openmct/src/api/objects/ObjectAPI.js
2020-09-14 11:17:31 -07:00

334 lines
12 KiB
JavaScript

/*****************************************************************************
* Open MCT, Copyright (c) 2014-2020, United States Government
* as represented by the Administrator of the National Aeronautics and Space
* Administration. All rights reserved.
*
* Open MCT is 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.
*
* Open MCT includes source code licensed under additional open source
* licenses. See the Open Source Licenses file (LICENSES.md) included with
* this source code distribution or the Licensing information page available
* at runtime from the About dialog for additional information.
*****************************************************************************/
define([
'lodash',
'objectUtils',
'./MutableObject',
'./RootRegistry',
'./RootObjectProvider',
'EventEmitter'
], function (
_,
utils,
MutableObject,
RootRegistry,
RootObjectProvider,
EventEmitter
) {
/**
* Utilities for loading, saving, and manipulating domain objects.
* @interface ObjectAPI
* @memberof module:openmct
*/
function ObjectAPI() {
this.eventEmitter = new EventEmitter();
this.providers = {};
this.rootRegistry = new RootRegistry();
this.rootProvider = new RootObjectProvider.default(this.rootRegistry);
}
/**
* Set fallback provider, this is an internal API for legacy reasons.
* @private
*/
ObjectAPI.prototype.supersecretSetFallbackProvider = function (p) {
this.fallbackProvider = p;
};
/**
* Retrieve the provider for a given identifier.
* @private
*/
ObjectAPI.prototype.getProvider = function (identifier) {
if (identifier.key === 'ROOT') {
return this.rootProvider;
}
return this.providers[identifier.namespace] || this.fallbackProvider;
};
/**
* Get the root-level object.
* @returns {Promise.<DomainObject>} a promise for the root object
*/
ObjectAPI.prototype.getRoot = function () {
return this.rootProvider.get();
};
/**
* Register a new object provider for a particular namespace.
*
* @param {string} namespace the namespace for which to provide objects
* @param {module:openmct.ObjectProvider} provider the provider which
* will handle loading domain objects from this namespace
* @memberof {module:openmct.ObjectAPI#}
* @name addProvider
*/
ObjectAPI.prototype.addProvider = function (namespace, provider) {
this.providers[namespace] = provider;
};
/**
* Provides the ability to read, write, and delete domain objects.
*
* When registering a new object provider, all methods on this interface
* are optional.
*
* @interface ObjectProvider
* @memberof module:openmct
*/
/**
* Create the given domain object in the corresponding persistence store
*
* @method create
* @memberof module:openmct.ObjectProvider#
* @param {module:openmct.DomainObject} domainObject the domain object to
* create
* @returns {Promise} a promise which will resolve when the domain object
* has been created, or be rejected if it cannot be saved
*/
/**
* Update this domain object in its persistence store
*
* @method update
* @memberof module:openmct.ObjectProvider#
* @param {module:openmct.DomainObject} domainObject the domain object to
* update
* @returns {Promise} a promise which will resolve when the domain object
* has been updated, or be rejected if it cannot be saved
*/
/**
* Delete this domain object.
*
* @method delete
* @memberof module:openmct.ObjectProvider#
* @param {module:openmct.DomainObject} domainObject the domain object to
* delete
* @returns {Promise} a promise which will resolve when the domain object
* has been deleted, or be rejected if it cannot be deleted
*/
/**
* Get a domain object.
*
* @method get
* @memberof module:openmct.ObjectProvider#
* @param {string} key the key for the domain object to load
* @returns {Promise} a promise which will resolve when the domain object
* has been saved, or be rejected if it cannot be saved
*/
/**
* Get a domain object.
