Skip to content

London | 25-ITP-Sept | Samuel Tarawally | Sprint 2 | Book Library #364

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
Tarawally wants to merge 6 commits into
base: main
Choose a base branch
from
Open

London | 25-ITP-Sept | Samuel Tarawally | Sprint 2 | Book Library #364

Show file tree
Hide file tree
Changes from 5 commits
Commits
Show all changes
6 commits
Select commit Hold shift + click to select a range
1582ca0
fix(book-library): resolve all functional bugs and update the html st…
Tarawally Dec 17, 2025
998034a
fix(book-library): revert out of scope style changes
Tarawally Dec 18, 2025
c83cbbb
refactor: standardises variable scoping and simplifies the rendering …
Tarawally Dec 19, 2025
c968435
feat: sanitises user inputs and implements stricter guard clauses
Tarawally Dec 19, 2025
8b302b9
feat: adds input field resets and descriptive deletion notifications
Tarawally Dec 19, 2025
c8e3a34
fix(book-library): initialise storage and validate page input
Tarawally Dec 21, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
55 changes: 23 additions & 32 deletions debugging/book-library/index.html
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,12 +1,9 @@
<!DOCTYPE html>
<html>
<html lang="en">
<head>
<title> </title>
<meta
charset="utf-8"
name="viewport"
content="width=device-width, initial-scale=1.0"
/>
<title>Book Library</title>
<meta charset="utf-8" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.4.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.16.0/umd/popper.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.4.1/js/bootstrap.min.js"></script>
Expand All @@ -19,7 +16,7 @@

<body>
<div class="jumbotron text-center">
<h1>Library</h1>
<h1>My Book Library</h1>
<p>Add books to your virtual library</p>
</div>

Expand All @@ -31,15 +28,15 @@ <h1>Library</h1>
<div class="form-group">
<label for="title">Title:</label>
<input
type="title"
type="text"
class="form-control"
id="title"
name="title"
required
/>
<label for="author">Author: </label>
<input
type="author"
type="text"
class="form-control"
id="author"
name="author"
Expand All @@ -64,32 +61,26 @@ <h1>Library</h1>
<input
type="submit"
value="Submit"
class="btn btn-primary"
onclick="submit();"
class="btn btn-primary btn-block"
id="submit-book-btn"
/>
</div>
</div>

<table class="table" id="display">
<thead class="thead-dark">
<tr>
<th>Title</th>
<th>Author</th>
<th>Number of Pages</th>
<th>Read</th>
<th></th>
</tr>
</thead>
<tbody>
<tr>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
</tr>
</tbody>
</table>
<div class="table-responsive">
<table class="table table-hover" id="display">
<thead class="thead-dark">
<tr>
<th>Title</th>
<th>Author</th>
<th>Number of Pages</th>
<th>Read</th>
<th></th>
</tr>
</thead>
<tbody></tbody>
</table>
</div>

<script src="script.js"></script>
</body>
Expand Down
152 changes: 78 additions & 74 deletions debugging/book-library/script.js
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,46 +1,53 @@
const titleInput = document.getElementById("title");
const authorInput = document.getElementById("author");
const pagesInput = document.getElementById("pages");
const readCheckbox = document.getElementById("check");
const table = document.getElementById("display");
const submitBtn = document.getElementById("submit-book-btn");

let myLibrary = [];

window.addEventListener("load", function (e) {
window.addEventListener("load", () => {
populateStorage();
render();
});

submitBtn.addEventListener("click", addBook);

function populateStorage() {
if (myLibrary.length == 0) {
let book1 = new Book("Robison Crusoe", "Daniel Defoe", "252", true);
let book2 = new Book(
"The Old Man and the Sea",
"Ernest Hemingway",
"127",
true
);
myLibrary.push(book1);
myLibrary.push(book2);
render();
const storedLibrary = localStorage.getItem("myLibrary");
if (storedLibrary) {
myLibrary = JSON.parse(storedLibrary);
}
Comment on lines 19 to 37
Copy link
Contributor

@cjyuan cjyuan Dec 18, 2025

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

  • Shouldn't myLibrary be populated with some data for users who do not have any data in their browser's local storage?

  • The objects in the restored array are not instances of Book. A a result, myLibrary will end up with two kinds of objects: Generic objects and Book objects (added on line 42). Even though this is not a problem for this simple app, it is a better practice to consistently keep the same type of data in myLibrary.

Copy link
Contributor

@cjyuan cjyuan Dec 19, 2025 •
edited
Loading

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Can you also address the comment I left on the code on lines 18-21 in the previous review?

Copy link
Author

@Tarawally Tarawally Dec 21, 2025

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

To populate data for users who do not have any, and to restore plain data objects back into book objects, the following code snippet has been applied:

  const storedLibrary = localStorage.getItem("myLibrary");

  if (storedLibrary) {
    const rawData = JSON.parse(storedLibrary);
    // Rehydrates plain data back into Book objects
    myLibrary = rawData.map(
      (data) =>
        new Book(data.title, data.author, Number(data.pages), data.check)
    );
  } else {
    // Seeds data for new users
    myLibrary = [
      new Book("The Hobbit", "J.R.R. Tolkien", 295, false),
      new Book("1984", "George Orwell", 328, true),
      new Book("Robinson Crusoe", "Daniel Defoe", 252, true),
      new Book("The Old Man and the Sea", "Ernest Hemingway", 127, false),
    ];
    saveStorage();
  }

Copy link
Contributor

@cjyuan cjyuan Dec 21, 2025

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Well done.

