Binding model data to a formset without POST

[Rob Groves]

Hi All,
I am new to Django and am enjoying it very much.  Excellent documentation, 
tutorials, and general environment to work in.  Good job Django developers!

I have a question on binding data to a ModelFormset.  I have looked 
extensively and not seen this particular issue covered before.

I have a ModelFormset that I send to a template for custom rendering so I 
can present the fields in a controlled tabular format.  The ultimate goal 
is to use CSS to create a red bounding box around any fields with 
validation errors and to set the "title" attribute of those input fields so 
that the user can see what errors were generated  by hovering over the red 
bounded field.  This presents a nice clean interface when there are 
errors.  It all works great, with one annoyance if the model data starts 
out with values that will generate validation errors (i.e. missing required 
data).  

I initially call the view with a GET, which creates the forms and populates 
the form fields.  Since the data is not bound to forms at this point, I 
can't validate and set the errors.  In order to validate the fields and set 
the table error borders, I have to submit the form using POST to bind the 
data, validate the form and generate the errors which ultimately set an 
error_class for styling the table.  This means that I have to "save" the 
from from my form page to get the table style I want.

What I really want is to instantiate a ModelFormset, setting the instance, 
but then to bind the data present in the instance and set errors by sending 
is_valid() to the formset before rendering (i.e. on initial page rendering 
with the GET, so no POST data).  It seemed to me that there should simply 
be a bind_instance() function for all ModelFormsets that contain an 
instance.  I looked and didn't find that.  Eventually, I just decided to 
bind the data myself manually using the following helper function:

# helper functions
def bind_formset(formset):
bindData={}
# add management form data
bindData[formset.get_default_prefix()+"-TOTAL_FORMS"]=str(formset.
management_form['TOTAL_FORMS'].value())
bindData[formset.get_default_prefix()+"-INITIAL_FORMS"]=str(formset.
management_form['INITIAL_FORMS'].value())
bindData[formset.get_default_prefix()+"-MIN_NUM_FORMS"]=str(formset.
management_form['MIN_NUM_FORMS'].value())
bindData[formset.get_default_prefix()+"-MAX_NUM_FORMS"]=str(formset.
management_form['MAX_NUM_FORMS'].value())
for form in formset:
if form.instance:
for fieldName,fieldValue in form.fields.iteritems():
try:
bindData[form.add_prefix(fieldName)]=getattr(form.
instance,fieldName)
except:
# this is an added field, not derived from the model
pass
newFormset=formset.__class__(bindData,instance=formset.instance,
  queryset=formset.queryset, error_class=
formset.error_class)
return newFormset

This works!  My question... Is this a reasonable approach?  Or did I just 
miss the obvious way of doing this?

Thanks for any help!

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Re: Binding model data to a formset without POST

[Rob Groves]

Thanks for the reply Collin, and thanks for the warning about this being 
more complicated than it seemed at first.  I later discovered that I needed 
to set the hidden fields that contain the foreign and instance keys as 
well.  For completeness, the below code is working for me given the fact 
that I only have simple fields.

# helper functions
def bind_formset(formset):
"""
Bind initial data to a formset
"""
if formset.is_bound:
# do nothing if the formset is already bound
return formset

bindData={}
# the formset.get_default_prefix() and form.add_prefix() methods add in 
the 
# dict keys that uniquely identify the various form fields with the 
individual 
# instance data

# add formset management form data
bindData[formset.get_default_prefix()+"-TOTAL_FORMS"]=str(formset.
management_form['TOTAL_FORMS'].value())
bindData[formset.get_default_prefix()+"-INITIAL_FORMS"]=str(formset.
management_form['INITIAL_FORMS'].value())
bindData[formset.get_default_prefix()+"-MIN_NUM_FORMS"]=str(formset.
management_form['MIN_NUM_FORMS'].value())
bindData[formset.get_default_prefix()+"-MAX_NUM_FORMS"]=str(formset.
management_form['MAX_NUM_FORMS'].value())
for form in formset:
if form.instance:
# field data, get these values from the instance
for fieldName,fieldValue in form.fields.iteritems():
try:
bindData[form.add_prefix(fieldName)]=getattr(form.
instance,
 fieldName)
except AttributeError:
# this is an added field (i.e. DELETE), not derived 
from the
# model, do nothing with it, since we are only binding 
instance
# data to the form
pass
# hidden field data, get these from the field initial values set
# when the form was created
for field in form.hidden_fields():
bindData[form.add_prefix(field.name)]=field.field.initial
# create a new bound formset by passing in the bindData dict, this looks
# to the formset constructor like a request.POST dict 
newFormset=formset.__class__(bindData,instance=formset.instance,
 error_class=formset.error_class)
return newFormset



