1 files changed, 80 insertions, 11 deletions

diff --git a/app/javascript/flavours/glitch/actions/markers.js b/app/javascript/flavours/glitch/actions/markers.js
index 7ffab404d..96e29accf 100644
--- a/app/javascript/flavours/glitch/actions/markers.js
+++ b/app/javascript/flavours/glitch/actions/markers.js
@@ -1,38 +1,107 @@
 import api from 'flavours/glitch/util/api';
+import { debounce } from 'lodash';
+import compareId from 'flavours/glitch/util/compare_id';
+import { showAlertForError } from './alerts';
 
 export const MARKERS_FETCH_REQUEST = 'MARKERS_FETCH_REQUEST';
 export const MARKERS_FETCH_SUCCESS = 'MARKERS_FETCH_SUCCESS';
 export const MARKERS_FETCH_FAIL    = 'MARKERS_FETCH_FAIL';
+export const MARKERS_SUBMIT_SUCCESS = 'MARKERS_SUBMIT_SUCCESS';
 
-export const submitMarkers = () => (dispatch, getState) => {
+export const synchronouslySubmitMarkers = () => (dispatch, getState) => {
   const accessToken = getState().getIn(['meta', 'access_token'], '');
-  const params      = {};
+  const params      = _buildParams(getState());
 
-  const lastHomeId         = getState().getIn(['timelines', 'home', 'items', 0]);
-  const lastNotificationId = getState().getIn(['notifications', 'lastReadId']);
+  if (Object.keys(params).length === 0) {
+    return;
+  }
+
+  // The Fetch API allows us to perform requests that will be carried out
+  // after the page closes. But that only works if the `keepalive` attribute
+  // is supported.
+  if (window.fetch && 'keepalive' in new Request('')) {
+    fetch('/api/v1/markers', {
+      keepalive: true,
+      method: 'POST',
+      headers: {
+        'Content-Type': 'application/json',
+        'Authorization': `Bearer ${accessToken}`,
+      },
+      body: JSON.stringify(params),
+    });
+    return;
+  } else if (navigator && navigator.sendBeacon) {
+    // Failing that, we can use sendBeacon, but we have to encode the data as
+    // FormData for DoorKeeper to recognize the token.
+    const formData = new FormData();
+    formData.append('bearer_token', accessToken);
+    for (const [id, value] of Object.entries(params)) {
+      formData.append(`${id}[last_read_id]`, value.last_read_id);
+    }
+    if (navigator.sendBeacon('/api/v1/markers', formData)) {
+      return;
+    }
+  }
+
+  // If neither Fetch nor sendBeacon worked, try to perform a synchronous
+  // request.
+  try {
+    const client = new XMLHttpRequest();
+
+    client.open('POST', '/api/v1/markers', false);
+    client.setRequestHeader('Content-Type', 'application/json');
+    client.setRequestHeader('Authorization', `Bearer ${accessToken}`);
+    client.SUBMIT(JSON.stringify(params));
+  } catch (e) {
+    // Do not make the BeforeUnload handler error out
+  }
+};
+
+const _buildParams = (state) => {
+  const params = {};
+
+  const lastHomeId         = state.getIn(['timelines', 'home', 'items', 0]);
+  const lastNotificationId = state.getIn(['notifications', 'lastReadId']);
 
-  if (lastHomeId) {
+  if (lastHomeId && compareId(lastHomeId, state.getIn(['markers', 'home'])) > 0) {
     params.home = {
       last_read_id: lastHomeId,
     };
   }
 
-  if (lastNotificationId && lastNotificationId !== '0') {
+  if (lastNotificationId && lastNotificationId !== '0' && compareId(lastNotificationId, state.getIn(['markers', 'notifications'])) > 0) {
     params.notifications = {
       last_read_id: lastNotificationId,
     };
   }
 
+  return params;
+};
+
+const debouncedSubmitMarkers = debounce((dispatch, getState) => {
+  const params = _buildParams(getState());
+
   if (Object.keys(params).length === 0) {
     return;
   }
 
-  const client = new XMLHttpRequest();
+  api().post('/api/v1/markers', params).then(() => {
+    dispatch(submitMarkersSuccess(params));
+  }).catch(error => {
+    dispatch(showAlertForError(error));
+  });
+}, 300000, { leading: true, trailing: true });
+
+export function submitMarkersSuccess({ home, notifications }) {
+  return {
+    type: MARKERS_SUBMIT_SUCCESS,
+    home: (home || {}).last_read_id,
+    notifications: (notifications || {}).last_read_id,
+  };
+};
 
-  client.open('POST', '/api/v1/markers', false);
-  client.setRequestHeader('Content-Type', 'application/json');
-  client.setRequestHeader('Authorization', `Bearer ${accessToken}`);
-  client.send(JSON.stringify(params));
+export function submitMarkers() {
+  return (dispatch, getState) => debouncedSubmitMarkers(dispatch, getState);
 };
 
 export const fetchMarkers = () => (dispatch, getState) => {