[Django] #18166: Allow the formset class to contribute kwargs to form instances
Django
-----------------------------+----------------------------------
Reporter: tevans | Owner: nobody
Type: New feature | Status: new
Component: Forms | Version: SVN
Severity: Normal | Keywords: forms formset kwargs
Triage Stage: Unreviewed | Has patch: 1
Easy pickings: 0 | UI/UX: 0
-----------------------------+----------------------------------
When we use a formset, each form is instantiated by the method
BaseFormSet._construct_forms(), which is called from
BaseFormSet.__init__()
_construct_forms() allows for additional kwargs to be passed through to
the individual form constructor, but BaseFormSet.__init__() does not
provide any mechanism for kwargs to be passed through to the
_construct_forms() call.
Also, we may not be able to supply a static unchanging list of kwargs that
should be supplied to each form constructor - the kwargs we want to pass
may depend upon the specific instance of the form being instantiated.
I propose the following changes:
Add a form_kwargs argument to BaseFormSet.__init__(). This would be stored
on self, and consumed in BaseFormSet._construct_forms()
Add a method, BaseFormSet._kwargs_for_form(self, i). This method would be
called for each form instantiated, passing the index of the form within
the formset. The return value of this method would be merged with the
form_kwargs supplied in BaseFormSet.__init__() and used to instantiate the
form.
With these changes, a user could add additional constructor arguments to
all forms by passing in form_kwargs to the formset constructor, and could
add additional constructor arguments to specific forms by implementing
_kwargs_for_form on a derived BaseFormSet class.
(I found it strange, when BaseFormSet was written, it was clearly intended
to be able to pass kwargs to the forms - _construct_form() allows for it,
there just is not the plumbing to do so. I worked around this by
redefining - copy/pasting - the _construct_forms() method in my derived
BaseFormSet class)
Patch doesn't have tests or doc changes, will add if this idea gets
traction.
Cheers
Tom
--
Ticket URL: <https://code.djangoproject.com/ticket/18166>
Django <https://code.djangoproject.com/>
The Web framework for perfectionists with deadlines.
Django
Type: New feature | Status: new
Component: Forms | Version: SVN
Keywords: forms formset | Triage Stage:
kwargs | Unreviewed
Has patch: 1 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Changes (by tevans):
* needs_better_patch: => 0
* needs_tests: => 0
* needs_docs: => 0
Comment:
Hmm, wiki markup that turns !__init!__ into __init__ is less than useful
for Python discussion :/
--
Ticket URL: <https://code.djangoproject.com/ticket/18166#comment:1>
Django
Type: New feature | Status: new
Component: Forms | Version: SVN
Keywords: forms formset | Triage Stage:
kwargs | Unreviewed
Needs tests: 1 | Patch needs improvement: 0
Changes (by tevans):
* needs_docs: 0 => 1
* needs_tests: 0 => 1
--
Ticket URL: <https://code.djangoproject.com/ticket/18166#comment:2>
Django
Type: New feature | Status: new
Component: Forms | Version: SVN
Keywords: forms formset | Triage Stage:
kwargs | Unreviewed
Has patch: 1 | Needs documentation: 1
Needs tests: 1 | Patch needs improvement: 0
Old description:
When we use a formset, each form is instantiated by the method
{{{_construct_forms()}}} allows for additional kwargs to be passed through
to the individual form constructor, but {{{BaseFormSet.__init__()}}} does
not provide any mechanism for kwargs to be passed through to the
{{{_construct_forms()}}} call.
Also, we may not be able to supply a static unchanging list of kwargs that
should be supplied to each form constructor - the kwargs we want to pass
may depend upon the specific instance of the form being instantiated.
I propose the following changes:
{{{BaseFormSet._construct_forms()}}}
within the formset. The return value of this method would be merged with
the form_kwargs supplied in {{{BaseFormSet.__init__()}}} and used to
instantiate the form.
With these changes, a user could add additional constructor arguments to
all forms by passing in form_kwargs to the formset constructor, and could
add additional constructor arguments to specific forms by implementing
_kwargs_for_form on a derived BaseFormSet class.
(I found it strange, when {{{BaseFormSet}}} was written, it was clearly
intended to be able to pass kwargs to the forms - {{{_construct_form()}}}
allows for it, there just is not the plumbing to do so. I worked around
this by redefining - copy/pasting - the {{{_construct_forms()}}} method in
my derived {{{BaseFormSet}}} class)
Patch doesn't have tests or doc changes, will add if this idea gets
traction.
Cheers
Tom
--
Comment (by lrekucki):
Replying to [comment:1 tevans]:
> Hmm, wiki markup that turns !__init!__ into __init__ is less than useful
for Python discussion :/
You can use formatting: !{{{ __init__ }}} will show as {{{__init__}}}.
There's both live preview and a preview button.
--
Ticket URL: <https://code.djangoproject.com/ticket/18166#comment:3>
Django
Type: New feature | Status: new
Component: Forms | Version: SVN
Keywords: forms formset | Triage Stage:
kwargs | Unreviewed
Has patch: 1 | Needs documentation: 1
Needs tests: 1 | Patch needs improvement: 0
Comment (by akaariai):
Just as an idea: how about defining a new method:
{{{
def get_single_form(self, i, defaults):
"""
Override me to have total control over the single forms.
