UploadState constructor
Represents the current uploading state of a specific file resource.
This model is emitted by the StorageUpload system to reflect whether
a given file is actively being uploaded. It allows reactive UI elements
or controllers to respond to upload start/stop events.
The resourceId identifies the file uniquely, while isUploading indicates whether the upload is currently in progress.
Example:
final state = UploadState(resourceId: 'file_789', isUploading: true);
print(state.isUploading); // true
Implementation
const UploadState({required this.resourceId, required this.isUploading});