add redux middleware for paths

src/middleware/updateURLMiddleware.js

@@ -0,0 +1,47 @@
+const updateURLMiddleware = store => next => action => {
+  const oldState = store.getState();
+  const nextAction = next(action);
+
+  console.log('middleware', store, next, action)
+
+  if (action.type === 'url changed') {
+    return nextAction;
+  }
+
+  const state = store.getState();
+
+  // Internal helper for working with URIs
+  const oldURI = new URI(window.location.href);
+  const newURI = new URI(oldURI).setQueryData({});
+
+  newURI.setPath('/foo/bar');
+
+  // Set the path based on state
+  if (!state.isOnLandingPage && state.project.id) {
+    newURI.setPath(newURI.getPath() + state.project.id + '/');
+    newURI.addQueryData('baz', state.mode);
+    newURI.addQueryData('bat', state.selection.activePageID);
+  } else {
+    newURI.setPath(newURI.getPath() + state.landingSection + '/');
+  }
+
+  // Avoid URL thrashing by replacing state while loading instead of pushing
+  const newPath = newURI.toString();
+  const oldPath = oldURI.toString();
+  if (newPath !== oldPath) {
+    if (
+      (oldState.mode === 'asdf' &&
+        state.mode === 'asdf' &&
+        !oldState.isOnLandingPage) ||
+      oldState.isLoadingProject !== state.isLoadingProject
+    ) {
+      window.history.replaceState(null, null, newPath);
+    } else {
+      window.history.pushState(null, null, newPath);
+    }
+  }
+
+  return nextAction;
+};
+
+export default updateURLMiddleware;