Unable to delete row in datastore

Question

I am new to Google App Engine and datastore so please be patient :)

My code below is trying to ask for user inputs, either entering or deleting an entry, and the results will be shown directly in a table on the same page. When I tried to delete a particular entry in the datastore, the row does not get deleted in the datastore and sometimes new rows with empty data are added. Why does this happen?

    class Events(ndb.Model):
        name = ndb.StringProperty()
        desc = ndb.StringProperty()

    class Promote(webapp2.RequestHandler):
        def get(self):
            query = ndb.gql("SELECT * "
                            "FROM Events "
                            )
            template_values = {"events" : query,}
            template = jinja_environment.get_template('promote.htm')
            self.response.out.write(template.render(template_values))

        def post(self):
            event = Events(name = self.request.get('name'), desc = self.request.get('desc'))
            event.put()
            self.redirect('/promote')

    class Delete(webapp2.RequestHandler):
        def post(self):
            event = ndb.Key('Events', self.request.get('eventname'))
            event.delete()
            self.redirect('/promote')


    app = webapp2.WSGIApplication([('/', Main),
                                   ('/publicsearch', PublicSearch),
                                   ('/promote', Promote),
                                   ('/delete',Delete)],
                                  debug=True)

This is the html code

    <div class="jumbotron">
          <div class = "container">
             <form action="/promote" method="post">
                <fieldset>
                  <div class="row-fluid">
                  <p> Promote your event here! </p>
                  <div class="row-fluid">
                  <div class="span6">
                  <p> Name of event: <br>
                  <textarea class="input-block-level" name="name" rows="1" cols = "50"> </textarea></p>
                  <p> Event description: <br>
                  <textarea class="input-block-level" name="desc" rows="3" cols = "50"> </textarea></p>
                  <p><input type="submit" value="Submit">
                </div>
            </div>
        </div>
    </div>
</div>

    <h4> Events feed </h4>
    <table class="table table-bordered table-striped">
        <thead>
            <tr>
                <th width="30%">Name</th>
                <th width="60%">Description</th>
                <th>Delete Event</th>
            </tr>
        </thead>
        <tbody>
            {% for event in events %}
            <tr>
                <td>{{ event.name }} </td>
                <td>{{ event.desc }}  </td>
                <td>                    
                  <form action="/delete" method="post">
                    <input type="hidden" name="eventkey" value="{{ event.key.urlsafe() }}">
                    <input type="submit" value="Delete">
                  </form>
                </td>
            </tr>
                {% endfor %}
            </tbody>
        </table>
    </div>

Thanks!

Answer 1

The key is not based on the event name, because you haven't specified any key when creating the events: they'll just use a numeric id.

The better thing to do here would be to put the actual key in the hidden input: you can use the urlsafe method to output a string that can be used in templates.

<input type="hidden" name="eventkey" value="{{ event.key.urlsafe() }}">

and in the view:

event = ndb.Key(urlsafe=self.request.get('eventkey'))