I'm using MultiSelectField in my form, which allows the user to select multiple choices:
models.py
physical_limits = MultiSelectField('Physical Limitations', choices=PHYSICAL_LIMIT, max_length=255)
screenshot link
However, I would like to add few additional fields per choice, e.g. min value, max value, units, etc (for the user to fill in, for each choice he makes).
For example, if the user selects option (2), which is "Solid", he will then be able to fill in additional corresponding "sub-fields" for this selection.
In some way, I feel like I'm looking for a different field type, which acts more like a table or array, for the user to fill. I couldn't find such a thing though..
"Vision"
Can you please guide me how to achieve that goal?
Thanks ahead,
Shahar
Related
Been searching the web for a couple hours now looking for a solution but nothing quite fits what I am looking for.
I have one model (simplified):
class SimpleModel(Model):
name = CharField('Name', unique=True)
date = DateField()
amount = FloatField()
I have two dates; date_one and date_two.
I would like a single queryset with a row for each name in the Model, with each row showing:
{'name': name, 'date_one': date_one, 'date_two': date_two, 'amount_one': amount_one, 'amount_two': amount_two, 'change': amount_two - amount_one}
Reason being I would like to be able to find the rank of amount_one, amount_two, and change, using sort or filters on that single queryset.
I know I could create a list of dictionaries from two separate querysets then sort on that and get the ranks from the index values ...
but perhaps nievely I feel like there should be a DB solution using one queryset that would be faster.
union seemed promising but you cannot perform some simple operations like filter after that
I think I could perhaps split name into its own Model and generate queryset with related fields, but I'd prefer not to change the schema at this stage. Also, I only have access to sqlite.
appreciate any help!
Your current model forces you to have ONE name associated with ONE date and ONE amount. Because name is unique=True, you literally cannot have two dates associated with the same name
So if you want to be able to have several dates/amounts associated with a name, there are several ways to proceed
Idea 1: If there will only be 2 dates and 2 amounts, simply add a second date field and a second amount field
Idea 2: If there can be an infinite number of days and amounts, you'll have to change your model to reflect it, by having :
A model for your names
A model for your days and amounts, with a foreign key to your names
Idea 3: You could keep the same model and simply remove the unique constraint, but that's a recipe for mistakes
Based on your choice, you'll then have several ways of querying what you need. It depends on your final model structure. The best way to go would be to create custom model methods that query the 2 dates/amount, format an array and return it
I'm trying to make something like the image below. Let's say that I have 3 multiple choice fields like the following. If I choose bags from choices_first, I want choices_for_bags to show up as the next choice step.
The below image is one of the fields for Django default user model. It's for another purpose. I'm looking for something like that. As I choose something on the left, I want something to show up on the right based on the choice on the left. Does Django admin provide anything like that as default or is there any library for that?
choices_first = (
('clothing', 'Clothing'),
('bags', 'Bags'),
)
choices_for_clothing = (
('tops', 'Tops'),
('bottoms', 'Bottoms'),
)
choices_for_bags = (
('handbags', 'Handbags'),
('backpacks', 'Backpacks'),
)
As far as I know django-smart-selects provide ChainedManyToManyField option which should be similar to User Permissions scenario since its ManyToMany field, but I'm not sure if it will work as you need.
I'm implementing search functionality with an option of looking for a record by matching multiple tables and multiple fields in these tables.
Say I want to find a Customer by his/her first or last name, or by ID of placed Order which is stored in different model than Customer.
The easy scenario which I already implemented is that a user only types single word into search field, I then use Django Q to query Order model using direct field reference or related_query_name reference like:
result = Order.objects.filter(
Q(customer__first_name__icontains=user_input)
|Q(customer__last_name__icontains=user_input)
|Q(order_id__icontains=user_input)
).distinct()
Piece of a cake, no problems at all.
But what if user wants to narrow the search and types multiple words into search field.
Example: user has typed Bruce and got a whole lot of records back as a result of search.
Now he/she wants to be more specific and adds customer's last name to search.So the search becomes Bruce Wayne, after splitting this into separate parts I'm having Bruce and Wayne. Obviously I don't want to search Orders model because order_id is a single-word instance and it's sufficient to find customer at once so for this case I'm dropping it out of query at all.
Now I'm trying to match customer by both first AND last name, I also want to handle the scenario where the order of provided data is random, to properly handle Bruce Wayne and Wayne Bruce, meaning I still have customers full name but the position of first and last name aren't fixed.
And this is the question I'm looking answer for: how to build query that will search multiple fields of model not knowing which of search words belongs to which table.
