Can you use a Django form multiple times in one view? - django

I have a Django view that uses one form multiple times. The form is just a boolean field form that is supposed to initialize to True but then the user can decide to uncheck the boxes or not.
The problem I'm having is that the all of the fields evaluate to True no matter what the user leaves checked. Is this a problem with using the same form multiple times, or did I mess something else up?
The form looks like this:
class DataTypeForm(forms.Form):
def __init__(self,*args,**kwargs):
section_label = kwargs.pop('section_label')
initial_value = kwargs.pop('initial_value')
super(DataTypeForm,self).__init__(*args,**kwargs)
self.fields['dataType'].label=mark_safe(section_label)
self.fields['dataType'].initial=initial_value
self.fields['dataType'].required=False
dataType = forms.BooleanField(required=False)
This is the view:
def Manual_Request(request):
form_dict = {}
arg_dict = {}
message = message = {'last_url':'Nominal_Request'}
if request.method == 'POST':
logger.info("Query submitted, beginning query results render for:")
form_NOM = DataTypeForm(request.POST or None,section_label="ENG_NOM",initial_value=True)
form_DDM = DataTypeForm(request.POST or None,section_label="SCI_DDM",initial_value=True)
form_RAW = DataTypeForm(request.POST or None,section_label="SCI_RAW",initial_value=False)
if form_NOM.is_valid():
NOM = form_NOM.cleaned_data['dataType']
arg_dict.update({'ENG_NOM':str(NOM)})
logger.info("ENG_NOM: {val}".format(val=NOM))
if form_DDM.is_valid():
DDM = form_DDM.cleaned_data['dataType']
arg_dict.update({'SCI_DDM':str(DDM)})
logger.info("SCI_DDM: {val}".format(val=DDM))
if form_RAW.is_valid():
RAW = form_RAW.cleaned_data['dataType']
arg_dict.update({'SCI_RAW':str(RAW)})
logger.info("SCI_RAW: {val}".format(val=RAW))
return Request_Results(request,args_dict)
else:
logger.info("Rendering query page")
form_NOM = DataTypeForm(section_label="ENG_NOM",initial_value=True)
form_DDM = DataTypeForm(section_label="SCI_DDM",initial_value=True)
form_RAW = DataTypeForm(section_label="SCI_RAW",initial_value=True)
form_dict.update({'form_NOM':...etc})
return render(request,'InterfaceApp/COMMRequest_Manual.html',form_dict)
Help much appreciated!

I haven't run your code, but my best guess is that yes, it's a problem with using the same form multiple times in the same view. The reason? All of your <input type="checkbox" name="..." ... /> tags will have the same name, 'dataType'. The user's browser knows nothing of your back-end, and will just send, for example, dataType=on&dataType=on as POST data for the three fields if two are checked and one is not.
Seeing the problem here? How is django supposed to know which of those dataType fields are for your NOM, DDM, or RAW forms? It can't know.
You should be able to solve this using form prefixes. In short, there's a kwarg that you can pass to a form's __init__() that will cause a prefix to be added to all of the form items in the rendered HTML. So, for example:
form_NOM = DataTypeForm(request.POST or None, section_label="ENG_NOM",
initial_value=True, prefix="NOM")
form_DDM = DataTypeForm(request.POST or None, section_label="SCI_DDM",
initial_value=True, prefix="DDM")
form_RAW = DataTypeForm(request.POST or None, section_label="SCI_RAW",
initial_value=False, prefix="RAW")
Hope that helps!

This is exactly what Django formsets are for. They allows you to create a set of the same type of form. It handles prefixes, and adds a management form so that Django doesn't get confused as to what data comes from what form.
https://docs.djangoproject.com/en/1.8/topics/forms/formsets/

Related

(Hidden field id) Select a valid choice. That choice is not one of the available choices. (Django)

