From 06c1a8f71d04112d8925cb7e35b48a2a228722cd Mon Sep 17 00:00:00 2001
From: Max Lynch <max@ionic.io>
Date: Thu, 24 Dec 2020 15:56:08 -0600
Subject: [PATCH] Refactor state and make list detail a page

---
 README.md                       |  1 +
 components/MenuContent.jsx      | 25 ++++++++------
 components/pages/Home.jsx       |  5 +--
 components/pages/ListDetail.jsx | 60 ++++++++++++++++++++++++++++++++
 components/pages/Lists.jsx      | 61 +++++----------------------------
 components/ui/Nav.jsx           | 24 +++++--------
 package-lock.json               |  6 ++++
 package.json                    |  3 +-
 pages/index.js                  | 47 +++++++++----------------
 store/actions.js                | 32 +++++++++++++++++
 store/index.js                  | 18 ++++++++--
 store/selectors.js              | 15 ++++++++
 12 files changed, 182 insertions(+), 115 deletions(-)
 create mode 100644 components/pages/ListDetail.jsx
 create mode 100644 store/selectors.js

diff --git a/README.md b/README.md
index 34eee74..982a457 100644
--- a/README.md
+++ b/README.md
@@ -24,6 +24,7 @@ There are currently snippets for the following common mobile components:
 - [x] Content
 - [x] Tabs
 - [ ] Nav (in progress)
+- [ ] Next.js router integration
 - [x] Icon
 - [x] Menu
 - [x] Modal
diff --git a/components/MenuContent.jsx b/components/MenuContent.jsx
index 050d216..08f06c6 100644
--- a/components/MenuContent.jsx
+++ b/components/MenuContent.jsx
@@ -1,4 +1,6 @@
 import Store from '../store';
+import * as actions from '../store/actions';
+import * as selectors from '../store/selectors';
 
 const MenuItem = ({ children, ...props }) => (
   <li {...props}>
@@ -12,14 +14,11 @@ const MenuItem = ({ children, ...props }) => (
 );
 
 const MenuContent = () => {
-  const pages = Store.useState(s => s.pages);
+  const menuLinks = Store.useState(selectors.getMenuLinks);
 
   const go = page => {
-    Store.update(s => {
-      console.log('Going to', page);
-      s.currentPage = page;
-      s.showMenu = false;
-    });
+    actions.setPage(page);
+    actions.setMenuOpen(false);
   };
 
   return (
@@ -28,11 +27,15 @@ const MenuContent = () => {
         <h2 className="text-xl select-none">Menu</h2>
       </div>
       <ul>
-        {pages.map(p => (
-          <MenuItem key={p.id} onClick={() => go(p)}>
-            {p.title}
-          </MenuItem>
-        ))}
+        {menuLinks.map(p => {
+          const title = typeof p.title === 'function' ? p.title() : p.title;
+
+          return (
+            <MenuItem key={p.id} onClick={() => go(p)}>
+              {title}
+            </MenuItem>
+          );
+        })}
       </ul>
     </>
   );
diff --git a/components/pages/Home.jsx b/components/pages/Home.jsx
index a0f2603..31d2749 100644
--- a/components/pages/Home.jsx
+++ b/components/pages/Home.jsx
@@ -1,8 +1,9 @@
-import { homeItems } from '../../data';
 import Store from '../../store';
 import Card from '../ui/Card';
 import Content from '../ui/Content';
 
