1 files changed, 51 insertions, 0 deletions
diff --git a/common/js/src/main/scala/http/XhrBackend.scala b/common/js/src/main/scala/http/XhrBackend.scala
new file mode 100644
index 0000000..3a791c1
--- /dev/null
+++ b/common/js/src/main/scala/http/XhrBackend.scala
@@ -0,0 +1,51 @@
+package triad
+package http
+
+import org.scalajs.dom.{ErrorEvent, Event, XMLHttpRequest}
+
+import scala.concurrent.{Future, Promise, TimeoutException}
+import scala.scalajs.js
+import scala.scalajs.js.typedarray.{ArrayBuffer, Int8Array}
+
+trait XhrBackend extends Backend {
+
+  def send(request: Request): Future[Response] = {
+    val promise = Promise[Response]
+    val xhr = new XMLHttpRequest()
+
+    xhr.open(request.method, request.url)
+    xhr.responseType = "arraybuffer"
+    for ((name, value) <- request.headers) {
+      xhr.setRequestHeader(name, value)
+    }
+
+    xhr.send(js.Array(request.body: _*))
+
+    xhr.onload = (e: Event) => {
+      val body: Array[Byte] = if (!js.isUndefined(xhr.response)) {
+        val buffer = new Int8Array(xhr.response.asInstanceOf[ArrayBuffer])
+        buffer.toArray
+      } else {
+        Array.empty[Byte]
+      }
+
+      val response = Response(
+        xhr.status,
+        Map.empty,
+        body
+      )
+      promise.success(response)
+    }
+
+    xhr.onerror = (e: ErrorEvent) => {
+      promise.failure(new RuntimeException(s"XHR error: ${e.message}"))
+    }
+    xhr.ontimeout = (e: Event) => {
+      promise.failure(
+        new TimeoutException(s"Request timed out: ${xhr.statusText}"))
+    }
+
+    promise.future
+  }
+
+}