A modularized Point of Sale System, designed using PyQt python GUI.

This an image of the products page in the system.

There A bunch of other pages and functionalities, most are still being developed. Much will be posted here after the system has developed. Feel free and welcome to collaborate and pull request.

to run designer, use this command pyqt5-tools designer pyuic5 pyuic5 -x file_name.ui -o test.py

the userlogin I have now, which works import sqlite3 from PyQt5.QtWidgets import * from PyQt5.QtCore import * from PyQt5.QtGui import * from uifiles.login_ui import Ui_Form from pages.dialogs import AlertManager from pages.dialogs import AlertManager import logging

logging.basicConfig(level=logging.DEBUG, filename='app.log', filemode='a', format='%(name)s - %(levelname)s - %(message)s')

class LoginPage(QWidget, Ui_Form): def init(self, switch_to_admin_page, switch_to_dashboard_page): super().init() self.switch_to_admin_page = switch_to_admin_page self.switch_to_dashboard_page = switch_to_dashboard_page

    try:
        self.conn = sqlite3.connect('products.db')
        self.cursor = self.conn.cursor()
        self.cursor.execute("SELECT COUNT(*) FROM user WHERE role='admin'")
        self.has_admin = self.cursor.fetchone()[0] > 0 
    except sqlite3.Error as e:
        logging.error(f"Database error: {e}")
        QMessageBox.critical(self, 'Database Error', f"An error occurred: {e}")
        sys.exit(1)

    self.setupUi(self)  # Set up the UI from the generated code
    self.init_ui()

def init_ui(self):
    self.pushButton.clicked.connect(self.user_authenticate)
    self.label_5.clicked.connect(self.admin_authenticate)

def admin_authenticate(self):
    try:
        if not self.has_admin:
            self.cursor.execute("SELECT COUNT(*) FROM user WHERE role='admin'")
            self.has_admin = self.cursor.fetchone()[0] > 0

        if self.has_admin:
            dialog = AdminLoginDialog(self.conn, self.switch_to_admin_page)
            if dialog.exec_() == QDialog.Accepted:
                pass
        else:
            dialog = AdminSetupDialog(self.conn)
            if dialog.exec_() == QDialog.Accepted:
                self.cursor.execute("SELECT COUNT(*) FROM user WHERE role='admin'")
                self.has_admin = self.cursor.fetchone()[0] > 0
    except sqlite3.Error as e:
        logging.error(f"Database error: {e}")
        QMessageBox.critical(self, 'Database Error', f"An error occurred: {e}")

def user_authenticate(self):
    username = self.lineEdit.text()
    password = self.lineEdit_2.text()
    try:
        self.cursor.execute("SELECT * FROM user WHERE username=? AND password=? AND role='user'", (username, password))
        result = self.cursor.fetchone()
        if result:
            self.switch_to_dashboard_page()
            self.lineEdit.clear()
            self.lineEdit_2.clear()
            self.show_alert_dialog()
        else:
            QMessageBox.warning(self, 'Error', 'Invalid credentials')
    except sqlite3.Error as e:
        logging.error(f"Database error: {e}")
        QMessageBox.critical(self, 'Database Error', f"An error occurred: {e}")

def show_alert_dialog(self):
    alert_manager = AlertManager()

def closeEvent(self, event):
    self.conn.close()
    event.accept()

Admin Setup Dialog

class AdminSetupDialog(QDialog): def init(self, conn): super().init()

    self.conn = sqlite3.connect('products.db')
    self.cursor = self.conn.cursor()


    self.resize(320,250)
    self.setWindowTitle('Initial setUp for SuperUser')

    self.layout = QVBoxLayout()
    self.setLayout(self.layout)

    self.new_username_label = QLabel('Username:')
    self.new_username_input = QLineEdit()
    self.new_password_label = QLabel(' Password:')
    self.new_password_input = QLineEdit()
    self.new_password_input.setEchoMode(QLineEdit.Password)
    self.confirm_password_label = QLabel('Confirm Password:')
    self.confirm_password_input = QLineEdit()
    self.confirm_password_input.setEchoMode(QLineEdit.Password)

    self.save_button = QPushButton('Create SuperUser')
    self.save_button.clicked.connect(self.save_new_admin)

    self.layout.addWidget(self.new_username_label)
    self.layout.addWidget(self.new_username_input)
    self.layout.addWidget(self.new_password_label)
    self.layout.addWidget(self.new_password_input)
    self.layout.addWidget(self.confirm_password_label)
    self.layout.addWidget(self.confirm_password_input)
    self.layout.addWidget(self.save_button)