+import * as selectors from '../../store/selectors';
+
 const HomeCard = ({ title, type, text, author, image }) => (
   <Card className="my-4">
     <div>
@@ -17,7 +18,7 @@ const HomeCard = ({ title, type, text, author, image }) => (
 );
 
 const Home = ({ selected }) => {
-  const homeItems = Store.useState(s => s.homeItems);
+  const homeItems = Store.useState(selectors.getHomeItems);
 
   return (
     <Content visible={selected} className="p-4">
diff --git a/components/pages/ListDetail.jsx b/components/pages/ListDetail.jsx
new file mode 100644
index 0000000..54e597b
--- /dev/null
+++ b/components/pages/ListDetail.jsx
@@ -0,0 +1,60 @@
+import Store from '../../store';
+import * as actions from '../../store/actions';
+import * as selectors from '../../store/selectors';
+
+import Content from '../ui/Content';
+import List from '../ui/List';
+import VirtualScroll from '../ui/VirtualScroll';
+
+const ListItems = ({ list, onClose }) => {
+  return (
+    <>
+      <div className="py-2">
+        <a href="#" onClick={onClose}>
+          All Lists
+        </a>
+      </div>
+      <VirtualScroll
+        data={list?.items || []}
+        totalCount={(list?.items || []).length}
+        style={{ height: '100%', width: '100%' }}
+        itemContent={(i, item) => <ListItemEntry list={list} item={item} />}
+      />
+    </>
+  );
+};
+
+const ListItemEntry = ({ list, item }) => (
+  <div className="p-4 border-solid border-b cursor-pointer">
+    <span className="text-md">{item.name}</span>
+    <input
+      type="checkbox"
+      checked={item.done}
+      onChange={() => {
+        actions.setDone(list, item, !item.done);
+      }}
+    />
+  </div>
+);
+
+const ListDetail = ({ selected }) => {
+  const selectedList = Store.useState(selectors.getSelectedList);
+
+  return (
+    <Content visible={selected} className="p-4">
+      <List className="h-full w-full">
+        {selected && (
+          <ListItems
+            list={selectedList}
+            onClose={() => {
+              actions.setSelectedList(null);
+              actions.setPageById('lists');
+            }}
+          />
+        )}
+      </List>
+    </Content>
+  );
+};
+
+export default ListDetail;
diff --git a/components/pages/Lists.jsx b/components/pages/Lists.jsx
index 6f9237d..42d92fb 100644
--- a/components/pages/Lists.jsx
+++ b/components/pages/Lists.jsx
@@ -1,11 +1,9 @@
-import { useState } from 'react';
 import Store from '../../store';
-import { setDone } from '../../store/actions';
-import Card from '../ui/Card';
+import * as actions from '../../store/actions';
+import * as selectors from '../../store/selectors';
 
 import Content from '../ui/Content';
 import List from '../ui/List';
-import ListItem from '../ui/ListItem';
 import VirtualScroll from '../ui/VirtualScroll';
 
 const ListEntry = ({ list, ...props }) => (
@@ -15,7 +13,7 @@ const ListEntry = ({ list, ...props }) => (
 );
 
 const AllLists = ({ onSelect }) => {
-  const lists = Store.useState(s => s.lists);
+  const lists = Store.useState(selectors.getLists);
 
   return (
     <VirtualScroll
@@ -29,58 +27,15 @@ const AllLists = ({ onSelect }) => {
   );
 };
 
-const ListItems = ({ list, onClose }) => {
-  return (
-    <>
-      <div className="py-2">
-        <a href="#" onClick={onClose}>
-          All Lists
-        </a>
-      </div>
-      <VirtualScroll
-        data={list.items || []}
-        totalCount={(list.items || []).length}
-        style={{ height: '100%', width: '100%' }}
-        itemContent={(i, item) => <ListItemEntry list={list} item={item} />}
-      />
-    </>
-  );
-};
-
-const ListItemEntry = ({ list, item }) => (
-  <div className="p-4 border-solid border-b cursor-pointer">
-    <span className="text-md">{item.name}</span>
-    <input
-      type="checkbox"
-      checked={item.done}
-      onChange={() => {
-        setDone(list, item, !item.done);
-      }}
-    />
-  </div>
-);
-
-const Feed = ({ selected }) => {
-  const selectedList = Store.useState(s => s.selectedList);
-
+const Lists = ({ selected }) => {
   return (
     <Content visible={selected} className="p-4">
       <List className="h-full w-full">
-        {selected && selectedList ? (
-          <ListItems
-            list={selectedList}
-            onClose={() =>
-              Store.update(s => {
-                s.selectedList = null;
-              })
-            }
-          />
-        ) : (
+        {selected && (
           <AllLists
             onSelect={list => {
-              Store.update(s => {
-                s.selectedList = list;
-              });
+              actions.setSelectedList(list);
+              actions.setPageById('list-detail');
             }}
           />
         )}
@@ -89,4 +44,4 @@ const Feed = ({ selected }) => {
   );
 };
 
