fix(Browser history): fixed NPE when navigating a study via browser history and history navigation is now available via the navigateHistory command

extensions/default/src/commandsModule.ts

@@ -11,6 +11,8 @@ import findViewportsByPosition, {
 } from './findViewportsByPosition';
 
 import { ContextMenuProps } from './CustomizeableContextMenu/types';
+import { NavigateHistory } from './types/commandModuleTypes';
+import { history } from '@ohif/viewer';
 
 const { subscribeToNextViewportGridChange } = utils;
 
@@ -480,6 +482,28 @@ const commandsModule = ({
       }
     },
 
+    /**
+     * Exposes the browser history navigation used by OHIF. This command can be used to either replace or
+     * push a new entry into the browser history. For example, the following will replace the current
+     * browser history entry with the specified relative URL which changes the study displayed to the
+     * study with study instance UID 1.2.3. Note that as a result of using `options.replace = true`, the
+     * page prior to invoking this command cannot be returned to via the browser back button.
+     *
+     * navigateHistory({
+     *   to: 'viewer?StudyInstanceUIDs=1.2.3',
+     *   options: { replace: true },
+     * });
+     *
+     * @param historyArgs - arguments for the history function;
+     *                      the `to` property is the URL;
+     *                      the `options.replace` is a boolean indicating if the current browser history entry
+     *                      should be replaced or a new entry pushed onto the history (stack); the default value
+     *                      for `replace` is false
+     */
+    navigateHistory(historyArgs: NavigateHistory) {
+      history.navigate(historyArgs.to, historyArgs.options);
+    },
+
     openDICOMTagViewer() {
       const { activeViewportIndex, viewports } = viewportGridService.getState();
       const activeViewportSpecificData = viewports[activeViewportIndex];
@@ -540,6 +564,11 @@ const commandsModule = ({
       storeContexts: [],
       options: {},
     },
+    navigateHistory: {
+      commandFn: actions.navigateHistory,
+      storeContexts: [],
+      options: {},
+    },
     nextStage: {
       commandFn: actions.deltaStage,
       storeContexts: [],

extensions/default/src/types/commandModuleTypes.tsx

@@ -0,0 +1,6 @@
+export type NavigateHistory = {
+  to: string; // the URL to navigate to
+  options?: {
+    replace?: boolean; // replace or add/push to history?
+  };
+};

extensions/measurement-tracking/src/contexts/TrackedMeasurementsContext/TrackedMeasurementsContext.tsx

@@ -149,6 +149,10 @@ function TrackedMeasurementsContextProvider(
         activeViewport.displaySetInstanceUIDs[0]
       );
 
+      if (!displaySet) {
+        return;
+      }
+
       // If this is an SR produced by our SR SOPClassHandler,
       // and it hasn't been loaded yet, do that now so we
       // can check if it can be rehydrated or not.

platform/docs/docs/platform/modes/routes.md

@@ -313,3 +313,34 @@ function modeFactory() {
   };
 }
 ```
+
+> How can I navigate to (or show) a different study via the browser history/URL?
+
+There is a command that does this: `navigateHistory`. It takes an object
+argument with the `NavigateHistory` type:
+
+```
+export type NavigateHistory = {
+  to: string; // the URL to navigate to
+  options?: {
+    replace?: boolean; // replace or add/push to history?
+  };
+};
+```
+
+For instance one could bind a hot key to this command to show a specific study
+like this...
+
+```
+  {
+    commandName: 'navigateHistory',
+    commandOptions: {
+      to:
+        '/viewer?StudyInstanceUIDs=1.2.3',
+    },
+    context: 'DEFAULT',
+    label: 'Nav Study',
+    keys: ['n'],
+    isEditable: true,
+  },
+```

platform/viewer/src/index.js

@@ -5,6 +5,8 @@ import 'regenerator-runtime/runtime';
 import App from './App';
 import React from 'react';
 import ReactDOM from 'react-dom';
+import { history } from './utils/history';
+
 /**
  * EXTENSIONS AND MODES
  * =================
@@ -34,3 +36,5 @@ loadDynamicImports().then(() => {
     ReactDOM.render(app, document.getElementById('root'));
   });
 });
+
+export { history };

platform/viewer/src/routes/Mode/Mode.tsx

@@ -1,5 +1,5 @@
 import React, { useEffect, useState, useRef } from 'react';
-import { useParams, useLocation } from 'react-router';
+import { useParams, useLocation, useNavigate } from 'react-router';
 import PropTypes from 'prop-types';
 // TODO: DicomMetadataStore should be injected?
 import { DicomMetadataStore, ServicesManager, utils } from '@ohif/core';
@@ -8,6 +8,7 @@ import { useQuery, useSearchParams } from '@hooks';
 import ViewportGrid from '@components/ViewportGrid';
 import Compose from './Compose';
 import getStudies from './studiesList';
+import { history } from '../../utils/history';
 
 const { getSplitParam } = utils;
 
@@ -105,6 +106,9 @@ export default function ModeRoute({
   const locationRef = useRef(null);
   const isMounted = useRef(false);
 
+  // Expose the react router dom navigation.
+  history.navigate = useNavigate();
+
   if (location !== locationRef.current) {
     layoutTemplateData.current = null;
     locationRef.current = location;

platform/viewer/src/utils/history.ts

@@ -0,0 +1,9 @@
+import { NavigateFunction } from 'react-router';
+
+type History = {
+  navigate: NavigateFunction;
+};
+
+export const history: History = {
+  navigate: null,
+};