how to put data(id) in form (wtforms) and get it back on submit

Question

I am new to wtforms, so I`ll really appreciate any help.

I need to display books names and near each put "Delete" button. I`ve read wtforms crash course but I have no idea how to solve my problem with it.

So I decided to do it other way - my best idea is to render to template a dict with id and name and on submit return id, but I still can`t do it. Code examples are below.

It`s view.py

@application.route('/delete', methods=['GET', 'POST'])
def delete():
    books_lib = mydatabase.get_all_books()
    form = DeleteForm(request.form)
    if request.method == 'POST':
        delete_id = form.id.data
        mydatabase.del_book(delete_id)
        return render_template('delete.html', form = form, books_lib = books_lib)
    return render_template('delete.html', form = form, books_lib = books_lib)

It`s template

<!DOCTYPE html>
<html>
<body>
    <h2>book to delete</h2>
<form action="/delete" name="delete" method="POST">
    {% if books_lib %}
        {% for id, book in books_lib.items() %}
            <p>{{book}}:<input type="submit" value="Delete" id="{{id}}">
        {% endfor%}
    {% endif %}
</form>
</body>
</html>

It`s form

class DeleteForm(Form):
     book = TextField("Book name", [validators.Length(min=2, max=25)])
     id = HiddenField("id")

do you really need it to be a form to delete ? would you consider having a delete link instead next to each book ? — codegeek, Apr 23 '14 at 18:53

jwogrady · Accepted Answer · 2014-04-23T19:37:35.943

Here is how I do it.

TEMPLATE

<p><a href="{{ url_for('delete_post', url=post.url) }}">delete</a></p>

View

# delete a post
@app.route('/<path:url>/d')
@login_required
def delete_post(url):
    post = Post.get_post(url)
    if post is None:
        flash('post not found')
        return redirect(url_for('home'))
    db.session.delete(post)
    db.session.commit()
    Topic.update_counts()
    flash('Your post has been deleted')
    return redirect(url_for('index'))

the url_for is a Flask function that generates a url and binds it to a function.

Soooo.... in a nutshell.

template generates the delete path using the url_for function.
the delete function is called when you visit the page.
message flashes to template saying delete complete.

to answer your original question....

if you simply want to pass a list of ids to your template....

First, create the display function.

@app.route('/index')
def index():
    posts = Post.query.order_by(Post.pub_date.desc())  #SQLAlchemy query.
    return render_template('index.html', posts=posts) #sends all posts to template.

Now in your template you can generate a list of post.ids.

    {% for post in posts %}
        {{post.id})
    {% endfor %}

to add a delete link next to each item in your list use url_for.

{% for post in posts %}    
<p>{{post.id}) <a href="{{ url_for('delete_post', id=post.id) }}">delete</a></p>
{% endfor %}

In this case I use post id instead of the post.url to identify the specific post I want to delete, so don't forget to modify your @app.route in your delete function.

@app.route('/<int:id>/delete')

Notice this solution does not require a form. You only need a form if your want to do bulk deletes with check boxes.

@jwogrady http://stackoverflow.com/questions/165779/are-the-put-delete-head-etc-methods-available-in-most-web-browsers Isn't it bad practice to do GET based data modifications? — user805981, Mar 20 '16 at 05:04

how to put data(id) in form (wtforms) and get it back on submit

1 Answers1