I have 2 models linked 'Project' and 'Event'. Event has an FK to Project
I want to return all events that are related only to the project.
I have a basic view that returns the specific project and im trying to include the event list within that view.
def show_project_details(request,project_id):
today = now().date()
project = Project.objects.get(pk=project_id)
events = Event.objects.event_list = Event.objects.filter(event_date__gte=today).order_by('event_date')
events_list = Event.objects.get(project_name_id=project_id)
form = ProjectForm(request.POST or None, instance=project)
return render(request, 'pages/project_details.html', {"project": project, "form": form, "events": events, 'events_list':events_list})
but it returns
Event matching query does not exist.
Any ideas?
to get all the event related to a particular project
use
project = Project.objects.get(pk=project_id)
events = project.event_set.filter(event_date__gte=today).order_by('event_date')
so the full view would reduce to
def show_project_details(request,project_id):
today = now().date()
project = Project.objects.get(pk=project_id)
events = project.event_set.filter(event_date__gte=today).order_by('event_date')
form = ProjectForm(request.POST or None, instance=project)
return render(request, 'pages/project_details.html', {"project": project, "form": form, "events": events})
Brian Obot's answer is a very good solution to your actual problem.
To answer your question why you get this specific error with your code:
Event matching query does not exist.
As you have not (yet) provided your models, I can only guess that the error occurs for this line of code:
events_list = Event.objects.get(project_name_id=project_id)
objects.get will always raise an error if it does not exactly find 1 single object. For fetching data that can return 0 to many results (as is the case for regular reverse foreign key relations), you should use filter.
Your current code should work if you change the above line to:
events_list = Event.objects.filter(project_name_id=project_id)
This really will return a list (actually a queryset) - that could also be empty.
In terms of performance / amounts of statements executed on the database:
Both ways (project.event_set and Event.objects.filter) will result in extra statements to the database.
If you want to avoid that and fetch everything when you fetch the project data, you would have to work with annotations.
As long as you are not experiencing any issues, it's fine to leave it as is. If you are interested to venture into that area, read more: https://docs.djangoproject.com/en/3.2/ref/models/querysets/#annotate
Related
I have a simple(I think) question, about Django context rendering.
I'll step right into it -
Basically what I need is, some temp table, which in my case, I called Locked. And when a user presses a button, which Is a form, that object goes straight to the table Locked(just a simple insert). And inside that table there is a field called is_locked, and if its True, that object needs to go gray, or to have some lock icon inside the html table.
Just some kind of a viewable sign, that an object is inside the table Locked, and that another user can't access it.
But, my problem is, since in my views.py, my lock function is not returning exact html where I want to render that locker icon, instead, it returns another html.
Is there any way, to render same context, on 2 html pages? Thank's.
This is my code :
views.py
def lock(request, pk):
# Linking by pk.
opp = get_object_or_404(OpportunityList, pk=pk)
opp_locked = get_object_or_404(Locked, pk=pk)
# Taking two parametters for 2 fields.
eluid = Elementiur.objects.get(eluid=pk)
user = User.objects.get(username=request.user)
# Dont bother with this one! Just pulling one field value.
field_name = 'optika_korisnik'
obj = OpportunityList.objects.get(pk=pk)
field_object = OpportunityList._meta.get_field(field_name)
field_value = getattr(obj, field_object.attname)
# This is the main part! This is where i'm inserting data into Locked table.
if opp_locked.DoesNotExist:
opp_locked.id = int(eluid.eluid)
opp_locked.locked_eluid = eluid
opp_locked.locked_comment = field_value
opp_locked.locked_user = user
opp_locked.locked_name = 'Zaključao korisnik - ' + request.user.username
opp_locked.is_locked = True
opp_locked.save()
# This is what has to be returned, but i need context on the other page.
return render(request, 'opportunity/detalji/poziv.html',
{'opp': opp, 'locked': opp_locked})
else:
# This return has the context that i need(from the first opp_locked variable)
return render(request, 'opportunity/opp_optika.html', {'locked_test': opp_locked})
I can provide more code, but i think that it's not important for this type of question, because all of the logic is happening inside the lock finction, and last two returns.
I just had a quick overview of your snippet sorry if this not help you but you need to review it a little bit.
You call DoesNotExist on an instance of a Locked model
if opp_locked.DoesNotExist: [...]
that's not how you should use this exception.
You have a method .exists() that is available but only for Querysets.
Also if your instance does not exists you are alredy returning an Http404 response when you use get_object_or_404() method.
And perhaps you should avoid sharing primary keys between instances and replace them with models.OneToOneField (OneToOnefield)
Since i got no answers, i added a new field, is_locked, into my Locked model and that solved it.
So, I have a form that logged in user can fill, and when that form is submitted, I'd like it to generate a temporary link to another form that non-logged in users could access and fill, that would last 24 hours. That form would then send data to the database. That link would be valid only several times. that number is determined in the first form, by the logged in user.
I would like that URL to be as short as possible and easy to write down manually on a browser, but I don't know the best way to do so, or even how to do so.
The first form is completed, and only logged in user can fill it, but I do not know how to generate that temporary link.