def save_new_admin(self):
    new_username = self.new_username_input.text()
    new_password = self.new_password_input.text()
    confirm_password = self.confirm_password_input.text()

    if not new_username or not new_password or not confirm_password:
        QMessageBox.warning(self, 'Error', 'Fields cannot be empty')
        return

    if new_password != confirm_password:
        QMessageBox.warning(self, 'Error', 'Passwords do not match')
        return

    self.cursor = self.conn.cursor()
    try:
        self.cursor.execute('INSERT INTO user (username, password, role) VALUES(?, ?, ?)',  (new_username, new_password, 'admin'))
        self.conn.commit()
        QMessageBox.information(self, 'Success', 'SuperUser created successfully')
        self.accept()
    except sqlite3.IntegrityError:
        QMessageBox.warning(self, 'Error', 'Username already exists')

Admin Login Dialog

class AdminLoginDialog(QDialog): def init(self, conn, switch_to_admin_page): super().init()

    self.resize(280, 200)

    self.conn = conn
    self.switch_to_admin_page = switch_to_admin_page
    self.setWindowTitle('Login as Superuser')

    self.layout = QVBoxLayout()
    self.setLayout(self.layout)

    self.username_label = QLabel('Username:')
    self.username_input = QLineEdit()
    self.password_label = QLabel('Password:')
    self.password_input = QLineEdit()
    self.password_input.setEchoMode(QLineEdit.Password)

    self.login_button = QPushButton('Login')
    self.login_button.clicked.connect(self.authenticate)

    self.layout.addWidget(self.username_label)
    self.layout.addWidget(self.username_input)
    self.layout.addWidget(self.password_label)
    self.layout.addWidget(self.password_input)
    self.layout.addWidget(self.login_button)

def authenticate(self):
    username = self.username_input.text()
    password = self.password_input.text()

    cursor = self.conn.cursor()
    cursor.execute("SELECT * FROM user WHERE username=? AND password=? AND role='admin'", (username, password))
    result = cursor.fetchone()

    if result:
        # QMessageBox.information(self, 'Success', 'Admin login successful')
        self.accept()
        self.switch_to_admin_page()
        # Open admin page or perform other actions
    else:
        QMessageBox.warning(self, 'Error', 'Invalid credentials')

if name == "main": import sys app = QApplication(sys.argv)

# Example switch functions
def switch_to_admin_page():
    print("Switching to admin page...")

def switch_to_dashboard_page():
    print("Switching to dashboard page...")

login_page = LoginPage(switch_to_admin_page, switch_to_dashboard_page)
login_page.show()

sys.exit(app.exec_())

import sqlite3 from PyQt5.QtWidgets import * from PyQt5.QtCore import * from PyQt5.QtGui import * from uifiles.login_ui import Ui_Form from pages.dialogs import AlertManager

class LoginPage(QWidget, Ui_Form): def init(self, switch_to_admin_page, switch_to_dashboard_page): super().init() self.switch_to_admin_page = switch_to_admin_page self.switch_to_dashboard_page = switch_to_dashboard_page

    self.conn = sqlite3.connect('products.db')
    self.cursor = self.conn.cursor()
    self.cursor.execute("SELECT COUNT(*) FROM user WHERE role='admin'")
    self.has_admin = self.cursor.fetchone()[0] > 0 

    # self.init_db()
    self.setupUi(self)  # Set up the UI from the generated code
    self.init_ui()

# def init_db(self):
#     self.conn = sqlite3.connect('products.db')
#     self.cursor = self.conn.cursor()

    # self.cursor.execute("SELECT COUNT(*) FROM user WHERE role='admin'")
    # has_admin = self.cursor.fetchone()[0] > 0
    # self.conn.commit()

def init_ui(self):
    self.pushButton.clicked.connect(self.user_authenticate)
    self.label_5.clicked.connect(self.admin_authenticate)

def admin_authenticate(self):
    if not self.has_admin:  # Only check if no admin exists
        self.cursor.execute("SELECT COUNT(*) FROM user WHERE role='admin'")
        self.has_admin = self.cursor.fetchone()[0] > 0

    if self.has_admin:
        dialog = AdminLoginDialog(self.conn, self.switch_to_admin_page)
        if dialog.exec_() == QDialog.Accepted:
            pass
    else:
        dialog = AdminSetupDialog(self.conn)
        if dialog.exec_() == QDialog.Accepted:
            # Update has_admin after successful setup (optional)
            self.cursor.execute("SELECT COUNT(*) FROM user WHERE role='admin'")
            self.has_admin = self.cursor.fetchone()[0] > 0
            

def user_authenticate(self):
    username = self.lineEdit.text()
    password = self.lineEdit_2.text()
    self.cursor.execute("SELECT * FROM user WHERE username=? AND password=? AND role='user'", (username, password))
    result = self.cursor.fetchone()
    if result:
        self.switch_to_dashboard_page()
        self.lineEdit.clear()
        self.lineEdit_2.clear()
        self.show_alert_dialog()
    else:
        QMessageBox.warning(self, 'Error', 'Invalid credentials')

def show_alert_dialog(self):
    alert_manager = AlertManager()

