fetch function

Future<Response> fetch(Object resource, [ RequestInit<JSAny>? options ])

The global fetch() method starts the process of fetching a resource from the network, returning a promise which is fulfilled once the response is available.

The promise resolves to the Response object representing the response to your request.

A fetch() promise only rejects when a network error is encountered (which is usually when there's a permissions issue or similar). A fetch() promise does not reject on HTTP errors (404, etc.). Instead, a then() handler must check the Response.ok and/or Response.status properties.

WindowOrWorkerGlobalScope is implemented by both Window and WorkerGlobalScope, which means that the fetch() method is available in pretty much any context in which you might want to fetch resources.

The fetch() method is controlled by the connect-src directive of Content Security Policy rather than the directive of the resources it's retrieving.

resource defines the resource that you wish to fetch. This can either be a string or any other object with a stringifier —including a URL object — that provides the URL of the resource you want to fetch. The URL may be relative to the base URL, which is the Document.baseURI in a window context, or WorkerGlobalScope.location in a worker context. A Request object.

Implementation

Future<Response> fetch(Object resource, [ RequestInit? options, ]) =>
  _fetch(
    switch (resource) {
      String() => resource.toJS,
      // A string or any other object with a stringifier.
      JSObject() when resource.isA<JSObject>() => resource,
      Object() => resource.toString().toJS,
    },
    options,
  ).toDart;