[FE-discuss] Re: FormEncode

I think you wrote to the SQLObject list, but meant to write to the 
FormEncode list

Michel Thadeu wrote:
> Ian, after the recent thread about form validation I think to try
> FormEncode, I used and still use FunFormKit for my projects, I use the
> FFK form generation and I confess it limitates my possibilities.
> 
> I like the way htmlfill work, I tried to make a validator to a form
> with sucess, my only problem was when I try to use htmlfill. I will put
> my code on the end of message.
> 
> I must question you that are using FormEncode with Webware, what is the
> best way to work with the two packages? I think in a way:

Well, I'm still working out some of it (while trying not to make it too 
automatic, and in the process mysterious).  But here's more or less how 
an edit form for a database object works.  I'm realizing it's not that 
short... sigh.

One app works like this:

def setup(self):
     self.form_fields = self.request().fields()
     if (self.form_fields.get('id', 'new') != 'new'
         and not self.form_fields.get('submit')):
         # fill in defaults...
         python_data = self.schema.event_to_python(
             db.Event.get(int(self.form_fields['id'])))
         # note event_to_python is something I coded elsewhere
         self.form_fields = variabledecode.variable_encode(
             self.schema.from_python(python_data))
     result, rendered_form = self.form()
     if result is not None:
         # successful submission, again python_to_event coded elsewhere
         new_event = self.schema.python_to_event(result)
         self.redirect(...)

def form(self):
     fields = self.form_fields
     errors = {}
     if fields.has_key('submit'):
         try:
             del fields['submit'] # not part of the schema
             result = self.schema.to_python(
                 variabledecode.variable_decode(fields))
         except Invalid, e:
             errors = variabledecode.variable_encode(e.unpack_errors())
         else:
             return result, None
     # 'submit' is a hidden
     fields['submit'] = 'true'
     p = htmlfill.FillingParser(fields, errors=errors, use_all_keys=True)
     # I actually use ZPT to render the form, but not the defaults...
     p.feed(self.get_html())
     p.close()
     form = p.text()
     return None, form


> First I will check for errors in the writeHTML method, if the form was
> processed and there is an error, I will define an attribute with this
> error. If there is no error, I can call a formProcessed function...
> 
> Then I should write the content of the page, the form is part of the
> page (using self.write to write it). I want to trigger the page
> writing, I want to get the content before write and then parse it with
> htmlfill, filling default values and error messages. Does anyone know
> how can I trigger the page writing? I use a subclass of the Cheetah's
> Template, not Page.
> 
> Sorry any english mistake, my htmlfill try are the follow:
> 
> #:: FormEncode test...
> from validator.schema import Schema
> from validator import validators
> from validator import htmlfill
> 
> class MyValidator(Schema):
>   name=validators.String(not_empty=True)
>   age=validators.Int()
> 
> form='''\
> <form method="post">
> <table>
> <tr>
>   <td>Name: <form:error name="name"></td><td><input type="text"
> name="name"></td>
>   <form:iferror name="name">mndfnaofdas</form:iferror>
> </tr>
> <p><input type="submit" name="_action_send" value="Send Data"></p>
> </form>'''
> 
> userInput={'name':'michel', 'age':20}
> 
> errorDict={}
> try:
>   userInput=validators.to_python(MyValidator, userInput)
> except validators.Invalid, error:
>   errorDict=error.error_dict

I think this should be errorDict = error.unpack_errors(); especially if 
the form has nested items (though this one doesn't).  Otherwise it looks 
fine, except for the bug you found.

> parser=htmlfill.FillingParser(userInput, errors=errorDict)
> parser.feed(form)
> print parser.text()
> parser.close()
> 
> ...
> 
> I get the follow error:
> 
> Traceback (most recent call last):
>   File "teste.py", line 29, in ?
>     parser.feed(form)
>   File "/usr/lib/python2.3/site-packages/validator/htmlfill.py", line
> 68, in feed
>     HTMLParser.HTMLParser.feed(self, data)
>   File "/usr/lib/python2.3/HTMLParser.py", line 108, in feed
>     self.goahead(0)
>   File "/usr/lib/python2.3/HTMLParser.py", line 150, in goahead
>     k = self.parse_endtag(i)
>   File "/usr/lib/python2.3/HTMLParser.py", line 329, in parse_endtag
>     self.handle_endtag(tag.lower())
>   File "/usr/lib/python2.3/site-packages/validator/htmlfill.py", line
> 127, in handle_endtag
>     self.handle_end_iferror()
> TypeError: handle_end_iferror() takes exactly 2 arguments (1 given)
> 
> Thanks for any help!

I guess I haven't been using iferror, the formatter mostly works for me. 
  Anyway, that was just a bug, I committed a fix to it.

-- 
Ian Bicking  /  ia...@co...  /  http://blog.ianbicking.org