added skeleton for flask-login

lab-15/dbhelper_flasklogin.py

+import pymysql
+import datetime
+
+class DBHelper:
+
+    def __init__(self):
+        self.db = pymysql.connect(host='localhost',
+            user='mytwits_user',
+            passwd='mytwits_password',
+            db='mytwits')
+
+    def get_user(self, user_id):
+        query = "select * from users where user_id=%s"
+        with self.db.cursor() as cursor:
+            cursor.execute(query,user_id)
+            return  cursor.fetchone()
+
+    def get_all_twits(self):
+        query = "select u.username, t.twit_id, t.twit, t.created_at from twits t, users u where t.user_id=u.user_id order by t.created_at desc;"
+        with self.db.cursor() as cursor:
+            cursor.execute(query)
+            return cursor.fetchall() # The method fetches all (or all remaining) rows of a query result set and returns a list of tuples
+
+    def get_twit(self,twit_id):
+        query = "select twit from twits where twit_id=%s"
+        with self.db.cursor() as cursor:
+            cursor.execute(query, twit_id)
+            return cursor.fetchone()  
+            # more detals about cursor.fetchone at
+            # https://dev.mysql.com/doc/connector-python/en/connector-python-api-mysqlcursor-fetchone.html
+
+    def add_twit(self,twit,user_id):
+        query = "insert into twits (twit,user_id) values \
+        (%s,%s);"
+        with self.db.cursor() as cursor:
+            cursor.execute(query, (twit,user_id))
+            return self.db.commit()
+
+    def update_twit(self,twit,twit_id):
+        query = "update twits set twit=%s where twit_id=%s"
+        with self.db.cursor() as cursor:
+            cursor.execute(query,(twit,twit_id))
+            return self.db.commit()
+
+    def delete_twit(self,twit_id):
+        query = "delete from twits where twit_id=%s"
+        with self.db.cursor() as cursor:
+            cursor.execute(query, twit_id)
+            return self.db.commit()
+
+    def check_password(self,username,password):
+        query = "select user_id from users where username = %s and password=%s;"
+        with self.db.cursor() as cursor:
+            user_id = None
+            cursor.execute(query,(username,password))
+            return cursor.fetchone()

lab-15/forms_flasklogin.py

+from flask_wtf import FlaskForm
+from wtforms import StringField
+from wtforms import HiddenField
+from wtforms import PasswordField
+from wtforms import SubmitField
+from wtforms import validators
+
+class addTwitForm(FlaskForm):
+    twit = StringField('twit', validators = [validators.DataRequired()])
+    submit = SubmitField('submit', [validators.DataRequired()])
+
+class editTwitForm(FlaskForm):
+    twit = StringField('twit', validators = [validators.DataRequired()])
+    twit_id = HiddenField('twit_id')
+    submit = SubmitField('submit', [validators.DataRequired()])
+
+class loginForm(FlaskForm):
+    username = StringField('username', validators = [validators.DataRequired()])
+    password = PasswordField('password', validators =[validators.DataRequired()])
+    password2 = PasswordField('password2', validators=[validators.DataRequired(),
+        validators.EqualTo('password', message='Passwords must match')])
+    submit = SubmitField('submit', [validators.DataRequired()])
+
+