On Thursday, January 22, 2015 at 8:36:08 PM UTC-5, Collin Anderson wrote:
>
> Hi,
>
> Interesting. I've never heard of someone wanting to show validation errors 
> on the initial data when the page first loads.
>
> I have however wanted to manually bind data to a form before. Last time I 
> checked it's not super trivial, because you could for instance have a 
> SplitDateTimeWidget which actually expects _two_ keys in the bound data.
>
> If you're just doing basic fields, that should work. If you're doing 
> anything more complicated, it might make sense to run the validation more 
> by hand. If you could call field.clean() on the less raw data you could 
> skip widgets and prefixes all together.
>
> Collin
>
> On Tuesday, January 20, 2015 at 8:06:06 AM UTC-5, Rob Groves wrote:
>>
>> Hi All,
>> I am new to Django and am enjoying it very much.  Excellent 
>> documentation, tutorials, and general environment to work in.  Good job 
>> Django developers!
>>
>> I have a question on binding data to a ModelFormset.  I have looked 
>> extensively and not seen this particular issue covered before.
>>
>> I have a ModelFormset that I send to a template for custom rendering so I 
>> can present the fields in a controlled tabular format.  The ultimate goal 
>> is to use CSS to create a red bounding box around any fields with 
>> validation errors and to set the "title" attribute of those input fields so 
>> that the user can see what errors were generated  by hovering over the red 
>> bounded field.  This presents a nice clean interface when there are 
>> errors.  It all works great, with one annoyance if the model data starts 
>> out with values that will generate validation errors (i.e. missing required 
>> data).  
>>
>> I initially call the view with a GET, which creates the forms and 
>> populates the form fields.  Since the data is not bound to forms at this 
>> point, I can't validate and set the errors.  In order to validate the 
>> fields and set the table error borders, I have to submit the form using 
>> POST to bind the data, validate the form and generate the errors which 
>> ultimately set an error_class for styling the table.  This means that I 
>> have to "save" the from from my form page to get

Re: Django error report not being sent through email

[Rob Groves]

I'm not sure if it is a typo... but your have:

*  EMAIL_HOST = 'stmp.comp.nus.edu.sg '*Should 
that be:
*  EMAIL_HOST = 'smtp.comp.nus.edu.sg '*

On Saturday, September 19, 2015 at 7:49:56 AM UTC-4, Xin Ji wrote:
>
> I'm using apache + django + mod_wsgi to serve my app.
> My apache version is 2.4.7 and my django version is 1.8.4
>
> My django settings are:
>  * DEBUG=False*
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
> *  ADMINS = [  ('username','user...@comp.nus.edu.sg '),  
> ]  MANAGERS = [  ('username','user...@comp.nus.edu.sg '),  
> ]  MIDDLEWARE_CLASSES = (  ...  
> 'django.middleware.common.BrokenLinkEmailsMiddleware',  )  EMAIL_HOST = 
> 'stmp.comp.nus.edu.sg '  EMAIL_PORT = 25  
> EMAIL_HOST_USER = 'username'  EMAIL_HOST_PASSWORD = 'password'*
>
> When I ran the server, I got this error on the website(This page uses the 
> django 500.html template.):
> Server Error *(500)* 
>
> There's been an error. It's been reported to the site administrators via 
> email and should be fixed shortly. Thanks for your patience.
>
> But I *didn't receive* any email about the error report.
>
> What's wrong with my configurations?
>

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Re: Does anyone use Django on bluehost? "Cant find fcgi module" error on line 9 .

[Rob Groves]

I am using Django on bluehost.  I suspect that the issue you are seeing is 
that Django1.9 has stopped supporting fcgi.  I found that out when I tried 
to upgrade from 1.8 a while back.  I think you can probably copy over the 
fcgi module from the Django 1.8 release, but I haven't tried that.  I just 
stayed at 1.8, since it is still under support.  I figured I'd deal with it 
later when I have to move to 1.9.

On Thursday, April 7, 2016 at 11:28:53 AM UTC-4, django...@gmail.com wrote:
>
> We are using django on bluehost. Installed python, flup, django, and using 
> a postgres server. Every time I try and run fcgi it gives an error that the 
> module does not exist. Verified with bluehost that it is on our server. Put 
> it in the htaccess file Help anyone
>

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