Update the JavaScript according to the "feedback to improve the code"

Author: AdiyahFarhan

debugging/book-library/script.js

@@ -7,97 +7,126 @@ window.addEventListener("load", function (e) {
 
 function populateStorage() {
   if (myLibrary.length == 0) {
-    let book1 = new Book("Robison Crusoe", "Daniel Defoe", "252", true);
+    let book1 = new Book("Robison Crusoe", "Daniel Defoe", 252, true);
     let book2 = new Book(
       "The Old Man and the Sea",
       "Ernest Hemingway",
-      "127",
+      127,
       true
     );
     myLibrary.push(book1);
     myLibrary.push(book2);
-    render();
   }
 }
 
-const title = document.getElementById("title");
-const author = document.getElementById("author");
-const pages = document.getElementById("pages");
-const check = document.getElementById("check");
+const titleElement = document.getElementById("title");
+const authorElement = document.getElementById("author");
+const pagesElement = document.getElementById("pages");
+const checkElement = document.getElementById("check");
 
 //check the right input from forms and if its ok -> add the new book (object in array)
 //via Book function and start render function
 function submit() {
-  if (
-    title.value == null ||
-    title.value == "" ||
-    pages.value == null ||
-    pages.value == ""
-  ) {
+  if (!titleElement.value || !authorElement.value || !pagesElement.value) {
     alert("Please fill all fields!");
     return false;
+  } else if (!titleElement.value.match(/^(?=.*[a-zA-Z])[a-zA-Z ]+$/)) {
+    alert("Please enter a valid book title!");
+    return false;
+  } else if (!authorElement.value.match(/^(?=.*[a-zA-Z])[a-zA-Z ]+$/)) {
+    alert("Please enter a valid author name!");
+    return false;
+  } else if (!pagesElement.value.match(/^[0-9]+$/)) {
+    alert("Please enter a valid number of pages!");
+    return false;
   } else {
-    let book = new Book(title.value, author.value, pages.value, check.checked);
+    let book = new Book(
+      titleElement.value,
+      authorElement.value,
+      pagesElement.value,
+      checkElement.checked
+    );
+
     myLibrary.push(book);
     render();
   }
 }
 
 function Book(title, author, pages, check) {
-  this.title = title;
-  this.author = author;
-  this.pages = pages;
+  this.title = title.trim(); //remove leading/trailing spaces
+  this.author = author.trim();
+  this.pages = Number(pages); // Ensure pages is a number
   this.check = check;
 }
 
 function render() {
-  let table = document.getElementById("display");
-  let rowsNumber = table.rows.length;
+  //Method 1: To clear the table
+  //let table = document.getElementById("display");
+  //delete all rows except the first one (header)
+  //let rowsNumber = table.rows.length;
   //delete old table
-  for (let n = rowsNumber - 1; n > 0; n--) {
-    table.deleteRow(n);
-  }
+  //for (let n = rowsNumber - 1; n > 0; n--) {
+  //table.deleteRow(n);
+  //}
+
+  //Method 2: To clear the table in one operation
+  //replaceChildren() is a modern method to clear all children of an element
+  let tableBody = document.querySelector("tbody");
+  tableBody.replaceChildren(); // Clear the table body
+
   //insert updated row and cells
   let length = myLibrary.length;
   for (let i = 0; i < length; i++) {
-    let row = table.insertRow(1);
+    let row = tableBody.insertRow(0); // Insert a new row at the beginning of the table body
     let titleCell = row.insertCell(0);
     let authorCell = row.insertCell(1);
     let pagesCell = row.insertCell(2);
     let wasReadCell = row.insertCell(3);
     let deleteCell = row.insertCell(4);
-    titleCell.innerHTML = myLibrary[i].title;
-    authorCell.innerHTML = myLibrary[i].author;
-    pagesCell.innerHTML = myLibrary[i].pages;
+
+    //innerHTML was replaced with textContent for cleaner text handling / code semantics.
+    titleCell.textContent = myLibrary[i].title;
+    authorCell.textContent = myLibrary[i].author;
+    pagesCell.textContent = myLibrary[i].pages;
 
     //add and wait for action for read/unread button
-    let changeBut = document.createElement("button");
-    changeBut.id = i;
-    changeBut.className = "btn btn-success";
-    wasReadCell.appendChild(changeBut);
+    let readButton = document.createElement("button");
+
+    // readButton.id = i; /
+    // No need for an ID here, as we can use the index directly
+    readButton.className = "btn btn-success";
+    wasReadCell.appendChild(readButton);
     let readStatus = "";
     if (myLibrary[i].check == false) {
       readStatus = "No";
     } else {
       readStatus = "Yes";
     }
-    changeBut.innerText = readStatus;
+    readButton.innerText = readStatus;
 
-    changeBut.addEventListener("click", function () {
+    readButton.addEventListener("click", function () {
       myLibrary[i].check = !myLibrary[i].check;
       render();
     });
 
     //add delete button to every row and render again
-    let delButton = document.createElement("button");
-    delButton.id = i + 5;
-    deleteCell.appendChild(delButton);
-    delButton.className = "btn btn-warning";
-    delButton.innerHTML = "Delete";
-    delButton.addEventListener("click", function () {
-      alert(`You've deleted title: ${myLibrary[i].title}`);
-      myLibrary.splice(i, 1);
-      render();
+    let deleteButton = document.createElement("button");
+
+    // No need to set an ID for the delete button, as we can use the index directly
+    //deleteButton.id = i + 5;
+    deleteCell.appendChild(deleteButton);
+    deleteButton.className = "btn btn-warning";
+    deleteButton.textContent = "Delete";
+    deleteButton.addEventListener("click", function () {
+      const deletedTitle = myLibrary[i].title; //save the title of the book to be deleted
+      myLibrary.splice(i, 1); // Remove the book from the library array
+      render(); // update the table after deletion
+
+      // Use setTimeout to ensure the alert is shown after the render
+      // This is useful to ensure the UI is updated before showing the alert
+      setTimeout(() => {
+        alert(`You've deleted title: ${deletedTitle}`);
+      }, 0.5);
     });
   }
 }