---------------- EDIT --------------------
I could not succed doing it with Custom Model Field and I had to move on, so actually, I did it the alternative way specified at the end of this post.
Here is a link to a new post exposing the solution.
---------------- END EDIT --------------------
My app displays formsets where users can create objects. Once validated, the formset is displayed again and user can add new objects.
Dates should only be month and year ("%m/%Y").
I could work on the input field (though jquery) to add '01/' in front of the date entered. But after submitting, the field now displays "%d/%m/%Y" (normal).
So, I'm looking for a way to translate input string (ex : 09/2018) to dateField to store in the database, and then a translate this dateField to string when datas are retrieved from database.
I know, I could simply use a form charfield for months and another one for years.
But I would like to keep it as a date object, so, in templates, I could perform date formatting ({{ edu.start_date |date:"D, d M, Y" }})
Django custom model fields sound made for this : Django custom model fields.
I could do something like this in the custom field:
def string_to_date(value):
value = '01/' + value
la_date = datetime.strptime(value, "%d/%m/%Y").date()
return la_date
def date_to_string(la_date_date):
la_date_str = la_date_date.strftime('%m/%Y')
return la_date_str
class DateYearMonth(models.DateField):
def get_prep_value(self, value):
if value is None:
return value
return string_to_date(value)
def to_python(self, value):
if value is None:
return value
return date_to_string(value)
The form associated (i commented widgets):
class EducationForm(forms.ModelForm):
start_date = forms.CharField()
end_date = forms.CharField()
class Meta:
model = Education
exclude = ("curriculum",)
# # les widgets :
# widgets = {
# 'start_date': forms.TextInput(),
# 'end_date': forms.TextInput(),
# }
Well, this does not work so far. But I don't even know if I'm heading to the right direction...
EDIT
Actually, maybe I could use simple charfield for month and year and add a model method that would create a date out of it (maybe a #property)... This way, I would keep it simple on the form and be able to format on the templates...
You can make the Year an IntegerField and Month (CharField or Integer) and store Year in Months individually is probably the best solution.
Below is an example fore Year only(kind of DatetimeField to YearField)
import datetime
YEAR_CHOICES = []
for r in range(1980, (datetime.datetime.now().year+1)):
YEAR_CHOICES.append((r,r))
year = models.IntegerField(_('year'), choices=YEAR_CHOICES,
default=datetime.datetime.now().year)
Related
I have a programme where users should be able to filter different types of technologies by their attributes. My question is, how would I filter the technologies when there's potential conflicts and empty values in the parameters I use to filter?
Forms.py:
class FilterDataForm(forms.ModelForm):
ASSESSMENT = (('', ''),('Yes', 'Yes'),('No', 'No'),)
q01_suitability_for_task_x = forms.ChoiceField(label='Is the technology suitable for x?',
choices=ASSESSMENT, help_text='Please select yes or no', required=False,)
q02_suitability_for_environment_y = forms.ChoiceField(label='Is the technology suitable for environment Y?',
choices=ASSESSMENT, help_text='Please select yes or no', required=False)
There are many fields in my model like the ones above.
views.py
class TechListView(ListView):
model = MiningTech
def get_queryset(self):
q1 = self.request.GET.get('q01_suitability_for_task_x', '')
q2 = self.request.GET.get('q02_suitability_for_environment_y', '')
object_list = MiningTech.objects.filter(q01_suitability_for_task_x=q1).filter(
q02_suitability_for_environment_y=q2)
return object_list
The difficulty is that not all technology db entries will have data. So in my current setup there's times where I will filter out objects that have one attribute but not another.
For instance if my db has:
pk1: q01_suitability_for_task_x=Yes; q02_suitability_for_environment_y=Yes;
pk2: q01_suitability_for_task_x=Yes; q02_suitability_for_environment_y='';
In the form, if I don't select any value for q01_suitability_for_task_x, and select Yes for q02_suitability_for_environment_y, I get nothing back in the queryset because there are no q01_suitability_for_task_x empty fields.
Any help would be appreciated. I'm also ok with restructuring everything if need be.