I'm receiving this error when I try to submit two formsets. After I fill the form and click the save button, it gives the error:
(Hidden field id) Select a valid choice. That choice is not one of the available choices.
I'm trying to create dynamic form so that the user can add new sections and also new lectures inside the section when they click "Add" button. The adding new form function works well, I just have problem saving it to the database.
Views.py
def addMaterials(request, pk):
course = Course.objects.get(id=pk)
sections = CourseSection.objects.filter(course_id=pk)
materials = CourseMaterial.objects.filter(section__in=sections)
SectionFormSet = modelformset_factory(CourseSection, form=SectionForm, extra=0)
sectionformset = SectionFormSet(request.POST or None, queryset=sections)
MaterialFormSet = modelformset_factory(CourseMaterial, form=MaterialForm, extra=0)
materialformset = MaterialFormSet(request.POST or None, queryset=materials)
context = {
'course': course,
'sectionformset': sectionformset,
'materialformset': materialformset,
}
if request.method == "POST":
if all([sectionformset.is_valid() and materialformset.is_valid()]):
for sectionform in sectionformset:
section = sectionform.save(commit=False)
section.course_id = course.id
section.save()
for materialform in materialformset:
material = materialform.save(commit=False)
print(material)
material.section_id = section #section.id or section.pk also doesn't work
material.save()
return('success')
return render(request, 'courses/add_materials.html', context)
Forms.py
class SectionForm(forms.ModelForm):
class Meta:
model = CourseSection
fields = ['section_name', ]
exclude = ('course_id', )
class MaterialForm(forms.ModelForm):
class Meta:
model = CourseMaterial
fields = ['lecture_name', 'contents']
The second formset which is materialformset need the section id from the first formset hence why there is two loop in views.
Can someone help me to solve this. I'm not sure how to fix it.
This is the what I'm trying to do.
I'm new to django but I had to face with the same problem. My solution was to handle singularly each formset inside 'views.py'.
In the template.html, create a tag for each formset you have, than inside that tag put <input type="submit" name="form1">(Note that name is important and must be different with the respect of the form you are submitting).
Then in views.py, instead for writing if all([sectionformset.is_valid() and materialformset.is_valid()]), try like this:
if 'form1' in request.POST:
if sectionformset.is_valid():
sectionformset.save()
# other rows of your code
return('success')
if 'form2' in request.POST:
if materialformset.is_valid():
materialformset.save()
# etc. etc.

Django inline-formset ordering issue when editing

I am trying to use the Django inline-formset.
Forms should be displayed sorted by their order value which is correctly done when I request the form.
But if I change the order values and save, the first view is with the previous order (refresh does the trick)
forms:
class SlidesForm(forms.ModelForm):
order = forms.IntegerField(widget=forms.NumberInput())
background_image = forms.ImageField(widget=forms.FileInput(attrs={'class': 'custom-file-input'}), required=False)
text = forms.CharField(max_length=256, widget=forms.Textarea(attrs={'rows': 2, 'class': 'form-control'}), required=False)
class Meta:
model = SlideCarousel
fields = ['order', 'background_image', 'text']
views:
def management_form_general(request, city_slug):
city = City.objects.get(slug=city_slug)
SlideCarouselInlineFormSet = inlineformset_factory(City, SlideCarousel, form=SlidesForm, extra=0)
if request.method == 'POST':
carousel_formset = SlideCarouselInlineFormSet(request.POST, request.FILES, instance=city, queryset=city.slidecarousel_set.order_by("order"))
if carousel_formset.is_valid():
carousel_formset.save()
else:
carousel_formset = SlideCarouselInlineFormSet(instance=city, queryset=city.slidecarousel_set.order_by("order"))
return render(request, 'management/form/city_general.html', {'city': city, 'carousel_formset': carousel_formset})
Any idea what I am doing wrong ? Tried to reinstance the carousel_formset after the save but it seems nasty and it actually didn't work
Right now you're still returning the same queryset (already evaluated and ordered) in the formset. What you need is to get the data that you just saved and update the formset with it. I think that you have two options that should work.
Recreate the carousel_formset like you said. This might not be exactly what you want but it seems more likely than my second suggestion. You said you tried this and it didn't work. If your code looks the same as mine then you might want to skip this approach.
carousel_formset.save()
carousel_formset = SlideCarouselInlineFormSet(
instance=city,
queryset=city.slidecarousel_set.order_by("order"),
)
Usually, after I save a form(set) I would redirect to a success URL. In this case that would be the same path again.
carousel_formset.save()
return redirect(request.path)
A third option that I have no idea if it will work, but you could try for very little effort, would be to re-set the carousel_formset.queryset attribute.
carousel_formset.save()
carousel_formset.queryset = city.slidecarousel_set.order_by("order")

How to check which the fields of a form has been modified in Flask?

I am trying to figure out a way to check if there is any built-in Form method that would return true if the form has been modified in Flask/WTForms
I know that in Django Forms, we have that flexibility to use form.has_changed() method that would do exactly what i want.
I am trying to check if the form has been modified and if it is I would to do some database updates.
If anybody has any idea, please let me know about this or suggest the right approach to start with.
I haven't found any built-in Form methods, but here is my quirky approach how I check whether the form was changed, and which fields were changed.I'm just storing the whole original form in the additional StringField, and then comparing it with the new form. As I don't want this field to be displayed on the page, I'm changing it's style to style="visibility:hidden;display:none" in the html file
#app.route("/page", methods=["GET", "POST"])
def page(tag=None):
class Person(FlaskForm):
name = StringField("name")
age = StringField("name")
class Spouses(FlaskForm):
people = FieldList(FormField(JetsonForm), min_entries=0)
people_orig = StringField("people_orig")
submit = SubmitField("Submit")
data_from_database = get_data_from_database()
data = {'people': [], 'people_orig': json.dumps(data_from_database)}
for person_name in data_from_database:
data['people'].append(data_from_database[person_name])
form = Spouses(data=data)
people_orig_data = json.loads(form.people_orig.data)
people_new_data = dict()
for person in form.people:
people_new_data[person.name.data] = {
"name": persom.name.data,
"age": peron.age.data
}
if form.is_submitted():
for person_name in people_new_data:
for field in people_new_data[person_name]:
if people_new_data[person_name][field] != people_orig_data[cam][key]:
#update your database
return redirect(request.url)
return render_template("page.html",form=form)