I'm guessing the solution is trivial and there's for sure an elegant way to create such a dynamic query, but I can't think of a way how.
You can dynamically OR a variable number of Q objects together to achieve your desired search. The approach below makes it trivial to add or remove fields you want to include in the search.
from functools import reduce
from operator import or_
fields = (
'customer__first_name__icontains',
'customer__last_name__icontains',
'order_id__icontains'
)
parts = []
terms = ["Bruce", "Wayne"] # produce this from your search input field
for term in terms:
for field in fields:
parts.append(Q(**{field: term}))
query = reduce(or_, parts)
result = Order.objects.filter(query).distinct()
The use of reduce combines the Q objects by ORing them together. Credit to that part of the answer goes to this answer.
The solution I came up with is rather complex, but it works exactly the way I wanted to handle this problem:
search_keys = user_input.split()
if len(search_keys) > 1:
first_name_set = set()
last_name_set = set()
for key in search_keys:
first_name_set.add(Q(customer__first_name__icontains=key))
last_name_set.add(Q(customer__last_name__icontains=key))
query = reduce(and_, [reduce(or_, first_name_set), reduce(or_, last_name_set)])
else:
search_fields = [
Q(customer__first_name__icontains=user_input),
Q(customer__last_name__icontains=user_input),
Q(order_id__icontains=user_input),
]
query = reduce(or_, search_fields)
result = Order.objects.filter(query).distinct()
I am trying to write a Django app that does the following:
A user sees various articles and then codes variables against these articles.
i.e.:
Article is about Egypt.
User assigns: country = Egypt
This, so far, is easy.
What I would love to have, though, is that the user can create the variables himself, without me having to hard-code them into models.
How do I best do this?
Should I use the through-relationship on a manytomany-field or are there other, better, ways to do this?
If I use the through-relationship, how can I let the user choose what data-type the variable should be?
Should I put a field for every fieldtype into the through-model and then have the user choose it somehow?
I know, this is more than one question, but if you answer my first question I would be very happy!
I am assuming that by "user" you mean other apps that are based on the app that contains Article.
Use model inheritance:
https://docs.djangoproject.com/en/dev/topics/db/models/#model-inheritance
class Article(models.Model):
pub_date = models.DateTimeField(...)
class CountryArticle(Article):
country = SomeSuitableModel()
I need a solution for this problem:
I would like to have MultiField widget for a "value" field. This field should allow to input two values (two input widgets), and user should choose which of these values is to be saved (two checkbox widgets). However, one of these values must be recalculated with respect to other field's value.
I've taken this approach:
a MultiValueField with 4 fields:
class PriceDetailField(MultiValueField):
use_net = BooleanField(required=False)
net_value = DecimalField(required=False, decimal_places=2)
use_gross = BooleanField(required=False)
gross_value = DecimalField(required=False, decimal_places=2)
a MultiWidget:
class PriceDetailWidget(MultiWidget):
use_net = CheckboxInput()
net_value_widget = TextInput()
use_gross = CheckboxInput()
gross_value_widget = TextInput()
and a custom Form...
class PriceModelForm(ModelForm):
value = PriceDetailField()
...which overrides default model form for a model:
class Price(models.Model):
value = models.DecimalField(
max_digits=19,
decimal_places=2,
default=Decimal(0),
)
However, this solution seems to be messed up. In the form, I need to input all subfields (the MultiValueField subfields), otherwise "Please enter value" error appears (even though those fields are marked as required=False). Also,
I must recalculate the mentioned value upon a save, having returned a tuple from the field with information which checkbox was checked and the corresponding text value, then replace the tuple with the decimal value in clean_value method of form (also, saving the checkboxes state in temporary fields....). I think such a design is very weak.
The form should work both on its own and as inline (this means, the value of the field which is used to calculate the returned value can or cannot change during save).
Is such a thing even possible?
And the root of the problem: I want to store prices of items as net prices, but I would like to allow users to input them as net or gross prices, and then recalculate gross price to net price with respect to product's VAT tax level (since VAT is assigned to product or service, not to the price). A product can have many prices, so a price is backlinked to the product by a foreign key.
Cheers,
Tomek
The feature you're looking for on a MultiValueField (allowing the sub-fields to be required or not individually) is logged as a feature request on Django.
You could probably fix this for now by subclassing MultiValueField with a rewritten clean method based on the original and following suggestions from the bug report. You're not going to have a lot of the original MultiValueField left by that point though, and if you do, you should submit your patch to Django and put a note on the bug.
Ignoring for a moment the requiredness thing, have you written a compress method on your PriceDetailField? What does it look like? This is where you should be doing the work to turn your four sub-fields into a single field to save.