`@dandi/common` provides common types and utilities for the rest of the `@dandi` system.
npm install @dandi/common@dandi/common provides common types and utilities for the rest of the@dandi system.
@dandi/common does not have any dependencies on NodeJS, and therefore
can be used on classes shared with projects targeted for the web.
The Disposable interface allows implementing classes to define
behavior for cleaning up resources like IO streams, database
connections, as well as Observable and other event subscriptions.
When used with @dandi/core, Disposable instances are
automatically disposed by Dandi at the end of their lifecycle.
``typescript
class MyService implements Disposable {
constructor(private dbClient: DbClient) {}
public dispose(reason: string): void {
this.dbClient.release()
}
}
`
Disposable is also a static class provides several utility functions:
- isDisposable(obj) - Returns true if the object implementsdispose()
; otherwise, false.
- makeDisposable(obj, disposeFn) - Modifies the specified object to
add the provided {@see DisposeFn} as the Disposable.dispose
implementation. If the object already has a function member named
, it is wrapped and called before the new function.
- use(obj, fn) - Invokes the specified function in a try/catch,finally
statement, then disposes the object. Returns the valuefn
returned by , or rethrows the error thrown by it.
- useAsync(obj, fn) - Same as use, but fn is invoked using await.
- remapDisposed(target, reason) - Overwrites members of the target
such that functions and property/field accessors throw an
AlreadyDisposedError, a read-only disposed property is set withtrue
the value , and the target is frozen (using Object.freeze`) to
prevent further modification.