GETting information and POSTing a form in Flask

Question

I am trying to create a page that lists all information about an entity, then allows the user to add notes about the entity. I am using Flask on Google App Engine (using the boilerplate written by Kamal Gill).

My question is two-part: a) how do I query information about an entity and then post information using a form? b) How do I pass in the entity information to the form, so it edits the entity?

Here's what I've got:

#model.py
class Providers(db.Model):
    """Provider Information DB"""
    pAgency = db.StringProperty()
    pSite = db.StringProperty()
    programName = db.StringProperty()
    pNotes = db.TextProperty()

#forms.py
class ProviderForm(wtf.Form):
    providerName = wtf.TextField()
    providerNote = wtf.TextAreaField('Add notes', validators=[validators.Required()])

within views.py

def list_addresses(agency):
  addrs = []
  addresses = db.Query(Providers).filter('pAgency =', agency).order('pAddress')
  for addr in addresses:
     addrs.append((addr.pAddress, addr.programName))
  return addrs

def add_notes(agency):
  form = ProviderForm()
  if form.validate_on_submit():
     notes = ProviderNotes(
             pNotes = form.providerNote.data)
     try:
       notes.put()
       return 'Worked'
     except:
       return redirect(url_for('list_provs'))
  return render_template('provider_notes.html', form=form, addrs=list_addresses(agency))

The url rules:

# Add notes
app.add_url_rule('/providers/<agency>', 'add_notes', view_func=views.add_notes, methods=['GET', 'POST'])

The HTML I have right now is like this:

<ul>
 <h1 id="">Provider Information</h1>
     {% for address in addrs %}
     <p>{{address}}</p>
        {% for prog in programs %}
          {% if prog != '' %}
           <li>{{prog}}</li>
          {% endif %}
        {% endfor %}
     <p>&nbsp;</p>
     {% endfor %}
</ul>
<form method="post" action="{{ url_for('list_addresses') }}">
{% for field in form %}
        <p>{{ field.label }}</p>
        <p>{{ field }}</p>
{% endfor %}
    <p>
        <button type="submit">Save notes</button>
    <a href="{{ url_for('list_provs') }}">Cancel</a>
    </p>
</form>

This results in a trace-back error:

Traceback (most recent call last):
File ".../src/packages/flaskext/gae_mini_profiler/profiler.py", line 303, in __call__
  result = self.app(environ, start_response)
File ".../src/packages/flask.zip/flask/app.py", line 1506, in wsgi_app
File ".../src/packages/flask.zip/flask/app.py", line 1504, in wsgi_app
File ".../src/packages/flask.zip/flask/app.py", line 1264, in full_dispatch_request
File ".../src/packages/flask.zip/flask/app.py", line 1262, in full_dispatch_request
File ".../src/packages/flask.zip/flask/app.py", line 1248, in dispatch_request
File ".../src/application/views.py", line 55, in add_notes
  return render_template('provider_notes.html', form=form, addrs=list_addresses(agency))
File ".../src/packages/flask.zip/flask/templating.py", line 123, in render_template
File ".../src/packages/flask.zip/flask/templating.py", line 107, in _render
File ".../src/packages/jinja2.zip/jinja2/environment.py", line 891, in render
File ".../src/application/templates/provider_notes.html", line 1, in top-level template code
  <form method="post" action="{{ url_for('add_notes') }}">
  BuildError: ('add_notes', {}, None)

This error happens only when add_notes() is given an argument.

I'm a beginner at python, so I've probably missed something very obvious. I know that the error stems from trying to create a form within a GET context, but I'm not really sure how to fix that. And I have no idea how to start working on my two big questions.

Thanks, and let me know if I should further clarify something!

Edit: I have been looking at this question on routing, but don't really understand it enough to tell if it would work for what I need to do.

Answer 1

You have to pass the agency parameter to the add_notes view while building the url:

<form method="post" action="{{ url_for('add_notes',agency='something') }}">