feat: 🎸 Allow routes to load Google Cloud DICOM Stores in the Study List (#1069)

platform/viewer/src/customHooks/usePrevious.js

@@ -0,0 +1,9 @@
+import React, { useEffect, useRef } from 'react';
+export default function usePrevious(value) {
+  const ref = useRef();
+  useEffect(() => {
+    ref.current = value;
+  }, [value]);
+
+  return ref.current;
+}

platform/viewer/src/customHooks/useServer.js

@@ -1,8 +1,10 @@
 import React, { useContext } from 'react';
 import GoogleCloudApi from '../googleCloud/api/GoogleCloudApi';
+import usePrevious from './usePrevious';
 
 import * as GoogleCloudUtilServers from '../googleCloud/utils/getServers';
 import { useSelector, useDispatch } from 'react-redux';
+import isEqual from 'lodash.isequal';
 
 // Contexts
 import AppContext from '../context/AppContext';
@@ -32,28 +34,68 @@ const getServers = (appConfig, project, location, dataset, dicomStore) => {
       wadoRoot: pathUrl,
     };
     servers = GoogleCloudUtilServers.getServers(data, dicomStore);
+    if (!isValidServer(servers[0], appConfig)) {
+      return;
+    }
   }
 
   return servers;
 };
 
-const updateServer = (
+const isValidServer = (server, appConfig) => {
+  if (appConfig.enableGoogleCloudAdapter) {
+    return GoogleCloudUtilServers.isValidServer(server);
+  }
+
+  return !!server;
+};
+
+const setServers = (dispatch, servers) => {
+  const action = {
+    type: 'SET_SERVERS',
+    servers,
+  };
+  dispatch(action);
+};
+
+const useServerFromUrl = (
+  servers = [],
+  previousServers,
+  activeServer,
+  urlBasedServers,
   appConfig,
-  dispatch,
   project,
   location,
   dataset,
   dicomStore
 ) => {
-  const servers = getServers(appConfig, project, location, dataset, dicomStore);
-
-  if (servers && servers.length) {
-    const action = {
-      type: 'SET_SERVERS',
-      servers,
-    };
-    dispatch(action);
+  // update state from url available only when gcloud on
+  if (!appConfig.enableGoogleCloudAdapter) {
+    return false;
   }
+
+  const serverHasChanged = previousServers !== servers && previousServers;
+
+  // do not update from url. use state instead.
+  if (serverHasChanged) {
+    return false;
+  }
+
+  // if no valid urlbased servers
+  if (!urlBasedServers || !urlBasedServers.length) {
+    return false;
+  } else if (!servers.length || !activeServer) {
+    // no current valid server
+    return true;
+  }
+
+  const newServer = urlBasedServers[0];
+
+  let exists = servers.some(
+    GoogleCloudUtilServers.isEqualServer.bind(undefined, newServer)
+  );
+
+  return !exists;
 };
 
 export default function useServer({
@@ -64,14 +106,29 @@ export default function useServer({
 } = {}) {
   // Hooks
   const servers = useSelector(state => state && state.servers);
+  const previousServers = usePrevious(servers);
   const dispatch = useDispatch();
+
   const { appConfig = {} } = useContext(AppContext);
 
-  const server = getActiveServer(servers);
+  const activeServer = getActiveServer(servers);
+  const urlBasedServers =
+    getServers(appConfig, project, location, dataset, dicomStore) || [];
+  const shouldUpdateServer = useServerFromUrl(
+    servers.servers,
+    previousServers,
+    activeServer,
+    urlBasedServers,
+    appConfig,
+    project,
+    location,
+    dataset,
+    dicomStore
+  );
 
-  if (!server) {
-    updateServer(appConfig, dispatch, project, location, dataset, dicomStore);
-  } else {
-    return server;
+  if (shouldUpdateServer) {
+    setServers(dispatch, urlBasedServers);
+  } else if (isValidServer(activeServer, appConfig)) {
+    return activeServer;
   }
 }