pip-services4-persistence-node
Version:
Persistence Components for Pip.Services in Node.js / ES2017
143 lines (142 loc) • 6 kB
TypeScript
/** @module persistence */
import { IContext } from 'pip-services4-components-node';
import { IIdentifiable } from 'pip-services4-data-node';
import { AnyValueMap } from 'pip-services4-commons-node';
import { MemoryPersistence } from './MemoryPersistence';
import { IWriter } from '../write/IWriter';
import { IGetter } from '../read/IGetter';
import { ISetter } from '../write/ISetter';
import { ILoader } from '../read/ILoader';
import { ISaver } from '../write/ISaver';
/**
* Abstract persistence component that stores data in memory
* and implements a number of CRUD operations over data items with unique ids.
* The data items must implement [[https://pip-services4-node.github.io/pip-services4-commons-node/interfaces/data.iidentifiable.html IIdentifiable interface]].
*
* In basic scenarios child classes shall only override [[getPageByFilter]],
* [[getListByFilter]] or [[deleteByFilter]] operations with specific filter function.
* All other operations can be used out of the box.
*
* In complex scenarios child classes can implement additional operations by
* accessing cached items via this._items property and calling [[save]] method
* on updates.
*
* @see [[MemoryPersistence]]
*
* ### References ###
*
* - <code>\*:logger:\*:\*:1.0</code> (optional) [[https://pip-services4-node.github.io/pip-services4-components-node/interfaces/log.ilogger.html ILogger]] components to pass log messages
*
* ### Examples ###
*
* class MyMemoryPersistence extends IdentifiableMemoryPersistence<MyData, string> {
*
* private composeFilter(filter: FilterParams): any {
* filter = filter || new FilterParams();
* let name = filter.getAsNullableString("name");
* return (item) => {
* if (name != null && item.name != name)
* return false;
* return true;
* };
* }
*
* public async getPageByFilter(context: IContext, filter: FilterParams, paging: PagingParams): DataPage<MyData> {
* return await super.getPageByFilter(context, this.composeFilter(filter), paging, null, null);
* }
*
* }
*
* let persistence = new MyMemoryPersistence();
*
* let item = await persistence.create("123", { id: "1", name: "ABC" });
*
* let page = await persistence.getPageByFilter(
* "123",
* FilterParams.fromTuples("name", "ABC"),
* null
* );
* console.log(page.data); // Result: { id: "1", name: "ABC" }
*
* item = await persistence.deleteById("123", "1");
*/
export declare class IdentifiableMemoryPersistence<T extends IIdentifiable<K>, K> extends MemoryPersistence<T> implements IWriter<T, K>, IGetter<T, K>, ISetter<T> {
/**
* Creates a new instance of the persistence.
*
* @param loader (optional) a loader to load items from external datasource.
* @param saver (optional) a saver to save items to external datasource.
*/
constructor(loader?: ILoader<T>, saver?: ISaver<T>);
/**
* Gets a list of data items retrieved by given unique ids.
*
* @param context (optional) a context to trace execution through call chain.
* @param ids ids of data items to be retrieved
* @returns a list with found data items.
*/
getListByIds(context: IContext, ids: K[]): Promise<T[]>;
/**
* Gets a data item by its unique id.
*
* @param context (optional) a context to trace execution through call chain.
* @param id an id of data item to be retrieved.
* @returns a found data item or <code>null</code> if nothing was found.
*/
getOneById(context: IContext, id: K): Promise<T>;
/**
* Creates a data item.
*
* @param context (optional) transaction id to trace execution through call chain.
* @param item an item to be created.
* @returns a created data item.
*/
create(context: IContext, item: T): Promise<T>;
/**
* Sets a data item. If the data item exists it updates it,
* otherwise it create a new data item.
*
* @param context (optional) transaction id to trace execution through call chain.
* @param item a item to be set.
* @returns a set data item.
*/
set(context: IContext, item: T): Promise<T>;
/**
* Updates a data item.
*
* @param context (optional) transaction id to trace execution through call chain.
* @param item an item to be updated.
* @returns the updated data item.
*/
update(context: IContext, item: T): Promise<T>;
/**
* Updates only few selected fields in a data item.
*
* @param context (optional) transaction id to trace execution through call chain.
* @param id an id of data item to be updated.
* @param data a map with fields to be updated.
* @returns the updated data item.
*/
updatePartially(context: IContext, id: K, data: AnyValueMap): Promise<T>;
/**
* Deleted a data item by it's unique id.
*
* @param context (optional) transaction id to trace execution through call chain.
* @param id an id of the item to be deleted
* @returns the deleted data item.
*/
deleteById(context: IContext, id: K): Promise<T>;
/**
* Deletes multiple data items by their unique ids.
*
* @param context (optional) a context to trace execution through call chain.
* @param ids ids of data items to be deleted.
*/
deleteByIds(context: IContext, ids: K[]): Promise<void>;
/**
* Checks if value is empty
* @param value any value
* @returns true if value empty, other false
*/
protected isEmpty(value: any): boolean;
}