submitting form results into db - django

i created a form to save a post into db for my blog project. I've designed index page. now i am tryin to create a form to create new posts. before that i was using ' manage.py shell'
here is my view :
def addpost(request):
form = addForm()
if request.method=="POST":
titleform = request.POST['title']
bodyform = request.POST['body']
checkform = request.POST['isdraft']
if form.is_valid():
n = Post(title = titleform, body = bodyform, isdraft=checkform)
n.save()
return HttpResponseRedirect('/admin/')
else:
pass
return render(request,'userside/add.html',{'form':form,})
my model.py:
class Post(models.Model):
title = models.CharField(max_length = 100)
body = models.TextField()
slug = AutoSlugField(populate_from='title',unique=True)
posted = models.DateField(auto_now_add=True)
isdraft = models.BooleanField()
def __unicode__(self):
return self.title
#permalink
def get_absolute_url(self):
return ('view_blog_post',None, {'postslug':self.slug})
class addForm(forms.Form):
title = forms.CharField(max_length=100)
body = forms.CharField(widget=forms.Textarea)
isdraft = forms.BooleanField()
if i submit form as 'isdraft' field is False(unchecked) ; it gives error like:
MultiValueDictKeyError at /admin/addpost/
"Key 'isdraft' not found in "
and if i submit the form as 'isdraft' field is True(checked) ; it gives nothing. just refreshing form. no adding data into db.
i am doing sth wrong..
thank you
edit : Dmitry Beransky's answer worked for checkbox error. but it still doesnt add any data into db. just refreshes the form.
The whole point of using a form is that it takes care of validation and cleaning, that is converting values to the proper data types. That's why you should be accessing form.cleaned_data rather than reques.POST, and you should be doing it inside the if form.is_valid() check.
Edit
I've just noticed that you're never passing request.POST to the form. So form.is_valid() will never be true.
Please go back and read the documentation about using a form in a view.
If a checkbox is not checked in your HTML form, it's name/value is not going to be included in the data that the browser sends to your server. Which meanst that the request.POST dictionary is not going to contain an entry for 'isdraft' which in turn will cause a key error when you try to read the isdraft value. A solution is to change the way you read the value from the posted data to:
checkform = request.POST.get('isdraft', False)
rather than throw an error if isdraft isn't found in the dictionary, this will set checkform to False (the default value in case of a missing key)
Maybe your form does not validate at all. Have you checked if your code even reaches those lines after the if form.is_valid() statement ? If they do, what you've done there is right and should create the db row for your new entry, though you could have used
Post.objects.create(....) , and that would have taken away the need for calling the method save().
Some points though:
instead of checking for request.POST , check for request.method == 'POST' , cause there might be a post which has an empty POST dict ( in case no arguments have been submitted ), in that case request.POST fails to provide the right check .
see the docs for more info : request.POST
instead of using request.POST['var_name'] , use request.POST.get('var_name', 'default_value') , cause doing this like request.POST['var_name'] might result in some exceptions ( in case for example the argument is not provided , like what happened for your checkform variable )
Try accessing those variables through form.cleaned_data
and finally , you don't need the else statement in the end , just use the indentation :)

