How to solve 405 Method Not Allowed (flask) [closed] - python

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I'm keep getting the 405 error, I've changed my code following the other related posts but still not working.
routes.py
from flask import render_template, redirect, flash, url_for, abort, request
from flask_login import current_user, login_user, logout_user, login_required
from flask import Flask
import views.model as mod
app = Flask(__name__)
#app.route('/')
def index():
mod.check_database_init()
return render_template("index.html")
#app.route('/login',methods = ['GET','POST'])
def login():
if(request.method == 'POST'):
print("post")
name = request.form['username']
password = request.form['password']
print(name, password)
return redirect(url_for("index"))
else:
return render_template("login.html")
#app.route('/register', methods = ['GET','POST'])
def register():
return render_template("register.html")
login.html
{% include "header.html" %}
<title>Login</title>
<form action="/login" method="POST">
<label>Username</label>
<input type = "text" placeholder = "username" name="username" required>
<label>Password</label>
<input type = "password" placeholder="password" name = "password" required>
<input type="submit">
<p>
Don't have an acoount? Click me to create a new account
</p>
</form>
Back to homepage
I tried this method, https://stackoverflow.com/a/62464826/13239458, it works but I don't know what went wrong in the code above.
server.py
from flask import Flask
from flask_login import LoginManager
import views.routes as rou
import views.database as db
app = Flask(__name__)
app.add_url_rule('/', view_func=rou.index)
app.add_url_rule('/login', view_func=rou.login)
app.add_url_rule('/register', view_func=rou.register)
if __name__ == "__main__":
app.run(host='127.0.0.1', debug = True)
UPDATE
I just change method type into GET (in login.html) and there will be no error and I can see the input from the console, so I think the login method cannot accept the POST method but I have no idea why is that.

Just find out the issue, I created 2 app instances, I move the instantiation into another file then import it, everything works!

You have not included:
if __name__ == '__main__':
app.run(debug=True)
in the end of routes.py

Related

Flask-Login #login-required decorator not redirecting to login page after session has expired