*
* @method get
* @memberof module:openmct.ObjectAPI#
* @param {module:openmct.ObjectAPI~Identifier} identifier
* the identifier for the domain object to load
* @returns {Promise} a promise which will resolve when the domain object
* has been saved, or be rejected if it cannot be saved
*/
ObjectAPI.prototype.get = function (identifier) {
identifier = utils.parseKeyString(identifier);
const provider = this.getProvider(identifier);
if (!provider) {
throw new Error('No Provider Matched');
}
if (!provider.get) {
throw new Error('Provider does not support get!');
}
return provider.get(identifier);
};
ObjectAPI.prototype.delete = function () {
throw new Error('Delete not implemented');
};
ObjectAPI.prototype.isPersistable = function (domainObject) {
let provider = this.getProvider(domainObject.identifier);
return provider !== undefined
&& provider.create !== undefined
&& provider.update !== undefined;
};
/**
* Save this domain object in its current state. EXPERIMENTAL
*
* @private
* @memberof module:openmct.ObjectAPI#
* @param {module:openmct.DomainObject} domainObject the domain object to
* save
* @returns {Promise} a promise which will resolve when the domain object
* has been saved, or be rejected if it cannot be saved
*/
ObjectAPI.prototype.save = function (domainObject) {
let provider = this.getProvider(domainObject.identifier);
let result;
if (!this.isPersistable(domainObject)) {
result = Promise.reject('Object provider does not support saving');
} else if (hasAlreadyBeenPersisted(domainObject)) {
result = Promise.resolve(true);
} else {
if (domainObject.persisted === undefined) {
this.mutate(domainObject, 'persisted', domainObject.modified);
result = provider.create(domainObject);
} else {
this.mutate(domainObject, 'persisted', domainObject.modified);
result = provider.update(domainObject);
}
}
return result;
};
/**
* Add a root-level object.
* @param {module:openmct.ObjectAPI~Identifier|function} an array of
* identifiers for root level objects, or a function that returns a
* promise for an identifier or an array of root level objects.
* @method addRoot
* @memberof module:openmct.ObjectAPI#
*/
ObjectAPI.prototype.addRoot = function (key) {
this.rootRegistry.addRoot(key);
};
/**
* Modify a domain object.
* @param {module:openmct.DomainObject} object the object to mutate
* @param {string} path the property to modify
* @param {*} value the new value for this property
* @method mutate
* @memberof module:openmct.ObjectAPI#
*/
ObjectAPI.prototype.mutate = function (domainObject, path, value) {
const mutableObject =
new MutableObject(this.eventEmitter, domainObject);
return mutableObject.set(path, value);
};
/**
* Observe changes to a domain object.
* @param {module:openmct.DomainObject} object the object to observe
* @param {string} path the property to observe
* @param {Function} callback a callback to invoke when new values for
* this property are observed
* @method observe
* @memberof module:openmct.ObjectAPI#
*/
ObjectAPI.prototype.observe = function (domainObject, path, callback) {
const mutableObject =
new MutableObject(this.eventEmitter, domainObject);
mutableObject.on(path, callback);
return mutableObject.stopListening.bind(mutableObject);
};
/**
* @param {module:openmct.ObjectAPI~Identifier} identifier
* @returns {string} A string representation of the given identifier, including namespace and key
*/
ObjectAPI.prototype.makeKeyString = function (identifier) {
return utils.makeKeyString(identifier);
};
/**
* Given any number of identifiers, will return true if they are all equal, otherwise false.
* @param {module:openmct.ObjectAPI~Identifier[]} identifiers
*/
ObjectAPI.prototype.areIdsEqual = function (...identifiers) {
return identifiers.map(utils.parseKeyString)
.every(identifier => {
return identifier === identifiers[0]
|| (identifier.namespace === identifiers[0].namespace
&& identifier.key === identifiers[0].key);
});
};
ObjectAPI.prototype.getOriginalPath = function (identifier, path = []) {
return this.get(identifier).then((domainObject) => {
path.push(domainObject);
let location = domainObject.location;
if (location) {
return this.getOriginalPath(utils.parseKeyString(location), path);
} else {
return path;
}
});
};
/**
* Uniquely identifies a domain object.
*
* @typedef Identifier
* @memberof module:openmct.ObjectAPI~
* @property {string} namespace the namespace to/from which this domain
* object should be loaded/stored.
* @property {string} key a unique identifier for the domain object
* within that namespace
*/
/**
* A domain object is an entity of relevance to a user's workflow, that
* should appear as a distinct and meaningful object within the user
* interface. Examples of domain objects are folders, telemetry sensors,
* and so forth.
*
* A few common properties are defined for domain objects. Beyond these,
* individual types of domain objects may add more as they see fit.
*
* @property {module:openmct.ObjectAPI~Identifier} identifier a key/namespace pair which
* uniquely identifies this domain object
* @property {string} type the type of domain object
* @property {string} name the human-readable name for this domain object
* @property {string} [creator] the user name of the creator of this domain
* object
* @property {number} [modified] the time, in milliseconds since the UNIX
* epoch, at which this domain object was last modified
* @property {module:openmct.ObjectAPI~Identifier[]} [composition] if
* present, this will be used by the default composition provider
* to load domain objects
* @typedef DomainObject
* @memberof module:openmct
*/
function hasAlreadyBeenPersisted(domainObject) {
return domainObject.persisted !== undefined
&& domainObject.persisted === domainObject.modified;
}
return ObjectAPI;
});