IdentifiablePostgresPersistence<T extends IIdentifiable<K>, K>

Extends: PostgresPersistence

Description

The IdentifiablePostgresPersistence class allows you to create persistence components that store data in PostgreSQL databases and implement a number of CRUD operations over data items with unique ids.

Important points

• The data items must implement the IIdentifiable interface.
• In basic scenarios child classes shall only override the getPageByFilter, getListByFilter or deleteByFilter operations with a specific filter function.
• All other operations can be used out of the box.
• In complex scenarios child classes can implement additional operations by accessing this._collection and this._model properties.

Configuration parameters

• table: (optional) PostgreSQL table name
• schema: (optional) PostgreSQL schema name

connection(s):

• discovery_key: (optional) key to retrieve the connection from IDiscovery
• host: host name or IP address
• port: port number (default: 27017)
• uri: resource URI or connection string with all parameters in it

credential(s):

• store_key: (optional) key to retrieve the credentials from ICredentialStore
• username: (optional) username
• password: (optional) user’s password

options:

• connect_timeout: (optional) number of milliseconds to wait before timing out when connecting a new client (default: 0)
• idle_timeout: (optional) number of milliseconds a client must sit idle in the pool and not be checked out (default: 10000)
• max_pool_size: (optional) maximum number of clients the pool can contain (default: 10)

References

• *:logger:*:*:1.0 - (optional) ILogger components to pass log messages
• *:discovery:*:*:1.0 - (optional) IDiscovery services
• *:credential-store:*:*:1.0 - (optional) credential stores to resolve credentials (ICredentialStore)

Constructors

Creates a new instance of the persistence component.

IdentifiablePostgresPersistence(String? tableName, String? schemaName) : super(tableName, schemaName);

• tableName: string - (optional) a table name.
• schemaName: string - (optional) a schema name.

Fields

Instance methods

convertFromPublicPartial_

Converts the given object from the public partial format.

dynamic convertFromPublicPartial_(value)

• value: the object to convert from the public partial format.
• returns: dynamic - the initial object.

create

Creates a data item.

Future<T?> create(IContext? context, T? item) async

• context: IContext - (optional) a context to trace execution through a call chain.
• item: T - item to be created.
• returns: Future<T?> - created item

deleteById

Deletes a data item by it’s unique id.

Future<T?> deleteById(IContext? context, K? id) async

• context: IContext - (optional) a context to trace execution through a call chain.
• id: K - id of the item to be deleted
• returns: Future<T?> - deleted item

deleteByIds

Deletes multiple data items by their unique ids.

Future deleteByIds(IContext? context, List ids) async

• context: IContext - (optional) a context to trace execution through a call chain.
• ids: List - ids of data items to be deleted.

getListByIds

Gets a list of data items retrieved by given unique ids.

Future<List> getListByIds(IContext? context, List ids) async

• context: IContext - (optional) a context to trace execution through a call chain.
• ids: List - ids of data items to be retrieved
• returns: Future<List> - data list

getOneById

Gets a data item by its unique id.

Future<T?> getOneById(IContext? context, K id) async

• context: IContext - (optional) a context to trace execution through a call chain.
• id: K - id of data item to be retrieved.
• returns: Future<T?> - data item

set

Sets a data item. If the data item exists it updates it. Otherwise, it creates a new data item.

Future<T?> set(IContext? context, T? item) async

• context: IContext - (optional) a context to trace execution through a call chain.
• item: T - item to be set.
• returns: Future<T?> - updated item

update

Updates a data item.

Future<T?> update(IContext? context, T? item) async

• context: IContext - (optional) a context to trace execution through a call chain.
• item: T - item to be updated.
• returns: Future<T?> - updated item

updatePartially

Updates only a few selected fields in a data item.

Future<T?> updatePartially(IContext? context, K? id, AnyValueMap? data) async

• context: IContext - (optional) a context to trace execution through a call chain.
• id: K - id of the data item to be updated.
• data: AnyValueMap - map with fields to be updated.
• returns: Future<T?> - updated item

Examples

     class MyPostgresPersistence extends IdentifiablePostgresPersistence<MyData, String> {
       MyPostgresPersistence() : super('mydata', null);

       @override
       void defineSchema_() {
         clearSchema();
         ensureSchema_('CREATE TABLE ' +
             tableName_! +
             ' (id TEXT PRIMARY KEY, key TEXT, content TEXT)');
         ensureIndex_(tableName_! + '_key', {'key': 1}, {'unique': true});
       }

       Future<DataPage<Dummy>> getPageByFilter(
           IContext? context, FilterParams? filter, PagingParams? paging) {
         filter = filter ?? FilterParams();
         var key = filter.getAsNullableString('key');
         var filterCondition = "";
         if (key != null) filterCondition += "key='" + key + "'";
         return super
             .getPageByFilter_(context, filterCondition, paging, null, null);
       }
     }
     var persistence = MyPostgresPersistence();
     persistence
         .configure(ConfigParams.fromTuples(["host", "localhost", "port", 5432]));
     await persistence.open(null);
     var item = await persistence.create(null, MyData());
     var page = await persistence.getPageByFilter(
         null, FilterParams.fromTuples(["key", "ABC"]), null);
     print(page.data);
     var deleted = await persistence.deleteById(null, '1');