The problem is that your self.request.GET.get(...) code defaults to an empty string if there is no value found, so your model .filter() is looking for matches where the string is ''.
I would restructure the first part of get_queryset() to build a dictionary that can be unpacked into your filter. If the value doesn't exist then it doesn't get added to the filter dictionary:
filters = {}
q1 = self.request.GET.get('q01_suitability_for_task_x', None)
q2 = self.request.GET.get('q02_suitability_for_environment_y', None)
if q1 is not None:
filters['q01_suitability_for_task_x'] = q1
... etc ...
object_list = MiningTech.objects.filter(**filters)
If you have a lot of q1, q2, etc. items then consider putting them in a list, looping through and inserting into the dictionary if .get(...) returns anything.
Edit: Because there are indeed a lot possible filters, the final solution looks as follows:
def get_queryset(self):
filters = {}
for key, value in self.request.GET.items():
if value != '':
filters[key] = value
object_list = Tech.objects.filter(**filters)
I am a novice, apologies if this question seems silly. I need to save some data into MySQL database. There are no input fields. The user should click a button, and a table is updated. The data to be saved is two foreign keys and a PK.
Here is my model
class Bids(models.Model):
id=models.AutoField(primary_key=True)
userid = models.ForeignKey(Writer, on_delete=models.DO_NOTHING, related_name='userid ')
orderid = models.ForeignKey(Orders, on_delete=models.DO_NOTHING, related_name='orderids')
biddatetime=models.DateTimeField(auto_now_add=True)
I have tried writing several functions to save these fields into table bids but no joy so far. Hers's a sample.
def saveBid(request):
if request.method!= "POST":
return HttpResponse("Action Not Allowed")
else:
biddatetime=request.POST.get('biddatetime')
bids= Bids(biddatetime=biddatetime)
order=Orders(id=id)
user= CustomUser()
user.save()
bids.save()
Pls assist
I would try sending a POST request to saveBid using Postman and what error you're getting. Post the response from postman here for more help.
It could be that
biddatetime is a string and not a datetime.
On row order=Orders(id=id) you have no variable named id in your code, this will raise error.
In your model Bids the fields userid and orderid do not allow null and blank.
You can use strptime() to convert biddatetime to datetime object.
Try something like that:
from datetime import datetime
def saveBid(request):
if request.method != "POST":
return HttpResponse("Action Not Allowed")
else:
query = request.POST
# See Format Codes - link below
biddatetime = datetime.strptime(query.get('biddatetime'), "%Y-%m-%d")
# get Order
order = Orders.objects.get(id=query.get("order_id")
# create CustomUser
user = CustomUser.objects.create(username="username")
# create Bids
bids = Bids.objects.create(biddatetime=biddatetime, userid=user, orderid=order)
create() method:
create(**kwargs)
A convenience method for creating an object and saving it all in one
step. Thus:
p = Person.objects.create(first_name="Bruce", last_name="Springsteen")
Linkt to Format Codes.
See also Creating objects.
Any reason why you are not using django Form or ModelForm?
class BidForm(forms.Form):
biddatetime = forms.DateTimeField()
.... // other fields
#require_POST
def saveBid(request):
form = BidForm(request.POST)
if form.is_valid():
biddatetime = form.cleaned_data.get('biddatetime')
... // do same for similar fields.
...// after user save
user.refresh_from_db() // post insert you will get the id value for the row
bids = Bids(
biddatetime=biddatetime,
userid=user.userid,
orderid=order.orderids)
bids.save()
I am assuming you are using the id value for user after save if thats not the case you can ignore it.
I post this because I could not find an answer/example that satisfied me and I solved it a way I haven't read in there. Maybe it can be useful or can be discussed.
Basically, my app displays formsets where users can create objects. Once validated, the formset is displayed again and user can add new objects.
Specifying a day is not relevant.
I first started to use some javascript to do it, then played with Django custom model (to subclass models.DateField).
