update code style

src/content/en/ilt/pwa/lab-indexeddb.md

@@ -178,10 +178,10 @@ Add some sample furniture items to the object store.
 Replace TODO 3.3 in `main.js` with the following code:
 
 ```
-dbPromise.then(function(db) {
- var tx = db.transaction('products', 'readwrite');
- var store = tx.objectStore('products');
- var items = [
+dbPromise.then((db) => {
+ const tx = db.transaction('products', 'readwrite');
+ const store = tx.objectStore('products');
+ const items = [
  {
  name: 'Couch',
  id: 'cch-blk-ma',
@@ -237,14 +237,14 @@ dbPromise.then(function(db) {
  quantity: 11
  }
  ];
- return Promise.all(items.map(function(item) {
+ return Promise.all(items.map((item) => {
  console.log('Adding item: ', item);
  return store.add(item);
  })
- ).catch(function(e) {
+ ).catch((e) => {
  tx.abort();
  console.log(e);
- }).then(function() {
+ }).then(() => {
  console.log('All items added successfully!');
  });
 });
@@ -286,14 +286,14 @@ Replace TODO 4.1 in `main.js` with the following code:
 ```
 case 2:
  console.log('Creating a name index');
- var store = upgradeDb.transaction.objectStore('products');
+ const store = upgradeDb.transaction.objectStore('products');
  store.createIndex('name', 'name', {unique: true});
 ```
 
 Change the version number to 3 in the call to `idb.open`. The full `idb.open` method should look like this:
 
 ```
-var dbPromise = idb.open('couches-n-things', 3, function(upgradeDb) {
+const dbPromise = idb.open('couches-n-things', 3, (upgradeDb) => {
  switch (upgradeDb.oldVersion) {
  case 0:
  // a placeholder case so that the switch block will
@@ -304,7 +304,7 @@ var dbPromise = idb.open('couches-n-things', 3, function(upgradeDb) {
  upgradeDb.createObjectStore('products', {keyPath: 'id'});
  case 2:
  console.log('Creating a name index');
- var store = upgradeDb.transaction.objectStore('products');
+ const store = upgradeDb.transaction.objectStore('products');
  store.createIndex('name', 'name', {unique: true});
 
  // TODO 4.2 - create 'price' and 'description' indexes
@@ -343,10 +343,10 @@ Use the indexes you created in the previous sections to retrieve items from the
 Add the following code to the `getByName` function in `main.js`:
 
 ```
-return dbPromise.then(function(db) {
- var tx = db.transaction('products', 'readonly');
- var store = tx.objectStore('products');
- var index = store.index('name');
+return dbPromise.then((db) => {
+ const tx = db.transaction('products', 'readonly');
+ const store = tx.objectStore('products');
+ const index = store.index('name');
  return index.get(key);
 });
 ```
@@ -376,37 +376,37 @@ Use a cursor object to get items from your store within a price range.
 Replace TODO 4.4a in `main.js` with the following code:
 
 ```
-var lower = document.getElementById('priceLower').value;
-var upper = document.getElementById('priceUpper').value;
-var lowerNum = Number(document.getElementById('priceLower').value);
-var upperNum = Number(document.getElementById('priceUpper').value);
+const lower = document.getElementById('priceLower').value;
+const upper = document.getElementById('priceUpper').value;
+const lowerNum = Number(document.getElementById('priceLower').value);
+const upperNum = Number(document.getElementById('priceUpper').value);
 
 if (lower === '' && upper === '') {return;}
-var range;
+let range;
 if (lower !== '' && upper !== '') {
  range = IDBKeyRange.bound(lowerNum, upperNum);
 } else if (lower === '') {
  range = IDBKeyRange.upperBound(upperNum);
 } else {
  range = IDBKeyRange.lowerBound(lowerNum);
 }
-var s = '';
-dbPromise.then(function(db) {
- var tx = db.transaction('products', 'readonly');
- var store = tx.objectStore('products');
- var index = store.index('price');
+let s = '';
+dbPromise.then((db) => {
+ const tx = db.transaction('products', 'readonly');
+ const store = tx.objectStore('products');
+ const index = store.index('price');
  return index.openCursor(range);
 }).then(function showRange(cursor) {
- if (!cursor) {return;}
+ if (!cursor) return;
  console.log('Cursored at:', cursor.value.name);
  s += '<h2>Price - ' + cursor.value.price + '</h2><p>';
- for (var field in cursor.value) {
+ for (const field in cursor.value) {
  s += field + '=' + cursor.value[field] + '<br/>';
  }
  s += '</p>';
  return cursor.continue().then(showRange);
-}).then(function() {
- if (s === '') {s = '<p>No results.</p>';}
+}).then(() => {
+ if (s === '') s = '<p>No results.</p>';
  document.getElementById('results').innerHTML = s;
 });
 ```
@@ -454,7 +454,7 @@ Open the test page. Your app should pass the next test which tests if the `order
 This step is for you to complete on your own. In the `addOrders` function in `main.js`, write the code to add the following items to the `orders` object store. This code will be very similar to the `addProducts` function that we wrote at the start of the lab:
 
 ```
-var items = [
+const items = [
  {
  name: 'Cabinet',
  id: 'ca-brn-ma',
@@ -510,12 +510,12 @@ This step processes the array of orders passed to the `processOrders` function.
 Replace TODO 5.5 in `main.js` with the following code:
 
 ```
-return dbPromise.then(function(db) {
- var tx = db.transaction('products');
- var store = tx.objectStore('products');
+return dbPromise.then((db) => {
+ const tx = db.transaction('products');
+ const store = tx.objectStore('products');
  return Promise.all(
- orders.map(function(order) {
- return store.get(order.id).then(function(product) {
+ orders.map((order) => {
+ return store.get(order.id).then((product) => {
  return decrementQuantity(product, order);
  });
  })
@@ -539,9 +539,9 @@ Now we need to check if there are enough items left in the `products` object sto
 Replace TODO 5.6 in `main.js` with the following code:
 
 ```
-return new Promise(function(resolve, reject) {
- var item = product;
- var qtyRemaining = item.quantity - order.quantity;
+return new Promise((resolve, reject) => {
+ const item = product;
+ const qtyRemaining = item.quantity - order.quantity;
  if (qtyRemaining < 0) {
  console.log('Not enough ' + product.id + ' left in stock!');
  document.getElementById('receipt').innerHTML =