Hello all,
I'm a newbie like billf and I'm trying to do some things, but I don't
see an easy way of doing them, maybe you can help me.
I have a question on Tim's solution of creating a form in the view and
replicating it in the action: how would I load values on the forms
fields ? Would I have to go something like "<input text = 'name'
value='{{= name}}'>" and pass the necessary values when rendering ?
Also, I think repeating the form structure in the code could create
problems later on, such as de-synchronizing the view and the action
(adding a field in one of them and forgetting to add on the other one
or even typos would cause a lot of hard to detect trouble).
I could bare building the form using the helpers in the action,
loading them with the values (like form.load(record)) and passing them
on to the view, but the only ways I know for loading values into the
fields are either creating the form with SQLFORM(table, record) (which
doesn't allow me to customize it at all) or putting them into the
_value attribute for each field (which becomes a lot of coding because
I can't use the SQLFORM.accepts for automatically inserting and
updating the db), is there any other way ?
As of now, I'm actually thinking of writing the form.load(record) and
form.load(dictionary) myself. Would that be repeating any feature I'm
not aware of ?
Thanks,
Deodoro Filho
On 8 out, 21:23, billf <[EMAIL PROTECTED]> wrote:
> Tim - thanks for all the info. As a Python newbie I have never heard
> of FormEncode.
>
> Given what I know at this point I think I prefer to follow up your
> first solution.
>
> The first thing I didn't understand was why the form.accepts() needed
> the name of the form in your view? This got me digging and html.py
> and sqlhtml.py (great to see all the arguments available) shed a lot
> of light but there are still a lot of blanks as to how the whole thing
> works.
>
> I have boiled all my questions down to: "Can someone please explain
> the sequence of events embodied in the following?"
>
> form=SQLFORM(db.recipe)
> if form.accepts(request.vars,session):
> response.flash="Successful" (or something)
> return dict(form=form)
>
> My version with holes is:
> form=SQLFORM(db.recipe) > sqlhtml.py to create form from db.recipe
>
> form.accepts(request.vars,session) > sqlhtml.py then calls
> FORM.accepts() in html.py; if return is true then goes on to update db
> > html.py
> FORM.accepts() implemented by DIV.accepts()
>
> Hole: I can't work out what is happening in DIV.accepts(). I'm
> assuming there is some "first time" check - "we haven't any
> request.vars yet" - that maybe uses the session but I can't see where
> anything is stored in the session or how it uses the form name. Any
> help greatly appreciated.
>
> Hole: I assume that if form.accepts() returns false then it does not
> necessarily mean that there are errors - it could just be that the
> form hasn't been output yet. Is that correct?
>
> Apologies if the questions are a bit vague.
>
> Bill
>
> On Oct 8, 10:12 pm, Timothy Farrell <[EMAIL PROTECTED]> wrote:
>
> > I should also note that while this method has the advantage of using
> > web2py's built-in data-verifiers, if you use FormEncode, you can get a
> > bit more power and flexibility for about the same amount of code.
> > Verifying the form I posted with FormEncode would look like:
>
> > import formencode
>
> > class FormValidator(formencode.Schema):
> > name = validators.Regex(r'[A-Za-z0-9-\.\']{4,40}')
> > county = validators.OneOf(COUNTIES)
> > td = validators.Regex(r'on', if_missing='', if_empty='')
>
> > try:
> > data = FormValidator(allow_extra_fields =
> > True).to_python(dict(request.vars))
> > # Validation succeeded, continue
> > except formencode.Invalid, e:
> > # Validation failed, see messages in e
> > message = e.message
>
> > Bummer (for FormEncode) that form.accepts is so much cleaner than the
> > FormEncode version. Maybe I'll wrap it into a nice pretty package.
>
> > -tim
>
> > Timothy Farrell wrote:
> > > Bill,
>
> > > I crossed this bridge a few weeks ago. I, like you, don't dig the whole
> > > presentation logic in the controller. However, it is still reasonable
> > > to build a "form" in the controller for logical data-handling purposes.
> > > Here's what I did:
>
> > > # Build our form
> > > form=FORM(INPUT(_type="text", _name="name"
> > > , requires=IS_MATCH('[A-Za-z0-9-\.\']{4,40}'))
> > > ,SELECT(_name="county"
> > > ,requires=IS_IN_SET(COUNTIES) )
> > > ,INPUT(_type="checkbox", _name="td"
> > > ,requires=IS_NULL_OR(IS_MATCH('on')))
> > > )
> > > # If the submit validates, act accordingly
> > > if form.accepts(request.vars, formname="polinfo"):
> > > # process passed data here...
>
> > > Once I made "form", I never passed it to the view, instead I used this
> > > form:
>
> > > <form method="POST"
> > > id="polinfo"
> > > action="">
> > > <div>
> > > <label for="name">Name:</label>
> > > <input type="text"
> > > name="name"
> > > id="name" />
> > > </div>
> > > <div>
> > > <label for="county">County:</label>
> > > <select name="county"
> > > id="county">
> > > <option></option>
> > > <option value="Oklahoma">
> > > Oklahoma
> > > </option>
> > > <option value="Other">
> > > Other
> > > </option>
> > > <option value="Tulsa">
> > > Tulsa
> > > </option>
> > > </select>
> > > </div>
> > > <div>
> > > <label for="td">TD:</label>
> > > <input type="checkbox"
> > > id="TD"
> > > name="td" />
> > > <input type="hidden"
> > > name="_formname" value="polinfo" />
> > > </div>
> > > </form>
>
> > > Notice that I included a hidden field "_formname". This is the trick
> > > that you need to get it to work.
>
> > > There you go, a happy marriage of both the ease of web2py forms while
> > > maintaining proper MVC separation.
>
> > > -tim
>
> > > billf wrote:
>
> > >> I am trying to get to grips with forms as part of an attempt to re-
> > >> engineer an existing Java webapp using web2py.
>
> > >> I like the ability to generate a form automatically. I especially
> > >> like the benefit that accepts() gives. However, I can foresee many
> > >> situations where the auto-generated form is not what I want in terms
> > >> of layout. I have looked a little at widgets but I don't think that
> > >> allows the ability to manage the overall form layout. I know that I
> > >> can use the HTML building objects but I don't want presentation logic
> > >> in the controller.
>
> > >> It seems to me (at the moment) that the ideal would be the ability,
> > >> when necessary, to design a form manually in a view using html/css but
> > >> be able to utilise the form.accepts() logic in the controller.
>
> > >> I'm tempted to think that this is already possible. If I code:
>
> > >> form=SQLFORM(db.recipe)
> > >> if form.accepts(request.vars,session):
> > >> whatever...
>
> > >> ...I am assuming that this creates a form based on db.recipe and
> > >> populates the form.vars with request.vars and does the rest
> > >> (validation, updating db). I just need to ensure that the
> > >> request.vars names are those expected by the form?
>
> > >> Before I spend a lot of time on this am I heading up a dead-end?
>
> > >> Bill
>
> > tfarrell.vcf
> > < 1KViewDownload
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