Help understanding a Django view

I am trying to follow the code listed on https://github.com/alex/django-ajax-validation/blob/master/ajax_validation/views.py
I have been able to understand a small chunk of it. I have added comments stating my understanding of what is happening.
I would really appreciate some assistance on questions I listed in comments next to the lines I couldn't quite follow.
def validate(request, *args, **kwargs):
# I thing it is some sort of initializations but I cannot really understand what's happening
form_class = kwargs.pop('form_class')
defaults = {
'data': request.POST
}
extra_args_func = kwargs.pop('callback', lambda request, *args, **kwargs: {})
kwargs = extra_args_func(request, *args, **kwargs)
defaults.update(kwargs)
form = form_class(**defaults)
if form.is_valid(): #straightforward, if there is no error then the form is valid
data = {
'valid': True,
}
else:
# if we're dealing with a FormSet then walk over .forms to populate errors and formfields
if isinstance(form, BaseFormSet): #I cannot really understand what is BaseFromSet
errors = {}
formfields = {}
for f in form.forms: # I am guessing that this is for when there are multiple form submitted for validation
for field in f.fields.keys(): # I think he is looping over all fields and checking for error. what does add_prefix () return? and what is formfields[]?
formfields[f.add_prefix(field)] = f[field]
for field, error in f.errors.iteritems():
errors[f.add_prefix(field)] = error
if form.non_form_errors():
errors['__all__'] = form.non_form_errors() # what is the '__all__'?
else:
errors = form.errors
formfields = dict([(fieldname, form[fieldname]) for fieldname in form.fields.keys()])
# if fields have been specified then restrict the error list
if request.POST.getlist('fields'): # I am having a hard time understanding what this if statement does.
fields = request.POST.getlist('fields') + ['__all__']
errors = dict([(key, val) for key, val in errors.iteritems() if key in fields])
final_errors = {} # here the author of this code totally lost me.
for key, val in errors.iteritems():
if '__all__' in key:
final_errors[key] = val
elif not isinstance(formfields[key].field, forms.FileField):
html_id = formfields[key].field.widget.attrs.get('id') or formfields[key].auto_id
html_id = formfields[key].field.widget.id_for_label(html_id)
final_errors[html_id] = val
data = {
'valid': False or not final_errors,
'errors': final_errors,
}
json_serializer = LazyEncoder() # Why does the result have to be returned in json?
return HttpResponse(json_serializer.encode(data), mimetype='application/json')
validate = require_POST(validate) # a decorator that requires a post to submit
LazyEncoder
class LazyEncoder(JSONEncoder):
def default(self, obj):
if isinstance(obj, Promise):
return force_unicode(obj)
return obj
form_class = kwargs.pop('form_class')
This is simply pulling the keyword argument, form_class, that was passed in via the URL conf.
(r'^SOME/URL/$', 'ajax_validation.views.validate',
{'form_class': ContactForm}, # this keyword argument.
'contact_form_validate')
BaseFormSet is simply the formset class doing the work behind the scenes. When you don't know, search the source! grep -ri "baseformset" . It's an invaluable tool.
Take a look at at django.forms.formsets to see how formset_factory produces new "formset" classes based on the BaseFormSet, hence the factory part!
I am guessing that this is for when there are multiple form submitted for validation
Yes, that's exactly what a formset is for (dealing with multiple forms)
I think he is looping over all fields and checking for error. what does add_prefix () return? and what is formfields[]?
Yes, that would be looping through the field names.
add_prefix() is for prefixing form field names with a specific form. Because a formset repeats form elements multiple times, each field needs a unique prefix, such as 0-field1, 1-field1, etc.
formfields is just an empty dictionary defined a few lines above.
what is the 'all'?
__all__ is defined at the top of django.forms.forms
NON_FIELD_ERRORS = '__all__'
It's just what non field specific errors (such as constraints across 2 fields) are stored under in the errors dictionary as opposed to errors[fieldname].
I am having a hard time understanding what this if statement does.
The author has left a note:
# if fields have been specified then restrict the error list
if request.POST.getlist('fields'):
It's checking if you specified any specific fields to validate in your URLConf, this is not django but ajax_validation.
You can see that he's overwriting his errors dictionary based on only the fields specified, thus passing on the validation only for those fields.
errors = dict([(key, val) for key, val in errors.iteritems() if key in fields])
here the author of this code totally lost me.
The author has mapped a custom errors and fields dictionary to specific field names with prefixes, (as opposed to the usual FormSet with each form having its own errors dictionary, unaware of the formset itself) which he presumably uses in the AJAX response to validate all fields.
Normally, you can iterate over a formset and go through the errors on a form by form basis, but not so if you need to validate all of them through ajax.
The line pulling html_id should be straight forward most of the time, but it's there because form widgets CAN add interesting things to the end of the ID's based on whether or not the widget is a radio select for example.
From source comments :
# RadioSelect is represented by multiple <input type="radio"> fields,
# each of which has a distinct ID. The IDs are made distinct by a "_X"
# suffix, where X is the zero-based index of the radio field. Thus,
# the label for a RadioSelect should reference the first one ('_0').
Why does the result have to be returned in json?
Because it's an ajax request and javascript easily eats json.
2- could you go through these lines of code...
extra_args_func = kwargs.pop('callback', lambda request, *args, **kwargs: {})
Either return a keyword argument named 'callback' (which if passed in, is supposed to be a function that accepts request and return a dictionary), and if it wasn't, return a lambda function that only returns an empty dictionary.
I'm not sure what the specific use is for the extra context. You could use it to run arbitrary snippets of code without modifying or subclassing ajax_validation...
It might help you to run this code, and put a debugger breakpoint in somewhere so you can step through and examine the variables and methods. You can do this by simply putting this line where you want to break:
import pdb; pdb.set_trace()
and you will be dumped into the debugger in the console.