views.py 文件源码

def check_valid_user(f):
    @wraps(f)
    def decorated_function(*args, **kwargs):
        """
        Decorator to check if the user is allowed access to the app.

        If user is allowed, return the decorated function.
        Otherwise, return an error page with corresponding message.
        """
        if request.form:
            session.permanent = True
            # 1 hour long session
            app.permanent_session_lifetime = timedelta(minutes=60)
            session['course_id'] = request.form.get('custom_canvas_course_id')
            session['canvas_user_id'] = request.form.get('custom_canvas_user_id')
            roles = request.form['roles']

            if "Administrator" in roles:
                session['admin'] = True
                session['instructor'] = True
            elif 'admin' in session:
                # remove old admin key in the session
                session.pop('admin', None)

            if "Instructor" in roles:
                session['instructor'] = True
            elif 'instructor' in session:
                # remove old instructor key from the session
                session.pop('instructor', None)

        # no session and no request
        if not session:
            if not request.form:
                app.logger.warning("No session and no request. Not allowed.")
                return return_error('No session or request provided.')

        # no canvas_user_id
        if not request.form.get('custom_canvas_user_id') and 'canvas_user_id' not in session:
            app.logger.warning("No canvas user ID. Not allowed.")
            return return_error('No canvas uer ID provided.')

        # no course_id
        if not request.form.get('custom_canvas_course_id') and 'course_id' not in session:
            app.logger.warning("No course ID. Not allowed.")
            return return_error('No course_id provided.')

        # If they are neither instructor or admin, they're not in the right place

        if 'instructor' not in session and 'admin' not in session:
            app.logger.warning("Not enrolled as Teacher or an Admin. Not allowed.")
            return return_error('''You are not enrolled in this course as a Teacher or Designer.
            Please refresh and try again. If this error persists, please contact support.''')

        return f(*args, **kwargs)
    return decorated_function


# ============================================
# Web Views / Routes
# ============================================