MemoryPersistence<T> class Null safety

Abstract persistence component that stores data in memory.

This is the most basic persistence component that is only able to store data items of any type. Specific CRUD operations over the data items must be implemented in child classes by accessing this.items property and calling save method.

The component supports loading and saving items from another data source. That allows to use it as a base class for file and other types of persistence components that cache all data in memory.

References

*:logger:*:*:1.0 (optional) ILogger components to pass log messages

Example

class MyMemoryPersistence extends MemoryPersistence<MyData> {

   Future<MyData> getByName(String? correlationId, String name) async {
        var item = items.firstWhere((d) => d.name == name);
       return item;
    });

    Future<MyData> set(String correlatonId, MyData item) async {
        items = items.where((d) => d.name != name);
        items.add(item);
        await save(correlationId);
        return item;
    }
}

var persistence = MyMemoryPersistence();

persistence.set("123", { name: "ABC" })
var item = await persistence.getByName("123", "ABC")
print(item);                   // Result: { name: "ABC" }

Implemented types

Implementers

Constructors

MemoryPersistence([ILoader<T>? loader, ISaver<T>? saver]): Creates a new instance of the persistence.

Properties

hashCode → int: The hash code for this object.
read-onlyinherited
items ↔ List<T>: read / write
loader ↔ ILoader<T>?: read / write
logger ↔ CompositeLogger: read / write
maxPageSize ↔ int: read / write
opened ↔ bool: read / write
runtimeType → Type: A representation of the runtime type of the object.
read-onlyinherited
saver ↔ ISaver<T>?: read / write

Methods

clear(String? correlationId) → Future: Clears component state.
override
close(String? correlationId) → Future: Closes component and frees used resources.
override
create(String? correlationId, T item) → Future<T?>: Creates a data item.
deleteByFilterEx(String? correlationId, Function filter) → Future: Deletes data items that match to a given filter.
getCountByFilterEx(String? correlationId, Function? filter) → Future<int>: Gets a count of data items retrieved by a given filter.
getListByFilterEx(String? correlationId, Function? filter, Function? sort, dynamic select) → Future<List<T>>: Gets a list of data items retrieved by a given filter and sorted according to sort parameters.
getOneRandom(String? correlationId, Function? filter) → Future<T?>: Gets a random item from items that match to a given filter.
getPageByFilterEx(String? correlationId, Function? filter, PagingParams? paging, Function? sort, [dynamic select]) → Future<DataPage<T>>: Gets a page of data items retrieved by a given filter and sorted according to sort parameters.
isOpen() → bool: Checks if the component is opened.
override
noSuchMethod(Invocation invocation) → dynamic: Invoked when a non-existent method or property is accessed.
inherited
open(String? correlationId) → Future: Opens the component.
override
save(String? correlationId) → Future: Saves items to external data source using configured saver component.
setReferences(IReferences references) → void: Sets references to dependent components.
override
toString() → String: A string representation of this object.
inherited

Operators

operator ==(Object other) → bool: The equality operator.
inherited