UPDATE
It appears that the Flask redirect (response code 302) below is being passed as the response to the _dash-update-component request:
b'<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN">\n<title>Redirecting...</title>\n<h1>Redirecting...</h1>\n<p>You should be redirected automatically to target URL: /login. If not click the link.'
This explains the SyntaxError thrown by dash_renderer below, so this led me to add the following in server.py:
#server.after_request
def check_response(response):
redirecting = 'Redirecting...' in response.get_data().decode('utf-8')
dash_response = request.path=='/_dash-update-component'
return make_response('', 204) if redirecting and dash_response else response
Now I can emulate a Dash-like PreventUpdate by returning a "204 No-Content" response to the dash component, but then I am not receiving the additional request for the redirect back to the login page. Commenting out the after_request function and then tracking the requests seen by before_request, it's actually shown that the login() route is invoked and render_template('login.html') is returned, but it's simply not rendered in the browser....
ORIGINAL POST BELOW
I've spent the better part of the last few days attempting to overhaul our login procedures to add some quality of life update and modifications. For the purposes of this question, I'm interested in logging out our users after a certain period of inactivity in the main Dash application.
My approach was to register routes for our Login page, and then point a Flask route for /dashapp to the response returned by app.index() where app points to the Dash application. Once they are logged into the Dash application, I have a before_request decorator that will update the session modified attribute and the session expiration (5 seconds for the purposes of testing). I've also applied the #login_required decorator to this invoked function, so that login_manager.unauthorized_handler is invoked if the user is no longer authenticated when triggering the before_request decorator. I think my logic is sound here, but I am still having issues which I will describe below.
I am able to login my users and redirect them to the main Dash application at /dashapp, and I can use the application without issues. Now when I wait the 5 seconds to allow for the session to expire, clicking on a component in my Dash application that triggers a dash callback produces the following error in the console:
dash_renderer.v1_7_0m1602118443.min.js:20 SyntaxError: Unexpected token < in JSON at position 0
I'm aware that some function is expecting a JSON response, and has apparently received an HTML response instead, but I can't pin down what that is. It's also preventing my redirection back to the login page that I expected to be invoked when the user was no longer authenticated and triggered the before_request decorator.
My code structure is below (not that config.py is simply my SQL connection):
application.py
from dash.dependencies import Input, Output, State
import dash_core_components as dcc
import dash_html_components as html
from server import app, server as application, User, login_manager
from flask_login import logout_user, current_user, login_user, login_required
from flask import session, redirect, render_template, url_for, request
from views import main
app.layout = html.Div([
dcc.Location(id='url', refresh=False),
html.Div(id='page-content')
])
#application.route('/login')
def login():
return render_template('login.html')
#application.route('/login', methods=['POST'])
def login_post():
if current_user.is_authenticated:
return redirect('/dashapp')
user = User.query.filter_by(username=request.form['username']).first()
#Check if user exists
if user:
#Check if password is correct
if user.password==request.form['password']:
login_user(user, remember=False)
return redirect('/dashapp')
#login_manager.unauthorized_handler
def unauthorized():
if request.path!='/login':
return redirect('/login')
#application.route('/logout')
#login_required
def logout():
logout_user()
return redirect('/login')
#application.route('/dashapp')
#login_required
def main_page():
return app.index()
#app.callback(
Output('page-content', 'children'),
[Input('url', 'pathname')])
def display_page(pathname):
if current_user.is_authenticated:
content = main.get_layout()
else:
content = dcc.Location(pathname='/login', id='redirect-id')
return content
if __name__ == '__main__':
app.run_server()
views/login.html
<html>
<head>
<title>Flask Intro - login page</title>
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<link href="static/bootstrap.min.css" rel="stylesheet" media="screen">
</head>
<body>
<div class="container">
<h1>Please login</h1>
<br>
<form action="" method="post">
<input type="text" placeholder="Username" name="username" value="{{
request.form.username }}">
<input type="password" placeholder="Password" name="password" value="{{
request.form.password }}">
<input class="btn btn-default" type="submit" value="Login">
</form>
{% if error %}
<p class="error"><strong>Error:</strong> {{ error }}
{% endif %}
</div>
</body>
</html>
server.py
import dash, os, datetime
from flask_login import LoginManager, UserMixin, current_user, login_required
from config import connection_string
import dash_bootstrap_components as dbc
from credentials import db, User as base
from flask import session, g, redirect, url_for, request, flash, render_template
import flask
external_stylesheets = [dbc.themes.BOOTSTRAP]
app_flask = flask.Flask(__name__)
app = dash.Dash(
__name__,
server=app_flask,
external_stylesheets=external_stylesheets,
update_title=None,
url_base_pathname='/'
)
app.title = 'Login Testing Interface'
server = app_flask
app.config.suppress_callback_exceptions = True
server.config.update(
SECRET_KEY=os.urandom(12),
SQLALCHEMY_DATABASE_URI=connection_string,
SQLALCHEMY_TRACK_MODIFICATIONS=False
)
db.init_app(server)
#Setup the LoginManager for the server
login_manager = LoginManager()
login_manager.init_app(server)
login_manager.login_view = 'login'
#Create User class with UserMixin
class User(UserMixin, base):
def get_id(self):
return self.user_id
#Reload the user object
#login_manager.user_loader
def load_user(user_id):
return User.query.get(user_id)
#server.before_request
#login_required
def check_authentication():
session.permanent = True
server.permanent_session_lifetime = datetime.timedelta(seconds=5)
session.modified = True
g.user = current_user
main.py
from dash.dependencies import Input, Output, State
import dash_core_components as dcc
import dash_html_components as html
import dash_bootstrap_components as dbc
from flask_login import current_user
from server import app, server
def get_layout():
return html.Div([
dcc.Location(id='url-main', refresh=False),
dbc.Button('Click me', id='test-click', n_clicks_timestamp=0),
html.Div(id='testing')
])
#app.callback(
Output('testing', 'children'),
[Input('test-click', 'n_clicks_timestamp')])
def update_test_div(clicks):
return f'Last clicked: {clicks}'
credentials.py
from flask_sqlalchemy import SQLAlchemy
from config import engine
db = SQLAlchemy()
db.Model.metadata.reflect(engine)
class User(db.Model):
__table__ = db.Model.metadata.tables['my_sql_table_with_user_details']
Thank you in advance for any guidance here!
I suggest writing your login and login post route as a single fuunction
#app.route('/login', methods=['POST','GET'])
def login():
if current_user.is_authenticated :
return redirect('/')
if request.method == 'POST':
user_name = request.form.get('username')
password_entered =request.form.get('password')
present_user=User.query.filter_by(username=user_name).first()
if present_user.password == password_entered:
login_user(present_user)
next_page= request.args.get('next')
print(next_page)
return redirect(next_page) if next_page else redirect('/')
else:
flash('Incorrect Password',category='danger')
return render_template('user_login.html')
else:
return render_template('user_login.html')
If you redirected from the login_required function to the Login page,
you might notice that the link /url on top says
/login?next=%2FpathofFunction
When we write
next_page= request.args.get('next')
We get the remaining URL after ?next and then redirect the user to where it came from

