Flask: Not Found 在服务器上找不到请求的 URL。 如果您手动输入 URL，请检查您的拼写并重试

Question

Error "Not Found The requested URL was not found on the server. If you entered the URL manually please check your spelling and try again." occurs when pressing menu-item 'Redactiehulp'. How can I solve this?

When pressing "Add", "Login" or "Register", the correct screens are properly shown.

My app.py is:

from ast import Str
from enum import unique
from turtle import st
from typing_extensions import Self
from flask import Flask, render_template, request, redirect, url_for, flash
from datetime import datetime
from logging import DEBUG
from forms import RegistrationForm, LoginForm
from flask_sqlalchemy import SQLAlchemy

app = Flask(__name__)

app.logger.setLevel(DEBUG)

feedback=[]

def store_feedback(url):
    feedback.append(dict(
        url=url,
        user='Looneycorn',
        date=datetime.utcnow()
    ))

@app.route('/')
@app.route('/index')
def index():
    return render_template('index.html')

@app.route('/add', methods=['GET','POST'])
def add():
    if request.method == "POST":
        url = request.form['url']
        store_feedback(url)
        app.logger.debug('stored feedback:' + url)
        flash("Your feedback : " + url)
        return redirect(url_for('index'))
    return render_template('add.html')

@app.route("/register", methods = ['GET', 'POST'])
def register():
    form = RegistrationForm()
    if form.validate_on_submit():
        flash('Account created')
        return redirect(url_for('login'))
    if form.errors:
        flash('Validation Errors: ' + str(form.errors))
        app.logger.error('Validation error(s):\n' + str(form.errors))
    return render_template('register.html', title='Register', form = form)

@app.route('/resulttekst/<nieuwetekst>')
def resulttekst(nieuwetekst):
    return 'Resultaat: %s' % nieuwetekst

@app.route('/redactiehulp', methods = ['GET', 'POST'])
def redactiehulp():
    app.logger.debug('Redactiehulp, ingevoerde tekst:' + invoertekst)
    if request.method == "POST":
        invoertekst = request.form['invoertekst']
        newtekst = '111-' + invoertekst + '-222'
        return redirect(url_for('resulttekst', nieuwetekst = newtekst))
    else:
        invoertekst = request.args.get('invoertekst')
        newtekst = '333-' + invoertekst + '-444'
        return redirect(url_for('resulttekst', nieuwetekst = newtekst))
    return render_template('redactiehulp.html')

@app.route('/login', methods = ['GET', 'POST'])
def login():
    form = LoginForm()
    if form.validate_on_submit():
            flash('Logged in!')
            return redirect(url_for('index'))
        else:
            flash('Login unsuccessful')
    return render_template('login.html', title='Login', form = form)

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

PS. redactiehulp.html is:

{% extends "base.html" %}

{% block title %}
Redactiehulp
{% endblock %}

{% block content %}

    <section>
        <form action="" method = "post">
            <h2>Redactiehulp</h2>
            <p>Voer de te redigeren text in en druk vervolgens op 'Redigeer' voor het resultaat:</p>
            <p>
                <input type="text" name="invoertekst">
            </p>
            <p>
                <button type="submit">Redigeer</button>
            </p>
        </form>
    </section>

{% endblock %}

{% block sidebar %}
{% endblock %}

When pressing "Add", "Login" or "Register", the correct screens are properly shown. However, when "Redactiehulp" is clicked the following error is shown: "Not Found The requested URL was not found on the server. If you entered the URL manually please check your spelling and try again."

add.html, login.html and register.html but also redactiehulp.html, are all in the same \templates folder.

Answer 1

You code looks like good, just make sure template name should be match same you mentioned. Otherwise Try to use two scenario for change route.

<a href="{{ url_for('redactiehulp') }}">Go To Redactiehulp</a>

And

<a href="/redactiehulp">Go To Redactiehulp</a>