lab-15/mytwits_mysql_flasklogin.py

+from flask import Flask, request
+from flask import render_template
+from flask import redirect, url_for
+from flask import session, flash, abort
+from vs_url_for import vs_url_for
+from forms_flasklogin import addTwitForm, editTwitForm, loginForm
+from dbhelper_flasklogin import DBHelper
+
+#>>> import flask_login modules here
+
+#>>> import the user class here
+
+#>>> create an instance of LoginManager here
+
+app = Flask(__name__)
+db = DBHelper()
+#>>> initiate your login_manager here
+
+app.secret_key = 'A0Zr98j/3yX R~XHH!jmN]LWX/,?RT'
+
+#>>> add your user_loader callback function here
+
+@app.route('/')
+def index():
+    twits = db.get_all_twits()
+    return render_template("mytwits_mysql_flasklogin.html", twits=twits)
+
+@app.route('/add_twit', methods = ['GET', 'POST'])
+@login_required
+def add_twit():
+    form = addTwitForm()
+    if form.validate_on_submit():
+        twit = form.twit.data
+        db.add_twit(twit,session['user_id'])
+        return redirect(vs_url_for('index'))
+    return render_template('add_twit_mysql_flasklogin.html',form=form)
+
+@app.route('/edit_twit', methods = ['GET', 'POST'])
+@login_required
+def edit_twit():
+    form = editTwitForm()
+    if request.args.get('id'):
+        twit_id = request.args.get('id')
+        twit = db.get_twit(twit_id)
+        form.twit.data = twit[0]
+        form.twit_id.data = twit_id
+        return render_template('edit_twit_mysql_flasklogin.html',form=form,twit=twit)
+    if form.validate_on_submit():
+        twit = form.twit.data
+        twit_id = form.twit_id.data
+        db.update_twit(twit,twit_id)
+        return redirect(vs_url_for('index'))
+    return render_template('edit_twit_mysql_flasklogin.html',form=form)
+
+@app.route('/delete_twit', methods = ['GET', 'POST'])
+@login_required
+def delete_twit():
+    if request.args.get('id'):
+        twit_id = request.args.get('id')
+        twit = db.delete_twit(twit_id)
+    return redirect(vs_url_for('index'))
+   
+@app.route('/login', methods = ['GET', 'POST'])
+def login():
+    form = loginForm()
+    if form.validate_on_submit():
+        password = form.password.data
+        username = form.username.data
+        user_id = db.check_password(username,password)
+        if user_id:
+
+            #>>> instantiate the user here
+
+            #>>> login the user here
+
+            flash('login successful!')
+            return redirect(vs_url_for('index'))
+        else:
+            flash('login unsuccessful!')
+    return render_template('login.html',form=form)
+
+@app.route('/logout')
+def logout():
+
+    #>>> logout the user here
+
+    return redirect(vs_url_for('index'))
+
+if __name__ == '__main__':
+    app.run(debug=True,host='0.0.0.0',port=8000)

lab-15/templates/add_twit_mysql_flasklogin.html

+{% extends "base_flasklogin.html" %}
+{% block body %}
+
+<div class="jumbotron">
+
+<div >
+	<form class="form-horizontal" method="post" action="/add_twit">
+    {{ form.csrf_token }}
+    <div class='form-group'>
+        <div class='col-md-6'>
+            {% if form.twit.errors %}
+                <ul class='errors'> 
+                    {% for error in form.twit.errors %}
+                        <li>{{ error }}</li>
+                    {% endfor %}
+                </ul>
+            {% endif %}
+            {{ form.twit(class='form-control',placeholder='twit') }}
+        </div>
+     </div>
+    <div class='form-group'>
+        <div class='col-md-6'>
+            {{ form.submit(class='btn btn-primary btn-block') }}
+        </div>
+    </div>
+    </form>
+</div>
+
+</div>
+
+
+{% endblock %}

lab-15/templates/base_flasklogin.html

+<!DOCTYPE html>
+<head>
+
+<meta charset="utf-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1">
+
+    <link rel="stylesheet"
+    href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-beta.3/css/bootstrap.min.css"
+    integrity="sha384-Zug+QiDoJOrZ5t4lssLdxGhVrurbmBWopoEl+M6BdEfwnCJZtKxi1KgxUyJq13dy"
+    crossorigin="anonymous">
+
+
+</head>
+<body>
+<div class="container">
+
+    <!--- flash messages -->
+    {% for category, message in get_flashed_messages(with_categories=true) %}
+    <div class="alert alert-dismissable alert-warning alert-{{ category }}">
+    <button type="button" class="close" data-dismiss="alert">&times;</button>
+    {{ message }}
+    </div>
+    {% endfor %}
+
+    {% current_user.is_authenticated %}
+        logged in as {{ session['username'] }}
+    {% endif %}
+
+    <!--- the body will come from a template that inherits from this one -->
+    {% block body %}{% endblock %}
+
+</div>
+
+<!-- Optional JavaScript -->
+    <!-- jQuery first, then Popper.js, then Bootstrap JS -->
+    <script src="https://code.jquery.com/jquery-3.2.1.slim.min.js" integrity="sha384-KJ3o2DKtIkvYIK3UENzmM7KCkRr/rE9/Qpg6aAZGJwFDMVNA/GpGFF93hXpG5KkN" crossorigin="anonymous"></script>
+    <script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.12.9/umd/popper.min.js" integrity="sha384-ApNbgh9B+Y1QKtv3Rn7W3mgPxhU9K/ScQsAP7hUibX39j7fakFPskvXusvfa0b4Q" crossorigin="anonymous"></script>
+    <script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-beta.3/js/bootstrap.min.js" integrity="sha384-a5N7Y/aK3qNeh15eJKGWxsqtnX/wWdSZSKp+81YjTmS15nvnvxKHuzaWwXHDli+4" crossorigin="anonymous"></script>
+
+
+
+</body>
+</html>