I could not succeed to do it with the later (my post updated linked to this one)
As I have deadlines, I did it with simple ChoiceField storing objects as Integers and then, use a #property method to build a proper date out of those user inputs (add 1 as day).
This way I avoided to deep dive in Django steam pipes and even got rid of a datepicker!
But thanks to the #property, I can still keep the convenience of formatting dates in Django templates and make date calculation etc...
models.py :
NOTE : make use to return None if the date cannot be built out of filled fields, otherwise you'll have an unbound error when trying to render those #property field in a template.
class MyModel(models.Model):
YEAR_CHOICES = [(y,y) for y in range(1968, datetime.date.today().year+1)]
MONTH_CHOICE = [(m,m) for m in range(1,13)]
start_year = models.IntegerField(choices=YEAR_CHOICES,
default=datetime.datetime.now().year,)
start_month = models.IntegerField(choices=MONTH_CHOICE,
default=datetime.datetime.now().month,)
end_year = models.IntegerField(choices=YEAR_CHOICES,
default=datetime.datetime.now().year,)
end_month = models.IntegerField(choices=MONTH_CHOICE,
default=datetime.datetime.now().month,)
#property
def start_date(self):
if self.start_year and self.start_month:
return datetime.date(self.start_year, self.start_month, 1)
elif self.start_year:
return datetime.date(self.start_year, 12, 31)
else:
return None
#property
def end_date(self):
if self.end_year and self.end_month:
return datetime.date(self.end_year, self.end_month, 1)
elif self.end_year:
return datetime.date(self.end_year, 12, 31)
else:
return None
forms.py
class MyModelForm(forms.ModelForm):
class Meta:
model = MyModel
exclude = ("blabla",)
Now, if you want to display a date in a form template, you can use :
{{ form.instance.start_date }}
Hope it helps & Suggestions are welcome!
it was not too clear for me, what are you doing exactly?
if you want to show a date string which has only years and month. that would be achieved by using template-filter date and a format e.g: {{ obj.created_at|date:'%y %m' }}.
but if I'm wrong and may you want to have a custom filed in your modelForm to pick a date(which only has year and month) then something like you've already did is the idea, but the code is the matter
I think your start_date and end_date function need to be changed:
def start_date(self):
if self.start_year and self.start_month:
return datetime.date(self.start_year, self.start_month, 1)
elif self.start_year:
# return Jan 1st
return datetime.date(self.start_year, 1, 1)
else:
return None
def end_date(self):
if self.end_year and self.end_month:
if self.end_month == 12:
# if month is December, return December 31st
return datetime.date(self.end_year, self.end_month, 31)
else:
# else, get first day of next month and subtract 1 day.
return datetime.date(self.end_year, self.end_month+1, 1) - datetime.timedelta(days=1)
elif self.end_year:
return datetime.date(self.end_year, 12, 31)
else:
return None
I'm currently working with django project. I had to filter the data store on the database based on the user input on form (at template) as looked below.
On form user either enter value or leave it blank. So what I have to do is first find the (valid) user input and then fire appropriate query to display data as user input in the form. So final result should be displayed on table at template.
As I'm new to django, how should I have to pass the data and fire query to represent data at multiple field. As help or link related to these type problem are expected. ( I just able to filter from the database with only one form and had no concept to solve this.)
Model of my temp project is as below.
class exReporter(models.Model):
first_name = models.CharField(max_length=30)
last_name = models.CharField(max_length=30)
email = models.EmailField()
gender = models.CharField(max_length=1)
age = models.IntegerField()
label = models.IntegerField()
There are a number of approaches you can take, but here is one solution you can use that involves chaining together the appropriate filters based on the form's posted data:
*Note: To conform to Python's naming convention, rename exReporter class to ExReporter.