-export default Feed;
+export default Lists;
diff --git a/components/ui/Nav.jsx b/components/ui/Nav.jsx
index e43d155..d960f6c 100644
--- a/components/ui/Nav.jsx
+++ b/components/ui/Nav.jsx
@@ -1,10 +1,12 @@
 import { useEffect, useState } from 'react';
 
 import { Plugins } from '@capacitor/core';
-import Store from '../../store';
+import * as actions from '../../store/actions';
 
 const Nav = ({ page }) => {
-  const [showMenu, setShowMenu] = useState(false);
+  const [showProfileMenu, setShowProfileMenu] = useState(false);
+
+  const title = typeof page.title === 'function' ? page.title() : page.title;
 
   useEffect(() => {
     Plugins.StatusBar.setStyle({
@@ -23,11 +25,7 @@ const Nav = ({ page }) => {
         <div className="relative flex items-center justify-between h-16">
           <div
             className="absolute inset-y-0 left-0 flex items-center sm:hidden"
-            onClick={() =>
-              Store.update(s => {
-                s.showMenu = true;
-              })
-            }
+            onClick={() => actions.setMenuOpen(true)}
           >
             {/* Mobile menu button*/}
             <button
@@ -81,7 +79,7 @@ const Nav = ({ page }) => {
           </div>
           <div className="flex-1 flex items-center justify-center sm:items-stretch sm:justify-start">
             <div className="flex-shrink-0 flex items-center">
-              <h1 className="text-gray-50">{page.title}</h1>
+              <h1 className="text-gray-50">{title}</h1>
             </div>
             <div className="hidden sm:block sm:ml-6">
               <div className="flex space-x-4">
@@ -116,11 +114,7 @@ const Nav = ({ page }) => {
           <div className="absolute inset-y-0 right-0 flex items-center pr-2 sm:static sm:inset-auto sm:ml-6 sm:pr-0">
             <button
               className="bg-gray-800 p-1 rounded-full text-gray-400 hover:text-white focus:outline-none focus:ring-2 focus:ring-offset-2 focus:ring-offset-gray-800 focus:ring-white"
-              onClick={() =>
-                Store.update(s => {
-                  s.showNotifications = true;
-                })
-              }
+              onClick={() => actions.setNotificationsOpen(true)}
             >
               <span className="sr-only">View notifications</span>
               {/* Heroicon name: bell */}
@@ -148,7 +142,7 @@ const Nav = ({ page }) => {
                   className="bg-gray-800 flex text-sm rounded-full focus:outline-none focus:ring-2 focus:ring-offset-2 focus:ring-offset-gray-800 focus:ring-white"
                   id="user-menu"
                   aria-haspopup="true"
-                  onClick={() => setShowMenu(!showMenu)}
+                  onClick={() => setShowProfileMenu(!showProfileMenu)}
                 >
                   <span className="sr-only">Open user menu</span>
                   <img
@@ -170,7 +164,7 @@ const Nav = ({ page }) => {
         */}
               <div
                 className={`${
-                  showMenu ? '' : 'hidden'
+                  showProfileMenu ? '' : 'hidden'
                 } origin-top-right absolute right-0 mt-2 w-48 rounded-md shadow-lg py-1 bg-white ring-1 ring-black ring-opacity-5`}
                 role="menu"
                 aria-orientation="vertical"
diff --git a/package-lock.json b/package-lock.json
index e98917f..4230734 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -4497,6 +4497,12 @@
       "resolved": "https://registry.npmjs.org/repeat-string/-/repeat-string-1.6.1.tgz",
       "integrity": "sha1-jcrkcOHIirwtYA//Sndihtp15jc="
     },
+    "reselect": {
+      "version": "4.0.0",
+      "resolved": "https://registry.npmjs.org/reselect/-/reselect-4.0.0.tgz",
+      "integrity": "sha512-qUgANli03jjAyGlnbYVAV5vvnOmJnODyABz51RdBN7M4WaVu8mecZWgyQNkG8Yqe3KRGRt0l4K4B3XVEULC4CA==",
+      "dev": true
+    },
     "resize-observer-polyfill": {
       "version": "1.5.1",
       "resolved": "https://registry.npmjs.org/resize-observer-polyfill/-/resize-observer-polyfill-1.5.1.tgz",
diff --git a/package.json b/package.json
index 421b1b1..b102c93 100644
--- a/package.json
+++ b/package.json
@@ -26,6 +26,7 @@
     "prettier": "^2.2.1",
     "pullstate": "^1.20.5",
     "react-spring": "^8.0.27",
-    "react-use-gesture": "^9.0.0-beta.11"
+    "react-use-gesture": "^9.0.0-beta.11",
+    "reselect": "^4.0.0"
   }
 }
diff --git a/pages/index.js b/pages/index.js
index e4fb5f4..02df96b 100644
--- a/pages/index.js
+++ b/pages/index.js
@@ -1,4 +1,8 @@
+import { useDrag } from 'react-use-gesture';
+
 import Store from '../store';
+import * as actions from '../store/actions';
+import * as selectors from '../store/selectors';
 
