Connections

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👩‍🔬 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.

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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