Taking data from drop-down menu using flask

I'm completely new to flask, and really am completely lost with how to approach this. I've looked into other SO questions but I can't seem to get this working regardless.
I have a form as such:
<form class="teamSelection" method="POST" action="/submitted">
<select class="teamForm" id="teamDropdownSelector" type="text" name="teamDropdown" placeholder="Select A Team">
<option disabled selected>Select a game</option>
<option id="WatfordVSManchester Utd" value="">Watford VS Manchester Utd</option>
</select>
<input class="btn" type="submit" value="submit">
</form>
and my flask as so:
from flask import Flask
app = Flask(__name__)
#app.route("/submitted")
def hello():
return "hello world"
The goal is to take the content of the selected/submitted dropdown item, pass this to the flask file where I then use the team names to scrape information about the match. However at the moment I can't even seem to get the POST of the form to work and am at a complete loss. I appreciate this is a pretty vague and open-ended question, but I seriously don't know how else to figure this out.
Should I instead use jquery to detect when the dropdown has changed and use AJAX to send a POST to somehow call the script and pass the values into it?
Any help would be greatly appreciated.
EDIT
I thought I put this in the original post, but must have forgot.
I am currently running an apache localhost server, and am working with flask via pycharm. All I've done at the moment is install the flask package in pycharm, and haven't set any of it up like I've seen in some tutorials do when running from the command line. I assumed this step wasn't necessary, as I already have a server up and running with apache?
When it comes to backend stuff like this I really have no idea, so apologies if that's a stupid assumption.
I've changed the flask to:
from flask import Flask
app = Flask(__name__)
#app.route("/submitted", methods=['POST'])
def hello():
with open("newTest.csv", mode="w+") as file:
fileWriter = csv.writer(file)
fileWriter.writerow(['Time', 'HomeTeam', 'AwayTeam'])
file.close()
The reason being as I can see if this script is actually being called, if it is it will make a new csv file called newTest. After running the webpage and submitting no new csv file appears, so this script isn't being run, meaning it's likely due to me not configuring flask correctly?/The assumption that apache was enough was incorrect?
You have just to tell the flask method to accept POST request and to read parameters from the request
Example:
from flask import Flask, request
app = Flask(__name__)
#app.route("/submitted", methods=['POST'])
def hello():
myvariable = request.form.get("teamDropdown")
... your code ...
return "hello world"
So, your question is not about flask, but about fopen - you have to add a full file path including directory path script_dir = path.dirname(path.abspath(__file__)).
Flask script (modified for launching in my local copy of project):
from flask import Flask, render_template, request
import csv
from os import path
app = Flask(__name__)
script_dir = path.dirname(path.abspath(__file__))
#app.route ("/")
def index():
return render_template("index.html")
#app.route("/submitted", methods=["GET", "POST"])
def hello():
if request.method == "GET":
return render_template("index.html")
filefullpath = script_dir + '//newTest.csv'
with open(filefullpath, mode="w+") as file:
fileWriter = csv.writer(file)
fileWriter.writerow(['Time', 'HomeTeam', 'AwayTeam'])
file.close()
return "hello world"
index.html (in folder "/templates")
<!DOCTYPE html>
<html>
<head>
<title></title>
</head>
<body>
Test
<br>
<form class="teamSelection" method="POST" action="/submitted">
<select class="teamForm" id="teamDropdownSelector" type="text" name="teamDropdown" placeholder="Select A Team">
<option disabled selected>Select a game</option>
<option id="WatfordVSManchester Utd" value="">Watford VS Manchester Utd</option>
</select>
<input class="btn" type="submit" value="submit">
</form>
</body>
</html>
Modify your code as:
from flask import Flask
app = Flask(__name__)
#app.route("/submitted", methods=['POST'])
def hello():
return request.form['teamDropdown']
Please let me know if that helps.

