Indicator of the current state of the request:
| Value | State | Meaning |
| 0 | unsent | open() has not yet been called |
| 1 | opened | send() has not yet been called |
| 2 | headers received | sent() has been called; response headers and status are available |
| 3 | loading | responseText holds some data |
| 4 | done | request is complete |
Source
@DomName('XMLHttpRequest.readyState')
@DocsEditable()
int get readyState => _blink.BlinkXMLHttpRequest.instance.readyState_Getter_(this);