 import App from '../components/ui/App';
 import Backdrop from '../components/ui/Backdrop';
@@ -9,14 +13,11 @@ import PageStack from '../components/ui/PageStack';
 import Tab from '../components/ui/Tab';
 import TabBar from '../components/ui/TabBar';
 import { SafeAreaProvider } from '../components/ui/SafeArea';
-
-import { useDrag } from 'react-use-gesture';
-
 import Notifications from '../components/Notifications';
 import MenuContent from '../components/MenuContent';
 
 const CurrentPage = ({ page }) => {
-  const pages = Store.useState(s => s.pages);
+  const pages = Store.useState(selectors.getPages);
 
   return (
     <PageStack>
@@ -29,37 +30,25 @@ const CurrentPage = ({ page }) => {
 };
 
 export default function Index() {
-  const showMenu = Store.useState(s => s.showMenu);
-  const showNotifications = Store.useState(s => s.showNotifications);
-  const currentPage = Store.useState(s => s.currentPage);
-  const pages = Store.useState(s => s.pages);
+  const showMenu = Store.useState(selectors.getMenuOpen);
+  const showNotifications = Store.useState(selectors.getNotificationsOpen);
+  const currentPage = Store.useState(selectors.getCurrentPage);
+  const tabs = Store.useState(selectors.getTabs);
 
-  const closeMenu = () => {
-    Store.update(s => {
-      s.showMenu = false;
-    });
-  };
+  const closeMenu = () => actions.setMenuOpen(false);
 
   const backdropClose = () => {
-    Store.update(s => {
-      s.showMenu = false;
-      s.showNotifications = false;
-    });
+    actions.setMenuOpen(false);
+    actions.setNotificationsOpen(false);
   };
 
-  const closeNotifications = () => {
-    Store.update(s => {
-      s.showNotifications = false;
-    });
-  };
+  const closeNotifications = () => actions.setNotificationsOpen(false);
 
