add EventSource interface

src/main/scala/org/scalajs/dom/lib.scala

@@ -6266,6 +6266,74 @@ object WebSocket extends js.Object {
  val CLOSED: Int = ???
 }
 
+/**
+ * EventSource enables servers to push data to Web pages over HTTP or using dedicated server-push protocols.
+ * Event streams requests can be redirected using HTTP 301 and 307 redirects as with normal HTTP requests.
+ * Clients will reconnect if the connection is closed; a client can be told to stop reconnecting using
+ * the HTTP 204 No Content response code.
+ * W3C 2012
+ * @param URL
+ * @param settings
+ */
+class EventSource(URL: String, settings: js.Dynamic = null) extends EventTarget {
+
+ /**
+ * The url attribute must return the absolute URL that resulted from resolving the value that
+ * was passed to the constructor.
+ * W3C 2012
+ * @return
+ */
+ def url: String = ???
+
+ /**
+ * The withCredentials attribute must return the value to which it was last initialized.
+ * When the object is created without withCredentials presents in the settings, it must be initialized to false.
+ * If it has the value true, then set CORS mode to Use Credentials and initialize the new EventSource
+ * object's withCredentials attribute.
+ * W3C 2012
+ */
+ def withCredentials: Boolean = ???
+
+ /**
+ * The readyState attribute represents the state of the connection.
+ * W3C 2012
+ */
+ def readyState: Int = ???
+
+ var onopen: js.Function1[Event, _] = ???
+
+ var onmessage: js.Function1[MessageEvent, _] = ???
+
+ var onerror: js.Function1[Event, _] = ???
+
+ /**
+ * The close() method must abort any instances of the fetch algorithm started for this EventSource object,
+ * and must set the readyState attribute to CLOSED.
+ * W3C 2012
+ */
+ def close(): Unit = ???
+
+}
+
+object EventSource extends js.Object {
+ /**
+ * The connection has not yet been established, or it was closed and the user agent is reconnecting.
+ * W3C 2012
+ */
+ val CONNECTING: Int = 0
+ /**
+ * The user agent has an open connection and is dispatching events as it receives them.
+ * W3C 2012
+ */
+ val OPEN: Int = 1
+ /**
+ * The connection is not open, and the user agent is not trying to reconnect. Either there was a fatal
+ * error or the close() method was invoked.
+ * W3C 2012
+ */
+ val CLOSED: Int = 2
+}
+
 /**
  * The ProgressEvent interface represents events measuring progress of an
  * underlying process, like an HTTP request (for an XMLHttpRequest, or the loading of