") {
var idParts = id.split(":");
if (!flowConfig.allNodes.hasOwnProperty(idParts[0])) {
delete contexts[id];
}
}
}
return Promise.all(promises);
}
function close() {
var promises = [];
for(var plugin in stores){
if(stores.hasOwnProperty(plugin)){
promises.push(stores[plugin].close());
}
}
return Promise.all(promises);
}
function listStores() {
return {default:defaultStore,stores:storeList};
}
module.exports = {
init: init,
load: load,
listStores: listStores,
get: getContext,
delete: deleteContext,
clean: clean,
close: close
};