"""
return self.form(**defaults)
}}}
and use that instead of self.form() in the _construct_form() method. This
would be more powerful and easier to implement.
--
Ticket URL: <https://code.djangoproject.com/ticket/18166#comment:4>
Django
Type: New feature | Status: new
Component: Forms | Version: SVN
Keywords: forms formset | Triage Stage:
kwargs | Unreviewed
Has patch: 1 | Needs documentation: 1
Needs tests: 1 | Patch needs improvement: 0
Comment (by tevans):
Replying to [comment:4 akaariai]:
> Just as an idea: how about defining a new method:
> {{{
> def get_single_form(self, i, defaults):
> """
> Override me to have total control over the single forms.
> """
> return self.form(**defaults)
> }}}
> and use that instead of self.form() in the _construct_form() method.
This would be more powerful and easier to implement.
Yes, I like that. I would like to also keep the idea of being able to
contribute to a form's kwargs without defining a {{{BaseFormSet}}}
subclass, eg by passing them to {{{BaseFormSet.__init__}}}.
I should get some time this w/e to re-roll the patch.
--
Ticket URL: <https://code.djangoproject.com/ticket/18166#comment:5>
Django
Type: New feature | Status: new
Severity: Normal | Resolution:
Keywords: forms formset kwargs | Triage Stage: Accepted
Changes (by anonymous):
* needs_better_patch: 0 => 1
* stage: Unreviewed => Accepted
Comment:
Agreed, a method for implementing this is a good idea, but please let's
skip the redundant 'simple' prefix, just call it `get_form`.
--
Ticket URL: <https://code.djangoproject.com/ticket/18166#comment:6>
Django
Type: New feature | Status: new
Severity: Normal | Resolution:
Keywords: forms formset kwargs | Triage Stage: Accepted
Has patch: 1 | Needs documentation: 1
Comment (by jezdez):
Oops that was me.
--
Ticket URL: <https://code.djangoproject.com/ticket/18166#comment:7>
Django
Reporter: tevans | Owner: sergei-
| maertens
Type: New feature | Status: assigned
Component: Forms | Version: master
Severity: Normal | Resolution:
kwargs |
Has patch: 1 | Needs documentation: 1
Easy pickings: 0 | UI/UX: 0
Changes (by sergei-maertens):
* owner: nobody => sergei-maertens
* status: new => assigned
--
Ticket URL: <https://code.djangoproject.com/ticket/18166#comment:8>
Django
Reporter: tevans | Owner: sergei-
| maertens
Type: New feature | Status: assigned
Component: Forms | Version: master
Severity: Normal | Resolution:
Keywords: forms formset | Triage Stage: Accepted
kwargs |
Has patch: 1 | Needs documentation: 1
Easy pickings: 0 | UI/UX: 0
Comment (by sergei-maertens):
I'll have a go at this
--
Ticket URL: <https://code.djangoproject.com/ticket/18166#comment:9>
Django
Reporter: tevans | Owner: sergei-
| maertens
Type: New feature | Status: assigned
Component: Forms | Version: master
Severity: Normal | Resolution:
Keywords: forms formset | Triage Stage: Accepted
kwargs |
Needs tests: 0 | Patch needs improvement: 0
Changes (by sergei-maertens):
* needs_better_patch: 1 => 0
* needs_tests: 1 => 0
* needs_docs: 1 => 0
--
Ticket URL: <https://code.djangoproject.com/ticket/18166#comment:10>
Django
Reporter: tevans | Owner: sergei-
| maertens
Component: Forms | Version: master
Severity: Normal | Resolution: fixed
Keywords: forms formset | Triage Stage: Accepted
kwargs |
Has patch: 1 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Comment (by Russell Keith-Magee <russell@…>):
In [changeset:"fe21fb810a1bd12b10c534923809423b5c1cf4d7" fe21fb81]:
{{{
#!CommitTicketReference repository=""
revision="fe21fb810a1bd12b10c534923809423b5c1cf4d7"
Merge pull request #4757 from sergei-maertens/ticket_18166
Fixed #18166 -- Added ability to pass kwargs to the form constructor in a
formset.
}}}
--
Ticket URL: <https://code.djangoproject.com/ticket/18166#comment:12>
Django
Reporter: tevans | Owner: sergei-
| maertens
Type: New feature | Status: closed
Component: Forms | Version: master
Severity: Normal | Resolution: fixed
Keywords: forms formset | Triage Stage: Accepted
kwargs |
Has patch: 1 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Changes (by Sergei Maertens <sergei@…>):
* status: assigned => closed
* resolution: => fixed
Comment:
In [changeset:"238e2ac3690755d0e6c2dfca815e2b6f84a47f6e" 238e2ac3]:
{{{
#!CommitTicketReference repository=""
revision="238e2ac3690755d0e6c2dfca815e2b6f84a47f6e"
Fixed #18166 -- Added form_kwargs support to formsets.
By specifying form_kwargs when instantiating the formset, or overriding
the `get_form_kwargs` method on a formset class, you can pass extra
keyword arguments to the underlying `Form` instances.
Includes tests and documentation update.
}}}
--
Ticket URL: <https://code.djangoproject.com/ticket/18166#comment:11>