app.py

from flask import Flask, render_template, url_for, request, redirect
from flask_sqlalchemy import SQLAlchemy
from datetime import datetime
import pytz

app = Flask(__name__)
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///test.db'
db = SQLAlchemy(app)

def get_gmt8_time():
    timezone = pytz.timezone('Asia/Singapore')
    return datetime.now(timezone)

class ToDo(db.Model):
    id = db.Column(db.Integer, primary_key = True)
    content = db.Column(db.String(200), nullable = False)
    date_created = db.Column(db.DateTime, default = get_gmt8_time())

    def __repr__(self):
        return '<Task %r>' % self.id

@app.route('/', methods = ['POST', 'GET'])
def index():
    if request.method == 'POST':
        task_content = request.form['content']
        new_task = ToDo(content = task_content)

        try:
            db.session.add(new_task)
            db.session.commit()
            return redirect('/')
        except:
            return 'There was an issue adding your task.'
        
    else:   
        tasks = ToDo.query.order_by(ToDo.date_created).all()
        return render_template('index.html', tasks = tasks)
    
@app.route('/delete/<int:id>')
def delete(id):
    task_to_delete = ToDo.query.get_or_404(id)

    try:
        db.session.delete(task_to_delete)
        db.session.commit()
        return redirect('/')
    except:
        return 'There was a problem deleting your task.'
    
@app.route('/update/<int:id>', methods = ['GET', 'POST'])
def update(id):
    task = ToDo.query.get_or_404(id)

    if request.method == 'POST':
        task.content = request.form['content']

        try:
            db.session.commit()
            return redirect('/')
        except:
            return 'There was a problem updating your task.'
        
    else:
        return render_template('update.html', task = task)


if __name__ == "__main__":
    app.run(debug = True)