Please keep in mind that I am fairly new to Django.
Views.py
class GenFormPageView(LoginRequiredMixin, TemplateView):
login_url = '/'
def get(selfself, request, **kwargs):
if request.method == 'POST':
formation_form = genForm(data=request.POST)
if formation_form.is_valid():
cdata = formation_form.cleaned_data.get
else:
print('Invalid')
else:
formation_form = genForm()
return render(request, 'genform.html', {'formation_form': formation_form})
Forms.py
class genForm(forms.ModelForm):
liste_formation = []
formations_info = {}
for formation in Formation.objects.all():
if formation.libelle in formations_info:
formations_info[formation.libelle].append(formation.formateur, formation.dateDebut, formation.dateFin,
formation.nbJours, formation.cours)
else:
info = {'formateur':formation.formateur.get_full_name(), 'dateDebut':formation.get_debut(), 'dateFin':formation.get_fin(), 'nbJours':formation.nbJours, 'cours':formation.cours.get_titre()}
formations_info[formation.libelle] = info
liste_formation.append(formations_info)
formations = [str(formation) for formation in Formation.objects.all()]
formation_select = forms.ChoiceField(label='Formation', choices=([(formation, formation) for formation in formations]), required = True)
formateur = forms.CharField(label='Formateur')
cours = forms.CharField(label='Cours')
nombre_eleves = forms.IntegerField(label='Nombre d\'élèves', min_value=1)
formations = json.dumps(formations_info)
class Meta:
model = Formation
fields = ('formation_select', 'formateur', 'dateDebut', 'dateFin', 'nbJours', 'cours', 'nombre_eleves')
urls.py
url(r'^genform/$', views.GenFormPageView.as_view()),
Here is the field tht is going to determine the number of time the new form can be submitted
When I click the button 'Generer', it creates a link to a form. that form can only be submitted a fixed number of time, and the link can only lead to that form if clicked within 24 hours from the generated time.
What I am trying right now, is creating a field in my database containing the time when the form is generated, and then I will check if the time is valid, and display the form only if it is.
That my idea right now, but I still don't konw how to do it.
So, to answer my question, I finally decided to use a field in my database containing the date of the creation of the form, then I would just check that today's date is within 24 hours from the date in my database.
I'm trying to implement the FullCalendar on my website, but am a little new to this and not quite sure how to format what I want to do. I have a view which will grab all of an individual user's events. I want to take those events and populate the calendar with them. My issue is that I don't know what to return in the view or how to handle that return value in the JavaScript function. Here's what I have right now:
View:
def calEvents(request):
user = request.user.get_profile()
eventList = user.eventList
ownedList = user.ownedEvent
events = #Part I'm having trouble with
return HttpResponse(events)
The eventList and ownedEvent keep track of all of a user's events. They have names/dates associated with them. What I don't understand is the format I need to put all that information in to return in my HttpResponse.
My JavaScript function is:
$(document).ready(function() {
$('#calendar').fullCalendar({
eventSources: [
{
url: '/calEvents/',
editable: false,
}
]
});
});
I'm telling it to go to the Django view, but am lost after that. Thanks so much in advance!
I have done this by building a list of dictionaries in my Django view, setting at minimum the required fields of 'title' and the start time, then using simplejson.dumps with cls=DjangoJSONEncoder to return json.
from django.core.serializers.json import DjangoJSONEncoder
def calEvents(request):
# as above, then:
events = []
for event in eventList:
events.append({'title': event.name, 'start': event.start})
# something similar for owned events, maybe with a different className if you like
return HttpResponse(simplejson.dumps(events, cls=DjangoJSONEncoder), mimetype='application/json')
You may also with to limit the events you return based on the starting and ending times provided by the get request:
def calEvents(request):
user = request.user.get_profile()
start_timestamp = request.GET.get('start')
end_timestamp = request.GET.get('end')
start_datetime = datetime.datetime.fromtimestamp(float(start_timestamp))
end_datetime = datetime.datetime.fromtimestamp(float(end_timestamp))
eventList = user.eventList.filter(start_time__lte=end_datetime, end_time__gte=start_datetime)
I am neglecting error handling for the timestamp conversion - fullcalendar will give you appropriate values, but it would be best to allow for the possibility of bad input. And I am making assumptions about the structure of your event models.
We are building a wizard using Django 1.4's new form wizard functionality.
The docs on this are very terse and we can't find any advanced examples. We are using a named step wizard (needed to support a listview/datagrid we use) and a session backend.
The wizard is meant to edit roles and linked rights and is built to provide both add and edit functionality. We do this by asking the user in the first step if he/she wants to add or edit.
The next step depends on that choice;
If the user wants to edit, there is a search screen, followed by a listview/datagrid that displays results. The user can then select one of the results and goes to a details-screen, followed by a FilteredSelectMultiple page, allowing him/her to link rights to this role.
If the user wants to add a new role, the search and results screens are skipped and the user goes directly to the details screen, followed by the link-screen.
It all works pretty well, using a condition_dict in urls.py, but we are wondering a couple of things about the general functionality:
When a specific pre-existing role is selected, how can we fill the details and the link-screen with the corresponding data?
