refactor(routerId): add confirm message to notify user about alt router

Author: landonreed

Diff for: lib/actions/ui.js

@@ -77,7 +77,17 @@ export function matchContentToUrl (location) {
         // Update map location/zoom and optionally override router ID.
         dispatch(setMapCenter({ lat, lon }))
         dispatch(setMapZoom({ zoom }))
-        if (routerId) dispatch(setRouterId(routerId))
+        // If router ID is provided, override the default routerId.
+        if (routerId) {
+          // This is a somewhat hidden element of the trip planner, so show a
+          // confirmation message to the user to ensure they are aware of what
+          // is happening.
+          const useAltRouterId = window.confirm(
+            `The trip planner's router is set to ${routerId}.\n\nClick OK to confirm or Cancel to use the default router.\n\nNote: new sessions opened with URLs copied from this tab's address bar will not reference the correct router (must contain the #/start/lat/lon/zoom/router prefix).`
+          )
+          if (useAltRouterId) dispatch(setRouterId(routerId))
+          else dispatch(setRouterId(null))
+        }
         dispatch(setMainPanelContent(null))
         break
       // For any other route path, just revert to default panel.

Diff for: lib/reducers/create-otp-reducer.js

@@ -125,8 +125,12 @@ export function getInitialState (userDefinedConfig, initialQuery) {
   // This routerId session value is initially set by visiting otp-rr
   // with the path /start/:latLonZoomRouter, which dispatches the SET_ROUTER_ID
   // action and stores the value in sessionStorage.
+  // Note: this mechanism assumes that the OTP API path is otp/routers/default.
   const routerId = window.sessionStorage.getItem('routerId')
+  // If routerId is found, update the config.api.path (keep the original config
+  // value at _path in case it needs to be reverted.)
   if (routerId) {
+    config.api._path = userDefinedConfig.api.path
     config.api.path = `/otp/routers/${routerId}`
   }
   let queryModes = currentQuery.mode.split(',')
@@ -550,14 +554,23 @@ function createOtpReducer (config, initialQuery) {
           }
         })
       case 'SET_ROUTER_ID':
-        const routerId = action.payload || 'default'
+        const routerId = action.payload
+        // Store original path value in _path variable.
+        const _path = config.api._path || config.api.path || '/otp/routers/default'
+        const path = routerId
+          ? `/otp/routers/${routerId}`
+          // If routerId is null, revert to the original config's API path (or
+          // the standard path if that is not found).
+          : _path
         // Store routerId in session storage (persists through page reloads but
         // not when a new tab/window is opened).
-        window.sessionStorage.setItem('routerId', routerId)
+        if (routerId) window.sessionStorage.setItem('routerId', routerId)
+        else window.sessionStorage.removeItem('routerId')
         return update(state, {
           config: {
             api: {
-              path: { $set: `/otp/routers/${routerId}` }
+              path: { $set: path },
+              _path: { $set: _path }
             }
           }
         })