FilePersistence<T>

Abstract persistence component that stores data in flat files and caches them in memory.

Extends: MemoryPersistence

implements: IConfigurable

Description

The FilePersistence class allows you to create persistence components that store data in flat files and chache them in memory.

Important points

  • 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 the self._items property and calling the save method.

Configuration parameters

  • path: path to the file where data is stored

References

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

Constructors

Creates a new instance of the file persistence component.

public constructor(persister?: JsonFilePersister)

  • persister: JsonFilePersister - (optional) persister component that loads and saves data from/to a flat file.

Fields

_persister

JSON file persister.

protected _persister: JsonFilePersister

Instance methods

configure

Configures the component by passing its configuration parameters.

public configure(config: ConfigParams): void

  • config: ConfigParams - configuration parameters to be set.

Examples

class MyJsonFilePersistence extends FilePersistence<MyData> {
    public constructor(path?: string) {
        super(new JsonPersister(path));
    }
    
    public async getByName(correlationId: string, name: string): Promise<MyData> {
        let item = this._items.find((d) => d.name == name);
        retur item;
    }); 
     
    public async set(correlatonId: string, item: MyData): Promise<MyData> {
        this._items = this._items.filter((d) => d.name != name);
        this._items.push(item);
        await this.save(correlationId);
        return item;
    }
  
}

See also