Do we instantiate a roles-object and pass it somehow to the two forms, if so, where do we instantiate it and do we need to do that for every form separately (which seems a bit over the top)?
When saving, is it common practice to create another instance of a role object, add the form data to it and save, or can we re-use the object used in the forms somehow?
We have tried overloading get_form_instance to return instances of roles, and we have looked at instance_dict in the docs, but it feels like the wrong approach and there are no examples to be found online, and we're not even sure these are used to pre-fill data or even if we're on the right track.
Logically, I would say in the step that selects an existing role, I need to fill the wizard-variables using an instance of the chosen object, and these get displayed in the forms. At the end of the wizard we reverse the process and get all data from the wizard-variables and add them to a newly instantiated roles-object and save it. Ideally this instance will determine itself if it needs to perform an INSERT or an UPDATE, depending on whether or not the promary key is filled.
If anyone can provide an example, or a nudge in the right direction, it would be very much appreciated.
The code of the wizardview class in views.py is below:
class RolesWizard(NamedUrlSessionWizardView):
def get_template_names(self):
# get template for each step...
if self.steps.current == 'choice':
return 'clubassistant/wizard_neworeditrole.html'
if self.steps.current == 'search':
return 'clubassistant/wizard_searchrole.html'
if self.steps.current == 'results':
return 'clubassistant/wizard_pickrole.html'
if self.steps.current == 'details':
return 'clubassistant/wizard_detailsrole.html'
elif self.steps.current == 'rights':
return 'clubassistant/wizard_roles.html'
def get_context_data(self, form, **kwargs):
# get context data to be passed to the respective templates
context = super(RolesWizard, self).get_context_data(form=form, **kwargs)
# add the listview in the results screen
if self.steps.current == 'results':
# get search text from previous step
cleaned_data = self.get_cleaned_data_for_step('search')
table = RolesTable(Roles.objects.filter(
role_name__contains=cleaned_data['searchrole'])
)
RequestConfig(self.request, paginate={
"per_page": 4,
}).configure(table)
# add the listview with results
context.update({'table': table})
# add a role instance based on the chosen primary key
if self.steps.current == 'rights':
cleaned_data = self.get_cleaned_data_for_step('results')
role_id = cleaned_data['role_uuid']
role = get_object_or_404(Roles, pk=role_id)
context.update({'role': role})
return context
def done(self, form_list, **kwargs):
# this code is executed when the wizard needs to be completed
# combine all forms into a single dictionary
wizard = self.get_all_cleaned_data()
if wizard.get("neworeditrole")=="add":
role = Roles()
else:
role = get_object_or_404(Roles, pk=wizard.get("role_uuid"))
# many-to-many rights/roles
role.role_rights_new_style.clear()
for each_right in wizard.get('role_rights_new_style'):
RightsRoles.objects.create(role=role, right=each_right,)
# other properties
for field, value in self.get_cleaned_data_for_step('details'):
setattr(role, field, value)
role.save()
# return to first page of wizard...
return HttpResponseRedirect('/login/maintenance/roles/wizard/choice/')
For future googlers:
I had some success with using get_form() because it is called before a form is rendered. Start with a couple of ModelForms:
class Wizard1(models.ModelForm):
class Meta:
model = MyModel
fields = ('field0', 'model0')
class Wizard2(models.ModelForm):
class Meta:
model = MyModel
excludes = ('field0', 'model0')
Then, in your SessionWizardView:
class MyWizard(SessionWizardView):
def get_form(self, step=None, data=None, files=None):
form = super(ExtensionCreationWizard, self).get_form(step, data, files)
if step is not None and data is not None:
# get_form is called for validation by get_cleaned_data_for_step()
return form
if step == "0":
# you can set initial values or tweak fields here
elif step == "1":
data = self.get_cleaned_data_for_step('0')
if data is not None:
form.fields['field1'].initial = data.get('field0')
form.fields['field2'].widget.attrs['readonly'] = True
form.fields['field3'].widget.attrs['disabled'] = True
form.fields['model1'].queryset = Model1.objects.filter(name="foo")
return form
The action is all in step 1. You request validated data from step 0 (which triggers another call to get_form() for step 0, so be careful) and then you can access any values that were set in step 0.
I threw in a couple of examples of settings you can change on the fields. You can update a queryset to limit the values in a ChoiceField, or re-display a value again but make it read-only. One caveat I noticed... readonly does not work on ChoiceField. You can make it disabled, but then the value is not propagated when you submit the form.
Let's see if I can help. I did a form wizard that adds steps depending on the answers. At each step I save all forms in a session variable, like so:
def process_step(self, request, form, step):
request.session['form_list'] = self.form_list
request.session['initial'] = self.initial
Then, each time that view is rendered, I instantiate a new form wizard with all the previous data:
def dynamic_wizard(request):
if not request.session.get('form_list'):
form = Wizard([Form1])
else:
form = Wizard(request.session.get('form_list'), initial = request.session['initial'])
return form(context=RequestContext(request), request=request)
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.