application.py

#Used code from Authenication and Authorization: Oauth and the dicussion forum

from flask import Flask, render_template, request, redirect, jsonify, url_for, flash
from sqlalchemy import create_engine, asc
from sqlalchemy.orm import sessionmaker
from database_setup import Base, Category, Item
from flask import session as login_session
import random
from oauth2client.client import flow_from_clientsecrets
from oauth2client.client import FlowExchangeError
import httplib2
import json
from flask import make_response
import requests, string
from dicttoxml import dicttoxml

app = Flask(__name__)

CLIENT_ID = json.loads(open('client_secrets.json', 'r').read())['web']['client_id']


# Connect to Database and create database session
engine = create_engine('sqlite:///catalog.db')
Base.metadata.bind = engine

DBSession = sessionmaker(bind=engine)
session = DBSession()


# Create anti-forgery state token
@app.route('/login')
def showLogin():
    state = ''.join(random.choice(string.ascii_uppercase + string.digits)
                    for x in xrange(32))
    login_session['state'] = state
    # return "The current session state is %s" % login_session['state']
    return render_template('login.html', STATE=state)


@app.route('/gconnect', methods=['POST'])
def gconnect():
    # Validate state token
    if request.args.get('state') != login_session['state']:
        response = make_response(json.dumps('Invalid state parameter.'), 401)
        response.headers['Content-Type'] = 'application/json'
        return response
    # Obtain authorization code
    code = request.data

    try:
        # Upgrade the authorization code into a credentials object
        oauth_flow = flow_from_clientsecrets('client_secrets.json', scope='')
        oauth_flow.redirect_uri = 'postmessage'
        credentials = oauth_flow.step2_exchange(code)
    except FlowExchangeError:
        response = make_response(json.dumps('Failed to upgrade the authorization code.'), 401)
        response.headers['Content-Type'] = 'application/json'
        return response

    # Check that the access token is valid.
    access_token = credentials.access_token
    url = ('https://www.googleapis.com/oauth2/v1/tokeninfo?access_token=%s' % access_token)
    h = httplib2.Http()
    result = json.loads(h.request(url, 'GET')[1])
    # If there was an error in the access token info, abort.
    if result.get('error') is not None:
        response = make_response(json.dumps(result.get('error')), 500)
        response.headers['Content-Type'] = 'application/json'

    # Verify that the access token is used for the intended user.
    gplus_id = credentials.id_token['sub']
    if result['user_id'] != gplus_id:
        response = make_response(json.dumps("Token's user ID doesn't match given user ID."), 401)
        response.headers['Content-Type'] = 'application/json'
        return response

    # Verify that the access token is valid for this app.
    if result['issued_to'] != CLIENT_ID:
        response = make_response(json.dumps("Token's client ID does not match app's."), 401)
        print "Token's client ID does not match app's."
        response.headers['Content-Type'] = 'application/json'
        return response

    stored_credentials = login_session.get('credentials')
    stored_gplus_id = login_session.get('gplus_id')
    if stored_credentials is not None and gplus_id == stored_gplus_id:
        response = make_response(json.dumps('Current user is already connected.'),200)
        response.headers['Content-Type'] = 'application/json'
        return response

    # Store the access token in the session for later use.
    login_session['credentials'] = credentials.access_token
    login_session['gplus_id'] = gplus_id

    # Get user info
    userinfo_url = "https://www.googleapis.com/oauth2/v1/userinfo"
    params = {'access_token': credentials.access_token, 'alt': 'json'}
    answer = requests.get(userinfo_url, params=params)

    data = answer.json()

    login_session['username'] = data['name']
    login_session['picture'] = data['picture']
    login_session['email'] = data['email']

    output = ''
    output += '<h1>Welcome, '
    output += login_session['username']
    output += '!</h1>'
    output += '<img src="'
    output += login_session['picture']
    output += ' " style = "width: 300px; height: 300px;border-radius: 150px;-webkit-border-radius: 150px;-moz-border-radius: 150px;"> '
    flash("you are now logged in as %s" % login_session['username'])
    print "done!"
    return output

    # DISCONNECT - Revoke a current user's token and reset their login_session


@app.route('/gdisconnect')
def gdisconnect():
        # Only disconnect a connected user.
    credentials = login_session.get('credentials')
    if credentials is None:
        response = make_response(json.dumps('Current user not connected.'), 401)
        response.headers['Content-Type'] = 'application/json'
        return response
    access_token = login_session.get('credentials')
    url = 'https://accounts.google.com/o/oauth2/revoke?token=%s' % access_token
    h = httplib2.Http()
    result = h.request(url, 'GET')[0]

    if result['status'] == '200':
        # Reset the user's sesson.
        del login_session['credentials']
        del login_session['gplus_id']
        del login_session['username']
        del login_session['email']
        del login_session['picture']

        response = make_response(json.dumps('Successfully disconnected.'), 200)
        response.headers['Content-Type'] = 'application/json'
        return response
    else:
        # For whatever reason, the given token was invalid.
        response = make_response(json.dumps('Failed to revoke token for given user.', 400))
        response.headers['Content-Type'] = 'application/json'
        return response

