@wildebeest/persistance v0.2.3

Persistance Module

Installation

npm install --save @wildebeest/persistance

Requirements

It's usefull to know these libraries:

• inversify
• @wildebeest/js-modules

Sometimes, you want to store data during entire session or event for some months. It may be a login token, user preferences, GDPR consent and so on. This module provide a way to read and write persistant data. In it's basic form, there is only Cookie storage available, but you can create your own storage and use it with this modules service.

Use Persistant Storage

PersistanceService allowes you to read and write data. It does not matter where is data gonna be stored. PersistanceService is available via Container. You can find container instance in register and boot methods of your Module. Also you can use Dependency Injection and pass this service in any method as a parameter.

Reading data

foo(persistanceService: PersistanceService): void
{
    let storedValue: any = persistanceService->read("token", null)
}

First parameter is a name of required data. Second parameter is a default value, that will be returned if no value is found. This method returns JSON

Writing data

foo(persistanceService: PersistanceService): void
{
    persistanceService->write("token", {
        id: 1,
        user_name: "foo"
    });
}

First parameter is the name of stored data and second parameter is value to be stored. All data will be transformed to string and stored as a string.

Create New Storage Type

If storing data in Cookie is not good enough, than you can create your own storage. All you need to do is create class that implments Storage interface and enable it.

class MyStorage implements Storage
{
    public length: number;
    clear(): void { ... }
    getItem(key: string): string { ... }
    key(index: number): string { ... }
    setItem(key: string, value: string): void { ... }
    removeItem(key: string): void { ... }
}

Enable New Storage Type

If you have created new Storage type, then you have to tell PersistanceService to use this new storage. You cen do thad, in boot method of your Module, by adding these lines.

class MyModule implements Module
{
    boot(container: Container): void
    {
        let persistanceService: PersistanceService = container.get(PersistanceService);
        persistanceService.setStorage(new MyStorage());
    }
}