以Django选择的形式在``模型选择''字段中列出各种模型属性

Question

Models.py

from django.db import models

class Sample(models.Model):
    sample_ID = models.CharField(max_length=20)
    sample_name = models.CharField(max_length=30)


    def __unicode__(self):
        return self.sample_ID

    class Meta:
        ordering = ['id']

Forms.py

from django import forms
from chosen import forms as chosenforms
from .models import Sample

class SampleLookupForm(forms.Form):
    Sample_ID = chosenforms.ChosenModelChoiceField(queryset=Sample.objects.all())

class SampleNameLookupForm(forms.Form):
    def __init__(self):
        samples = Sample.objects.all().values_list('sample_name', flat=True)
        sample_tuple = [(i, i) for i in samples]
        self.fields['Sample_Name'] = chosenforms.ChosenChoiceField(sample_tuple)

Here I have two forms, one of which I would like to show all sample IDs in the drop down menu. The other I would like to show all of the sample names.

For the Sample IDs, this is easy because I have defined the unicode method to return the sample ID. However, I have no clue how to adjust the model, form, or view to create a drop down menu that contains the sample names (ie a model attribute other than that returned in the unicode method.)

How do I allow for model choice fields to display model attributes other than that defined in the unicode method?

Or, should I define the unicode method such that depending on certain conditions it returns a certain model attribute.

I should mention, here I am using django chosen forms which behaves very similarly to Django model forms, just with some added functionality.

The specific error message I am getting with the following code is:

__init__() takes exactly 1 argument (2 given)

Answer 1

I'm not sure about your ChosenModelChoiceField , I'm assuming it's a subclass of ModelChoiceField , you should overwrite label_from_instance method on the field:

class BlahChoiceField(chosenforms.ChosenModelChoiceField):
    def label_from_instance(self, obj):
        # return whatever text you want
        return obj.sample_name

Then for the definition you do:

sample_id = BlahChoiceField(queryset=Sample.objects.all())

django doc .

Edit :

Your original code is on the right path, but your code is wrong on this line:

self.fields['Sample_Name'] = chosenforms.ChosenChoiceField(sample_tuple)

It should be:

self.fields['Sample_Name'] = chosenforms.ChosenChoiceField(choices=sample_tuple)

Answer 2

You could do something like this.

In your model "Sample" define some methods:

@staticmethod
def name_choices():
    return [s.name_choice() for s in Sample.objects.all()]

def name_choice(self):
    return self.sample_name, self.sample_name

And then your form would be:

class SampleNameLookupForm(forms.Form):
    sample_name =  chosenforms.ChosenChoiceField(choices=Sample.name_choices())