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Question

I have a web application in a flask API where users leave comments and star ratings(1-5). I will use those ratings for a movie recommender algorithm. I want to allow for one user to leave one comment to each movie, but I don't want for them to leave more than one comment. If they have a comment I want for them to edit that comment.

My comment table:

id	content	rating	commenter_id	movie_id
1	Wery good movie	5	1	1
2	I like this movie	5	1	1

So basically I don't want to allow what is happening where in this case id=2

@app.route("/movie/<int:movie_id>", methods=['GET', 'POST'])
@login_required
def movie(movie_id):
    movie = Movie.query.get_or_404(movie_id)
    comments = Comment.query.filter_by(movie_id=movie_id).all()
    current_user_comments = Comment.query.filter_by(movie_id=movie_id,commenter_id=current_user.id).first()
    if current_user_comments:
        print('Has')
    else:
        print('Has not')
    form = CommentForm()
    if form.validate_on_submit():
        comment= Comment(content=form.content.data, rating=request.form.get("rating"), commenter_id=current_user.id, movie_id=movie_id)
        db.session.add(comment)
        db.session.commit()
        flash('Comment has been added!', 'success')
        return redirect(request.url)
    return render_template('movie.html', title=movie.title, movie=movie,comments=comments,form=form)

If user has comment on spesific movie I print 'Has' if he has not I print 'Has not'. Now I have to figure out how to make him edit already existing comment instead of creating new.

Answer 1

Where you print() "Has" you create the CommentForm using the syntax

form = CommentForm(obj=curren_user_comments)

and in the else branch

form = CommentForm()

This will present the user with his earlier comment and enable changing the comments if he has previous comments, else he will be presented with a page to add a new comment.

In the update you will want to change the code too. In case you have existing current_user_comments you want to update this, not create a new one of course. You may want to limit the fields the user can update to eg the actual comments text and the rating.