# views.py
def process_ex_reporter_form(request):
if request.method == "POST":
# ExReporterForm implementation details not included.
ex_reporter_form = ExReporterForm(request.POST)
if ex_reporter_form.is_valid():
# If form field has no data, cleaned data should be None.
gender = ex_reporter_form.cleaned_data['gender']
age_start = ex_reporter_form.cleaned_data['age_start']
age_end = ex_reporter_form.cleaned_data['age_end']
aggregation_group = ex_reporter_form.cleaned_data['aggregation_group']
aggregation_id = ex_reporter_form.cleaned_data['aggregation_id']
ex_reporters = ExReporter.objects.get_ex_reporters(gender, age_start,
age_end, aggregation_group, aggregation_id)
else:
# Pass back form for correction.
pass
else:
# Pass new form to user.
pass
# models.py
class ExReporterManager(models.Manager):
def get_ex_reporters(self, gender, age_start, age_end, aggregation_group,
aggregation_id):
ex_reporters = super(ExReporterManager, self).get_query_set().all()
# Even though the filters are being applied in separate statements,
# database will only be hit once.
if ex_reporters:
if gender:
ex_reporters = ex_reporters.filter(gender=gender)
if age_start:
ex_reporters = ex_reporters.filter(age__gt=age_start)
if age_end:
ex_reporters = ex_reporters.filter(age__lt=age_end)
# Apply further filter logic for aggregation types supported.
return ex_reporters
I have a couple of simple objects that have a many-to-many relationship. Django has joined them using obj1_obj2 table and it looks like this in mysql;
id | person_id | nationality_id
-----------------------------------
1 | 1 | 1
2 | 1 | 2
Now when I save obj1 (which shows obj2 in as Multi-select in its form) the ids in the obj1_obj2 table increase even thow I have not changed them. For example I change a basic character field for obj1 on its form and save it and the the data in the joining table appears to be deleted and re-saved giving the entries new ids.
In fact I don't have to change anything all I have to do is save the form and the same thing happens.
All I am doing in the view is form.save(), nothing special. Is that the normal way that it works?
EDIT: Added Models, Views, Forms
class Person(models.Model):
name = models.CharField()
birthdate = models.CharField()
nationality = models.ManyToMany(Nationality)
class Employee(Person):
employeeNum = models.CharField()
class FamilyMember(Person):
employee = models.ForeignKey(Employee)
relationship = models.CharField()
class Nationality(models.Model):
abbrev = models.CharField()
country = models.CharField()
class FamilyMemberDetailsForm(forms.ModelForm):
class Meta:
model = FamilyMemeber
exclude = ['employee']
def editFamilyMember(request, familyMember_id):
familyMember = get_object_404(FamilMember, familyMember_id)
if request.method == 'POST':
form = FamilyMemberDetailsForm(request.POST, instance=familyMember)
if form.is_valid():
form.save()
else:
form = FamilyMemberDetailsForm(instance=familyMember)
return render_to_response(editForm.html, {'form':form},
context_instance(RequestContext(request))
This is a cut down version of the models, but the same thing happens for saving an employee or familyMember. The FamilyMember I have shown because it is as simple as this I create the modelForm and then make changes and then save it. For the employee I do some more manipulation in the init of Form for the Nationality, mainly for presentation, and at first I thought it was this manipulation that was causing it, but as I said the same thing happens with the FamilyMember where I do nothing except save.
The Nationality is presented on the form as a multiselect box with a list and the user can select 1 or more from the list. If I just present the populated form and then save it without changing anything the id for the many-to-many table entry changes.
I have changed the example table titles also.
Thanks,
Andrew
Yes, the deletion of any existing rows in appname_obj1_obj2 is expected behavior when saving a form for an object that has a ManyToManyField.
You can see the clear() before the add(**values) in ReverseManyRelatedObjectsDescriptor and ManyRelatedObjectsDescriptor in django/db/models/fields/related.py.
Pop open a shell and take a look at the queries yourself. Something like this should show you the DELETE before the INSERT in the raw sql.
from django.db import connection
fm = FamilyMember.objects.get(pk=1)
form = FamilyMemberDetailsForm(instance=fm)
data = form.initial
data['name'] = "z%s" % data['name']
form = FamilyMemberDetailsForm(data, instance=fm)
connection.queries = [] # clearing to limit the queries you have to look at
form.save()
for q in connection.queries:
print("%s\n" % q['sql'])