Dart - bucket.on()

Create a new bucket notification trigger when certain files are created or deleted.

import 'package:nitric_sdk/nitric.dart';
import 'package:nitric_sdk/resources.dart';
// Create a readable, writable, and deletable reference to an 'assets' bucket
final assets = Nitric.bucket("assets").allow([
BucketPermission.read,
]);
// The request will contain the name of the file `key` and the type of event `type`
assets.on(BlobEventType.delete, '*', (ctx) async {
print("A file named ${ctx.req.file.key} was deleted");
return ctx;
});
assets.on(BlobEventType.write, '/images/cat', (ctx) async {
print("A cat image was created");
return ctx;
});
assets.on(BlobEventType.write, '/images/dog', (ctx) async {
final dogImage = await ctx.req.file.read();
print(dogImage)
return ctx;
});

Parameters

  • Name
    blobEventType
    Required
    Required
    Type
    BlobEventType.write or BlobEventType.delete
    Description

    The notification type for a triggered event, either on a file write or a file delete.

  • Name
    keyPrefixFilter
    Required
    Required
    Type
    String
    Description

    The file prefix filter that must match for a triggered event. If multiple filters overlap across notifications, an error will be thrown when registering the resource.

  • Name
    middleware
    Required
    Required
    Type
    BlobEventHandler
    Description

    The middleware (code) to be triggered by the bucket notification being triggered.

Available trigger types:

BlobEventType.write

Run when a file in the bucket is created using: file.write()

BlobEventType.delete

Run when a file in the bucket is deleted using: file.delete()

Trigger type cloud mapping

PermissionAWSGCPAzure
BlobEventType.writes3:ObjectCreated:*OBJECT_FINALIZEMicrosoft.Storage.BlobCreated
BlobEventType.deletes3:ObjectRemoved:*OBJECT_DELETEMicrosoft.Storage.BlobDeleted
Last updated on Oct 16, 2024