Connections

👩‍🔬 Please be aware that this package is still experimental — changes to the interface and underlying implementation are likely, and future development or maintenance is not guaranteed.

This package provides different connection types with a unified interface.

Example

The following example will create an XHRConnection, add a complete event listener and open the connection. The complete listener will get called once the JSON file is loaded and the connection is closed.

import { XHRConnection, ConnectionEvent } from "@dcos/connections";

const connection = new XHRConnection("http://example.com/file.json");
connection.addListener(ConnectionEvent.COMPLETE, (event) => console.log(event));
connection.open();

Abstract Connection

The AbstractConnection provides the default properties, methods, states, and event-definitions to implement a custom connection.

Connection Event

The ConnectionEvent provides a common interface for all different event types.

Types

Use the following event types...

• OPEN when opening the connection
• DATA every time data is received from the server
• ERROR when an error occurred
• COMPLETE when the connection closes without any errors
• ABORT when the connection was aborted by something

Target

The event target always points to the connection.

XHR Connection

The XHRConnection wraps the native XMLHttpRequest to provide a unified and easy to use interface.

Example

The following example will create an XHRConnection to post "data" to an API server.

const connection = new XHRConnection("http://example.com/api", {
  method: "POST",
  body: "data"
});
connection.open();

Parameters

URL

This defines the resource location that you want to connect to.

Options (Optional)

An optional object containing custom settings that you want to apply to the connection.

• headers: Any headers you want to add to your request
• method: The request method (default: "GET")
• body: Any data you want send with your request
• responseType: The response type you expect (default: "json") If the server returns data that is not compatible the value of response will be null.

Response Types

Value | Data type of response property -- | -- "arraybuffer" | ArrayBuffer "blob" | Blob "document" | Document "json" | JavaScript object, parsed from a JSON string returned by the server "text" | DOMString