   // To enable edge drag detection to open the side menu
   const bind = useDrag(
     ({ down, movement: [mx], xy: [x, y], cancel }) => {
       if (mx > 5 && x < 50 && down) {
-        Store.update(s => {
-          s.showMenu = true;
-        });
+        actions.setMenuOpen(true);
         cancel();
       }
     },
@@ -84,15 +73,11 @@ export default function Index() {
         <Nav page={currentPage} />
         <CurrentPage page={currentPage} />
         <TabBar>
-          {pages.map(p => (
+          {tabs.map(p => (
             <Tab
               key={p.id}
               {...p}
-              onClick={() =>
-                Store.update(s => {
-                  s.currentPage = p;
-                })
-              }
+              onClick={() => actions.setPage(p)}
               selected={p.id === currentPage.id}
             />
           ))}
diff --git a/store/actions.js b/store/actions.js
index 080516d..05f2f10 100644
--- a/store/actions.js
+++ b/store/actions.js
@@ -1,5 +1,31 @@
 import Store from '.';
 
+export const setPageById = id => {
+  Store.update((s, o) => {
+    s.currentPage = o.pages.find(p => p.id === id);
+  });
+};
+
+export const setPage = page => {
+  Store.update((s, o) => {
+    s.currentPage = page;
+  });
+};
+
+export const setMenuOpen = open => {
+  Store.update(s => {
+    s.menuOpen = open;
+  });
+};
+
+export const setNotificationsOpen = open => {
+  Store.update(s => {
+    s.notificationsOpen = open;
+  });
+};
+
+// App-specific actions
+
 export const setDone = (list, item, done) => {
   Store.update((s, o) => {
     const listIndex = o.lists.findIndex(l => l === list);
@@ -10,3 +36,9 @@ export const setDone = (list, item, done) => {
     }
   });
 };
+
+export const setSelectedList = list => {
+  Store.update(s => {
+    s.selectedList = list;
+  });
+};
diff --git a/store/index.js b/store/index.js
index 563d930..eb3efcf 100644
--- a/store/index.js
+++ b/store/index.js
@@ -5,6 +5,7 @@ import { list, listOutline, cog, cogOutline, home, homeOutline } from 'ionicons/
 import Home from '../components/pages/Home';
 import Lists from '../components/pages/Lists';
 import Settings from '../components/pages/Settings';
+import ListDetail from '../components/pages/ListDetail';
 
 // The available pages here
 const pages = [
@@ -16,6 +17,13 @@ const pages = [
     selectedIcon: list,
     component: Lists,
   },
+  {
+    id: 'list-detail',
+    title: () => Store.getRawState().selectedList?.name,
+    icon: listOutline,
+    selectedIcon: list,
+    component: ListDetail,
+  },
   {
     id: 'settings',
     title: 'Settings',
@@ -81,10 +89,16 @@ const lists = [
 const Store = new PullStateStore({
   safeAreaTop: 0,
   safeAreaBottom: 0,
-  showMenu: false,
-  showNotifications: false,
+  menuOpen: false,
+  notificationsOpen: false,
   currentPage: pages[0],
   pages,
+
+  // The pages that are linked to tabs
+  tabs: pages.filter(p => ['home', 'lists', 'settings'].indexOf(p.id) >= 0),
+  // The pages that are linked to the menu
+  menuLinks: pages.filter(p => ['home', 'lists', 'settings'].indexOf(p.id) >= 0),
+
   homeItems,
   lists,
   selectedList: null,
diff --git a/store/selectors.js b/store/selectors.js
new file mode 100644
index 0000000..1ef2bee
--- /dev/null
+++ b/store/selectors.js
@@ -0,0 +1,15 @@
+import { createSelector } from 'reselect';
+
+const getState = state => state;
+
+export const getMenuOpen = createSelector(getState, state => state.menuOpen);
+export const getNotificationsOpen = createSelector(getState, state => state.notificationsOpen);
+export const getCurrentPage = createSelector(getState, state => state.currentPage);
+export const getTabs = createSelector(getState, state => state.tabs);
+export const getMenuLinks = createSelector(getState, state => state.menuLinks);
+export const getPages = createSelector(getState, state => state.pages);
+
+// App specific selectors
+export const getHomeItems = createSelector(getState, state => state.homeItems);
+export const getLists = createSelector(getState, state => state.lists);
+export const getSelectedList = createSelector(getState, state => state.selectedList);