From 63507c66bf05080bf87d97bef2b85a216c04d8d6 Mon Sep 17 00:00:00 2001
From: Martin Mares <mj@ucw.cz>
Date: Fri, 11 Oct 2024 20:02:27 +0200
Subject: [PATCH] Students can leave courses if they have no posts
Closes #98.
---
owl/course.py | 36 +++++++++++++++++++++++++++++++++++-
owl/templates/course.html | 5 +++++
owl/templates/leave.html | 21 +++++++++++++++++++++
3 files changed, 61 insertions(+), 1 deletion(-)
create mode 100644 owl/templates/leave.html
diff --git a/owl/course.py b/owl/course.py
index 43f333d..72deb1a 100644
--- a/owl/course.py
+++ b/owl/course.py
@@ -5,7 +5,7 @@ import datetime
from decimal import Decimal
from flask import Flask, render_template, request, make_response, g, request_tearing_down, redirect, url_for, flash
from flask_wtf import FlaskForm
-from sqlalchemy import select, and_, or_, false
+from sqlalchemy import select, and_, or_, false, delete
import sqlalchemy.sql.functions as func
from sqlalchemy.orm import joinedload, aliased
from typing import Optional, Tuple
@@ -215,6 +215,40 @@ def enroll_commit(course: db.Course) -> None:
sess.commit()
+# Leaving
+
+class LeaveConfirmForm(FlaskForm):
+ pass
+
+
+@app.route('/c/<sident>/<cident>/leave', methods=('GET', 'POST'))
+def leave(sident: str, cident: str) -> str:
+ app.course_init(sident, cident)
+ sess = db.get_session()
+
+ err = None
+ if g.is_teacher:
+ err = 'Teachers are not allowed to leave their courses.'
+ else:
+ if sess.scalar(
+ select(db.Post)
+ .join(db.Topic)
+ .filter(or_(db.Post.target_uid == g.uid, db.Post.author_uid == g.uid))
+ .filter(db.Topic.course == g.course)
+ .limit(1)
+ ):
+ err = 'You cannot leave, because you already have posts in this course.'
+
+ form = LeaveConfirmForm()
+ if err is None and form.validate_on_submit():
+ sess.execute(delete(db.Enroll).where(and_(db.Enroll.uid == g.uid, db.Enroll.course == g.course)))
+ sess.commit()
+ flash(f'You left the course {g.course.name}.', 'info')
+ return redirect(url_for('index'))
+
+ return render_template('leave.html', form=form, error=err)
+
+
# Topics
@app.route('/c/<sident>/<cident>/<tident>/', methods=('GET', 'POST'))
diff --git a/owl/templates/course.html b/owl/templates/course.html
index afd17f7..07e2168 100644
--- a/owl/templates/course.html
+++ b/owl/templates/course.html
@@ -84,4 +84,9 @@
{% else %}
<p>The course is empty. Come back in a couple of millifortnights.
{% endif %}
+ {% if not g.is_teacher %}
+ <nav class=buttons>
+ <a class=button href='{{ url_for('leave', sident=g.course.semester.ident, cident=g.course.ident) }}'>Leave the course</a>
+ </nav>
+ {% endif %}
{% endblock %}
diff --git a/owl/templates/leave.html b/owl/templates/leave.html
new file mode 100644
index 0000000..6ad1719
--- /dev/null
+++ b/owl/templates/leave.html
@@ -0,0 +1,21 @@
+{% set title = g.course.name %}
+{% extends "base.html" %}
+{% block body %}
+ <h2>{{ g.course.name }}</h2>
+
+ {% if error %}
+ <p class="flash flash-error">{{ error }}
+ {% else %}
+ <p>Please confirm that you want to leave this course.
+ {% endif %}
+
+ <nav class=buttons>
+ {% if not error %}
+ <form method="POST" action="?">
+ {{ form.csrf_token }}
+ <input class=danger type=submit value='Leave'>
+ </form>
+ {% endif %}
+ <a class=button href='{{ url_for('course_index', sident=g.course.semester.ident, cident=g.course.ident) }}'>Back to the course</a>
+ </nav>
+{% endblock %}
--
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