Please note that if pages are consistently stored values of type number, we would not need the conversion Number(data.pages).

}

const title = document.getElementById("title");
const author = document.getElementById("author");
const pages = document.getElementById("pages");
const check = 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 == ""
) {
function saveStorage() {
localStorage.setItem("myLibrary", JSON.stringify(myLibrary));
}

// Trims input values and prevents empty submissions
function addBook(e) {
if (e) e.preventDefault();

// Trims input whitespace to sanitise entries
const title = titleInput.value.trim();
const author = authorInput.value.trim();
const pages = pagesInput.value.trim();

if (!title || !author || !pages) {
alert("Please fill all fields!");
return false;
} else {
let book = new Book(title.value, title.value, pages.value, check.checked);
library.push(book);
render();
return;
}
const book = new Book(title, author, pages, readCheckbox.checked);
Copy link
Contributor

@cjyuan cjyuan Dec 19, 2025

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

On line 41, the value of pages can still be a string that represents an invalid number of pages.
Can you ensure the value of pages represents a valid number of pages.

Copy link
Author

@Tarawally Tarawally Dec 21, 2025

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

To address this I've made the following changes:

  const pages = Number(pagesInput.value);

  // Validates input: checks for empty strings, non-numbers, or negative values
  if (!title || !author || isNaN(pages) || pages <= 0) {
    alert("Please enter valid book details. Pages must be a positive number.");
    return;
  }
  const book = new Book(title, author, pages, readCheckbox.checked);

Copy link
Contributor

@cjyuan cjyuan Dec 21, 2025

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Not all positive finite numbers are valid "number of pages" though. What other numbers should also be rejected?

Copy link
Author

@Tarawally Tarawally Dec 21, 2025 •
edited
Loading

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

float would be a problem so i guess this would be better

if (!title || !author || isNaN(pages) || pages <= 0 || !Number.isInteger(pages)) {}

Copy link
Author

@Tarawally Tarawally Dec 21, 2025

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

this could also be shorten to

if (!title || !author || !Number.isInteger(pages) || pages <= 0) {}

myLibrary.push(book);
saveStorage();
render();

// Resets the entry form after adding a book
titleInput.value = "";
authorInput.value = "";
pagesInput.value = "";
readCheckbox.checked = false;
}

function Book(title, author, pages, check) {
Expand All @@ -51,53 +58,50 @@ function Book(title, author, pages, check) {
}

function render() {
let table = document.getElementById("display");
let rowsNumber = table.rows.length;
//delete old table
for (let n = rowsNumber - 1; n > 0; n-- {
table.deleteRow(n);
}
//insert updated row and cells
let length = myLibrary.length;
for (let i = 0; i < length; i++) {
let row = table.insertRow(1);
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;

//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 readStatus = "";
if (myLibrary[i].check == false) {
readStatus = "Yes";
} else {
readStatus = "No";
}
changeBut.innerText = readStatus;

changeBut.addEventListener("click", function () {
myLibrary[i].check = !myLibrary[i].check;
const tbody = table.querySelector("tbody");
tbody.innerHTML = "";

myLibrary.forEach((book, i) => {
const row = tbody.insertRow(-1);

// Inserts new cells into the table row
const titleCell = row.insertCell(0);
const authorCell = row.insertCell(1);
const pagesCell = row.insertCell(2);
const wasReadCell = row.insertCell(3);
const deleteCell = row.insertCell(4);

// Prevents XSS by inserting data as textContent
titleCell.textContent = book.title;
authorCell.textContent = book.author;
pagesCell.textContent = book.pages;

// Toggles the read status with a ternary operator
const readBtn = document.createElement("button");
readBtn.className = book.check
? "btn btn-success"
: "btn btn-outline-secondary";
readBtn.textContent = book.check ? "Yes" : "No";
wasReadCell.appendChild(readBtn);

readBtn.addEventListener("click", () => {
book.check = !book.check;
saveStorage();
render();
});

//add delete button to every row and render again
let delButton = document.createElement("button");
delBut.id = i + 5;
deleteCell.appendChild(delBut);
delBut.className = "btn btn-warning";
delBut.innerHTML = "Delete";
delBut.addEventListener("clicks", function () {
alert(`You've deleted title: ${myLibrary[i].title}`);
// Deletes the book and notifies the user
const deleteBtn = document.createElement("button");
deleteBtn.className = "btn btn-danger btn-sm";
deleteBtn.textContent = "Delete";
deleteCell.appendChild(deleteBtn);

deleteBtn.addEventListener("click", () => {
const deletedTitle = book.title;
myLibrary.splice(i, 1);
saveStorage();
render();
alert(`Success: "${deletedTitle}" has been removed.`);
});
}
});
}