ProgressEvent
Events measuring progress of an underlying process, like an HTTP request (for an XMLHttpRequest, or the loading of the underlying resource of an , , , or ).
interface ProgressEvent <T extends EventTarget = EventTarget> extends Event {
readonly lengthComputable: boolean;
readonly loaded: number;
readonly target: T | null;
readonly total: number;
}var ProgressEvent: {
prototype: ProgressEvent;
new (type: string, eventInitDict?: ProgressEventInit): ProgressEvent;
};