cloud-red/src/components/runtime/lib/settings.js

Harnessing Serverless for your cloud integration needs

/**
 * 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 when = require('when');
var clone = require('clone');
var assert = require('assert');
var log = require('../../util').log; // TODO: separate module
var util = require('../../util').util;

// localSettings are those provided in the runtime settings.js file
var localSettings = null;
// globalSettings are provided by storage - .config.json on localfilesystem
var globalSettings = null;
// nodeSettings are those settings that a node module defines as being available
var nodeSettings = null;

// A subset of globalSettings that deal with per-user settings
var userSettings = null;

var disableNodeSettings = null;
var storage = null;

var persistentSettings = {
  // settings that we have passed in default properties in the cli
  init: function(settings) {
    localSettings = settings;
    for (var i in settings) {
      /* istanbul ignore else */
      if (
        settings.hasOwnProperty(i) &&
        i !== 'load' &&
        i !== 'get' &&
        i !== 'set' &&
        i !== 'available' &&
        i !== 'reset'
      ) {
        // Don't allow any of the core functions get replaced via settings
        (function() {
          var j = i;
          persistentSettings.__defineGetter__(j, function() {
            return localSettings[j];
          });
          persistentSettings.__defineSetter__(j, function() {
            throw new Error("Property '" + j + "' is read-only");
          });
        })();
      }
    }
    globalSettings = null;
    nodeSettings = {};
    disableNodeSettings = {};
  },
  load: function(_storage) {
    storage = _storage;
    return storage.getSettings().then(function(_settings) {
      globalSettings = _settings;
      if (globalSettings) {
        userSettings = globalSettings.users || {};
      } else {
        userSettings = {};
      }
    });
  },
  get: function(prop) {
    if (prop === 'users') {
      throw new Error(
        'Do not access user settings directly. Use settings.getUserSettings'
      );
    }
    if (localSettings.hasOwnProperty(prop)) {
      return clone(localSettings[prop]);
    }
    if (globalSettings === null) {
      throw new Error(log._('settings.not-available'));
    }
    return clone(globalSettings[prop]);
  },

  set: function(prop, value) {
    if (prop === 'users') {
      throw new Error(
        'Do not access user settings directly. Use settings.setUserSettings'
      );
    }
    if (localSettings.hasOwnProperty(prop)) {
      throw new Error(log._('settings.property-read-only', { prop: prop }));
    }
    if (globalSettings === null) {
      throw new Error(log._('settings.not-available'));
    }
    var current = globalSettings[prop];
    globalSettings[prop] = value;
    try {
      assert.deepEqual(current, value);
      return when.resolve();
    } catch (err) {
      return storage.saveSettings(globalSettings);
    }
  },
  delete: function(prop) {
    if (localSettings.hasOwnProperty(prop)) {
      throw new Error(log._('settings.property-read-only', { prop: prop }));
    }
    if (globalSettings === null) {
      throw new Error(log._('settings.not-available'));
    }
    if (globalSettings.hasOwnProperty(prop)) {
      delete globalSettings[prop];
      return storage.saveSettings(globalSettings);
    }
    return when.resolve();
  },

  available: function() {
    return globalSettings !== null;
  },

  reset: function() {
    for (var i in localSettings) {
      /* istanbul ignore else */
      if (localSettings.hasOwnProperty(i)) {
        delete persistentSettings[i];
      }
    }
    localSettings = null;
    globalSettings = null;
    userSettings = null;
    storage = null;
  },
  registerNodeSettings: function(type, opts) {
    var normalisedType = util.normaliseNodeTypeName(type);
    for (var property in opts) {
      if (opts.hasOwnProperty(property)) {
        if (!property.startsWith(normalisedType)) {
          throw new Error(
            "Registered invalid property name '" +
              property +
              "'. Properties for this node must start with '" +
              normalisedType +
              "'"
          );
        }
      }
    }
    nodeSettings[type] = opts;
  },
  exportNodeSettings: function(safeSettings) {
    for (var type in nodeSettings) {
      if (nodeSettings.hasOwnProperty(type) && !disableNodeSettings[type]) {
        var nodeTypeSettings = nodeSettings[type];
        for (var property in nodeTypeSettings) {
          if (nodeTypeSettings.hasOwnProperty(property)) {
            var setting = nodeTypeSettings[property];
            if (setting.exportable) {
              if (safeSettings.hasOwnProperty(property)) {
                // Cannot overwrite existing setting
              } else if (localSettings.hasOwnProperty(property)) {
                safeSettings[property] = localSettings[property];
              } else if (setting.hasOwnProperty('value')) {
                safeSettings[property] = setting.value;
              }
            }
          }
        }
      }
    }

    return safeSettings;
  },
  enableNodeSettings: function(types) {
    types.forEach(function(type) {
      disableNodeSettings[type] = false;
    });
  },
  disableNodeSettings: function(types) {
    types.forEach(function(type) {
      disableNodeSettings[type] = true;
    });
  },
  getUserSettings: function(username) {
    if (!username) {
      username = '_';
    }
    return clone(userSettings[username]);
  },
  setUserSettings: function(username, settings) {
    if (globalSettings === null) {
      throw new Error(log._('settings.not-available'));
    }
    var current = userSettings[username];
    userSettings[username] = settings;
    try {
      assert.deepEqual(current, settings);
      return when.resolve();
    } catch (err) {
      globalSettings.users = userSettings;
      return storage.saveSettings(globalSettings);
    }
  }
};

module.exports = persistentSettings;