Admin Setup Dialog

class AdminSetupDialog(QDialog): def init(self, conn): super().init()

    self.conn = sqlite3.connect('products.db')
    self.cursor = self.conn.cursor()


    self.resize(320,250)
    self.setWindowTitle('Initial setUp for SuperUser')

    self.layout = QVBoxLayout()
    self.setLayout(self.layout)

    self.new_username_label = QLabel('Username:')
    self.new_username_input = QLineEdit()
    self.new_password_label = QLabel(' Password:')
    self.new_password_input = QLineEdit()
    self.new_password_input.setEchoMode(QLineEdit.Password)
    self.confirm_password_label = QLabel('Confirm Password:')
    self.confirm_password_input = QLineEdit()
    self.confirm_password_input.setEchoMode(QLineEdit.Password)

    self.save_button = QPushButton('Create SuperUser')
    self.save_button.clicked.connect(self.save_new_admin)

    self.layout.addWidget(self.new_username_label)
    self.layout.addWidget(self.new_username_input)
    self.layout.addWidget(self.new_password_label)
    self.layout.addWidget(self.new_password_input)
    self.layout.addWidget(self.confirm_password_label)
    self.layout.addWidget(self.confirm_password_input)
    self.layout.addWidget(self.save_button)

def save_new_admin(self):
    new_username = self.new_username_input.text()
    new_password = self.new_password_input.text()
    confirm_password = self.confirm_password_input.text()

    if not new_username or not new_password or not confirm_password:
        QMessageBox.warning(self, 'Error', 'Fields cannot be empty')
        return

    if new_password != confirm_password:
        QMessageBox.warning(self, 'Error', 'Passwords do not match')
        return

    self.cursor = self.conn.cursor()
    try:
        self.cursor.execute('INSERT INTO user (username, password, role) VALUES(?, ?, ?)',  (new_username, new_password, 'admin'))
        self.conn.commit()
        QMessageBox.information(self, 'Success', 'SuperUser created successfully')
        self.accept()
    except sqlite3.IntegrityError:
        QMessageBox.warning(self, 'Error', 'Username already exists')

Admin Login Dialog

class AdminLoginDialog(QDialog): def init(self, conn, switch_to_admin_page): super().init()

    self.resize(280, 200)

    self.conn = conn
    self.switch_to_admin_page = switch_to_admin_page
    self.setWindowTitle('Login as Superuser')

    self.layout = QVBoxLayout()
    self.setLayout(self.layout)

    self.username_label = QLabel('Username:')
    self.username_input = QLineEdit()
    self.password_label = QLabel('Password:')
    self.password_input = QLineEdit()
    self.password_input.setEchoMode(QLineEdit.Password)

    self.login_button = QPushButton('Login')
    self.login_button.clicked.connect(self.authenticate)

    self.layout.addWidget(self.username_label)
    self.layout.addWidget(self.username_input)
    self.layout.addWidget(self.password_label)
    self.layout.addWidget(self.password_input)
    self.layout.addWidget(self.login_button)

def authenticate(self):
    username = self.username_input.text()
    password = self.password_input.text()

    cursor = self.conn.cursor()
    cursor.execute("SELECT * FROM user WHERE username=? AND password=? AND role='admin'", (username, password))
    result = cursor.fetchone()

    if result:
        # QMessageBox.information(self, 'Success', 'Admin login successful')
        self.accept()
        self.switch_to_admin_page()
        # Open admin page or perform other actions
    else:
        QMessageBox.warning(self, 'Error', 'Invalid credentials')

if name == "main": import sys app = QApplication(sys.argv)

# Example switch functions
def switch_to_admin_page():
    print("Switching to admin page...")

def switch_to_dashboard_page():
    print("Switching to dashboard page...")

login_page = LoginPage(switch_to_admin_page, switch_to_dashboard_page)
login_page.show()

sys.exit(app.exec_())