lab-15/templates/edit_twit_mysql_flasklogin.html

+{% extends "base_flasklogin.html" %}
+{% block body %}
+
+<div class="jumbotron">
+
+<div >
+	<form class="form-horizontal" method="post" action="/edit_twit">
+    {{ form.csrf_token }}
+    <div class='form-group'>
+        <div class='col-md-6'>
+            {% if form.twit.errors %}
+                <ul class='errors'> 
+                    {% for error in form.twit.errors %}
+                        <li>{{ error }}</li>
+                    {% endfor %}
+                </ul>
+            {% endif %}
+            {{ form.twit(class='form-control') }}
+        </div>
+     </div>
+	<div>
+		{{ form.twit_id }}
+	</div>
+    <div class='form-group'>
+        <div class='col-md-6'>
+            {{ form.submit(class='btn btn-primary btn-block') }}
+        </div>
+    </div>
+    </form>
+</div>
+
+</div>
+
+
+{% endblock %}

lab-15/templates/login_flasklogin.html

+{% extends "base_flasklogin.html" %}
+{% block body %}
+
+<div class="jumbotron">
+
+        <form class='form-horizontal' method="post">
+
+        {{ form.csrf_token }}
+
+        <div class='form-group'>
+            <div class='col-md-6'>
+                {% if form.username.errors %}
+                    <ul class='errors'> 
+                        {% for error in form.username.errors %}
+                            <li>{{ error }}</li>
+                        {% endfor %}
+                    </ul>
+                {% endif %}
+                {{ form.username(class='form-control',placeholder='username') }}
+            </div>
+        </div>
+        <div class='form-group'>
+            <div class='col-md-6'>
+                {% if form.password.errors %}
+                    <ul class='errors'> 
+                        {% for error in form.password.errors %}
+                            <li>{{ error }}</li>
+                        {% endfor %}
+                    </ul>
+                {% endif %}
+                {{
+                form.password(class='form-control',placeholder='password') }}
+            </div>
+        </div>
+        <div class='form-group'>
+            <div class='col-md-6'>
+                {% if form.password2.errors %}
+                    <ul class='errors'> 
+                        {% for error in form.password2.errors %}
+                            <li>{{ error }}</li>
+                        {% endfor %}
+                    </ul>
+                {% endif %}
+                {{ form.password2(class='form-control',placeholder='confirm password') }}
+            </div>
+        </div>
+        <div class='form-group'>
+            <div class='col-md-6'>
+                {{ form.submit(class='btn btn-primary btn-block') }}
+            </div>
+        </div>
+        </form>
+
+</div >
+
+
+{% endblock %}

lab-15/templates/mytwits_mysql_flasklogin.html

+{% extends "base_flasklogin.html" %}
+{% block body %}
+
+<div class="jumbotron">
+{% for twit in twits %}
+ <div class="row">
+  <div class="col-md-4">{{ twit[0] }}</div>
+  <div class="col-md-4">{{ twit[2] }}</div>
+  <div class="col-md-4"><a href='/edit_twit?id={{ twit[1] }}'> edit </a><a
+  href='/delete_twit?id={{ twit[1] }}'> delete </a></div>
+</div> 
+{% endfor %}
+</div>
+
+{% endblock %}