#JSON APIs to view Category Information
@app.route('/catalog/<int:category_id>/JSON')
def categoryJSON(category_id):
    items = session.query(Item).filter_by(category_id = category_id).all()
    return jsonify(Items=[i.serialize for i in items])


@app.route('/catalog/<int:category_id>/<int:item_id>/JSON')
def itemJSON(category_id, item_id):
    item = session.query(Item).filter_by(id = item_id).one()
    return jsonify(item = item.serialize)

@app.route('/catalog/JSON')
def categoriesJSON():
    categories = session.query(Category).all()
    return jsonify(categories= [r.serialize for r in categories])

#XML API endpoints
@app.route('/catalog/<int:category_id>/XML')
def categoryXML(category_id):
    items = session.query(Item).filter_by(category_id = category_id).all()
    return dicttoxml({'Items':[i.serialize for i in items]})

@app.route('/catalog/<int:category_id>/<int:item_id>/XML')
def itemXML(category_id, item_id):
    item = session.query(Item).filter_by(id = item_id).one()
    return dicttoxml(item.serialize)

@app.route('/catalog/XML')
def categoriesXML():
    categories = session.query(Category).all()
    obj = {'categories': [r.serialize for r in categories]}
    return dicttoxml(obj)
	
#Show all Categories
@app.route('/')
@app.route('/catalog/')
def showCategories():
    categories = session.query(Category).all()
    items = session.query(Item).all()
    items = items[::-1]
    if 'username' not in login_session:
	return render_template('publiccatalog.html', categories = categories, items = items[:9])
    else:
	return render_template('logincatalog.html', categories = categories, items = items[:9])

#Show category items
@app.route('/catalog/<int:category_id>/')
def showItems(category_id):
    categories = session.query(Category).all()
    category = session.query(Category).filter_by(id = category_id).one()
    items = session.query(Item).filter_by(category_id = category.id).all()
    count = len(items)
    if 'username' not in login_session:
        return render_template('publicitems.html', items = items, categories = categories, category = category, count = count)
    else:
        return render_template('loginitems.html', items = items, categories = categories, category = category, count = count)

@app.route('/catalog/<int:category_id>/<int:item_id>/')
def showOneItem(category_id,item_id):
    item = session.query(Item).filter_by(id = item_id).one()
    if 'username' not in login_session:
        return render_template('publicitemdescription.html',item = item)
    else:
        return render_template('loginitemdescription.html',item = item)

#Add new item to category
@app.route('/catalog/<int:category_id>/new/', methods=['GET', 'POST'])
def newItem(category_id):
    category = session.query(Category).filter_by(id = category_id).one()
    categories = session.query(Category).all()
    items = session.query(Item).filter_by(category_id = category.id).all()
    count = len(items)
    if 'username' not in login_session:
        return render_template('publicitems.html', items = items, categories = categories, category=category.name, count = count)
    if request.method == 'POST':
        newItem = Item(name=request.form['name'], description=request.form['description'], category_id=category.id)
        session.add(newItem)
        session.commit()
        return redirect(url_for('showItems', category_id=category_id))
    else:
        return render_template('newitem.html', category_id = category_id)

# Edit item
@app.route('/catalog/<int:category_id>/<int:item_id>/edit', methods=['GET', 'POST'])
def editItem(category_id,item_id):
    if 'username' not in login_session:
        return redirect('/login')
    editedItem = session.query(Item).filter_by(id=item_id).one()
    category = session.query(Category).filter_by(id=category_id).one()
    if request.method == 'POST':
        if request.form['name']:
            editedItem.name = request.form['name']
        if request.form['description']:
            editedItem.description = request.form['description']
        session.add(editedItem)
        session.commit()
        return redirect(url_for('showItems', category_id=category_id))
    else:
        return render_template('edititem.html', item=editedItem)

# Delete item
@app.route('/catalog/<int:category_id>/<int:item_id>/delete', methods=['GET', 'POST'])
def deleteItem(category_id, item_id):
    if 'username' not in login_session:
        return redirect('/login')
    itemToDelete = session.query(Item).filter_by(id=item_id).one()
    if request.method == 'POST':
        session.delete(itemToDelete)
        session.commit()
        return redirect(url_for('showItems', category_id=itemToDelete.category_id))
    else:
        return render_template('deleteitem.html', item=itemToDelete)


if __name__ == '__main__':
  app.secret_key = 'super_secret_key'
  app.debug = True
  app.run(host = '0.0.0.0', port = 8000)