Cannot add comment to SQL db in python Flask app

I am new to programming and have setup a small website with a comments section on pythonanywhere.com, relaying heavily on their tutorial. But when I post a comment in the form, the comment is not added to the database and for some reason the program redirects me to the index page (the intention is to redirect to stay on the same page)
Any suggestions as to what I might be doing wrong would be greatly appreciated!
The pyhthon code:
import random
from flask import Flask, request, session, redirect, url_for, render_template, flash
from flask.ext.sqlalchemy import SQLAlchemy
from werkzeug.routing import RequestRedirect
app = Flask(__name__)
app.config["DEBUG"] = True
SQLALCHEMY_DATABASE_URI = "mysql+mysqlconnector://{username}:{password}#{hostname}/{databasename}".format(
username="username",
password="password",
hostname="hostname",
databasename="majaokholm$majaokholm",
)
app.config["SQLALCHEMY_DATABASE_URI"] = SQLALCHEMY_DATABASE_URI
app.config["SQLALCHEMY_POOL_RECYCLE"] = 299
db = SQLAlchemy(app)
class Comment(db.Model):
__tablename__ = "comments"
id = db.Column(db.Integer, primary_key=True)
content = db.Column(db.String(4096))
#app.route("/")
def index():
return render_template("index_page.html")
#app.route('/post', methods=["GET", "POST"])
def post():
if request.method == "GET":
return render_template("post_page.html", comments=Comment.query.all())
comment = Comment(content=request.form["contents"])
db.session.add(comment)
db.session.commit()
return redirect(url_for('post'))
and the form from the HTML template:
<form action="." method="POST">
<textarea class="form-control" name="contents" placeholder="Enter a
comment"></textarea>
<input type="submit" value="Post comment">
</form>
Thanks a lot in advance!
Currently, the action="." in the form actually points to the root of the current directory, which for /post happens to be just / and thus points to the index.
It's always better to use action="{{ url_for('your_target_view') }}" instead.
get rid of action=".", you can use action=""

How to print output using only a POST Method?

How can I print something like this:
{
username = admin
email = admin#localhost
id=42
}
With only using a method = ['POST'] and without using render_template?
PS: I already made it run with ['GET']
Here's my code:
from flask import Flask, jsonify, request
app = Flask(__name__)
#app.route('/', methods=['POST'])
def index():
if request.method == 'POST':
return jsonify(username="admin",
email="admin#localhost",
id="42")
else:
if request.method == 'POST':
return jsonify(username="admin",
email="admin#localhost",
id="42")
if __name__ == "__main__":
app.run()
And what I get is a 405 Method error.
Hey make sure your trailing stashes in your html are correct.
you may refer to : Flask - POST Error 405 Method Not Allowed and flask documentation : http://flask.pocoo.org/docs/0.10/quickstart/
this
<form action="/" method="post">
and this is same same but different
<form action="" method="post">
Accessing it without a trailing slash will cause Flask to redirect to the canonical URL with the trailing slash.
Given your error 405, I am suspecting that this is your problem. GET is fine, because you will just be redirected.
Try returning the form (as biobirdman said) on a GET request. Not sure why you need the request.method == 'POST' conditional statement. The parameter methods=['POST'] in the route should suffice.
Try this:
from flask import Flask, jsonify, request
app = Flask(__name__)
#app.route('/', methods=['POST'])
def index():
return jsonify(username="admin", email="admin#localhost", id="42")
#app.route('/', methods=['GET'])
def form():
return "<form action='/' method='POST'>" \
"<input type='submit'>" \
"</form>"
if __name__ == "__main__":
app.run()

Flask 405 Error

I keep getting this error when trying to insert some simple text into a db.
Method Not Allowed
The method is not allowed for the requested URL."
I'm moving from PHP to python so bear with me here.
The code is:
from flask import Flask, request, session, g, redirect, url_for, \
abort, render_template, flash
from flask.ext.sqlalchemy import SQLAlchemy
app = Flask(__name__)
app.config['SQLALCHEMY_DATABASE_URI'] = 'mysql://root:password#localhost/pythontest'
db = SQLAlchemy(app)
app = Flask(__name__)
#app.route('/justadded/')
def justadded():
cur = g.db.execute('select TerminalError, TerminalSolution from Submissions order by id desc')
entries = [dict(title=row[0], text=row[1]) for row in cur.fetchall()]
return render_template('view_all.html', entries=entries)
#app.route('/new', methods= "POST")
def newsolution():
if not request.method == 'POST':
abort(401)
g.db.execute('INSERT INTO Submissions (TerminalError, TerminalSolution, VALUES (?, ?)'
[request.form['TerminalError'], request.form['TerminalSolution']])
g.db.commit()
flash('Succesful')
return redirect(url_for('justadded'))
#app.route('/')
def index():
return render_template('index.html')
#app.route('/viewall/')
def viewall():
return render_template('view_all.html')
if __name__ == '__main__':
app.run()
And the html code for the form is:
<form action="/new" method="POST">
<input name="TerminalError" id="searchbar" type="text" placeholder="Paste Terminal error here...">
<input name="TerminalSolution" id="searchbar" type="text" placeholder="Paste Terminal solution here...">
<button type="submit" id="search" class="btn btn-primary">Contribute</button>
</form>
The error has nothing to do with inserting data into the database, it's the methods argument of your /new route.
Instead of this:
#app.route('/new', methods= "POST")
do this:
#app.route('/new', methods= ["POST"])
The list of valid methods needs to be given as an array.

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