Recursive Relationship with a Description in Django Models - python

My project involves sorting many images. As part of this sorting, I want to be able to manually (as the user) mark several images as duplicates of each other with a brief description of why each relationship was created. These relationships will not be defined at the time an image is loaded into Django, but at a later time after uploading all the images.
My question: How can I create an unlimited number of duplicates? Aka, how would I define that several images are all related to each other, and include a CharField description of why each relationship exists?
This is a django app and the code is from models.py.
Thank you.
from django.db import models
class tag(models.Model):
tag = models.CharField(max_length=60)
x = models.IntegerField(null=True)
y = models.IntegerField(null=True)
point = [x,y]
def __unicode__(self):
return self.tag
#...
class image(models.Model):
image = models.ImageField(upload_to='directory/')
title = models.CharField(max_length=60, blank=True, help_text="Descriptive image title")
tags = models.ManyToManyField(tag, blank=True, help_text="Searchable Keywords")
#...
##### HELP NEEDED HERE ##################
duplicates = [models.ManyToManyField('self', null=True), models.CharField(max_length=60)]
##########################################
def __unicode__(self):
return self.image.name

You'd have to go with an extra model for grouping those duplicates, because you want a description field with it. Something like
class DupeSeries(Model):
description = CharField(...)
members = ManyToManyField("image", related_name="dupes", ...)
Example usage:
img = image(title="foo!", image="/path/to/image.jpg")
dup_of_img = image(title="foo!dup", image="/path/to/dup/image.jpg")
img.save()
dup_of_img.save()
dupes_of_foo = DupeSeries(description="foo! lookalikes")
dupes_of_foo.members.add(img, dup_of_img)
# Notice how *img.dupes.all()* returns both image instances.
assert(list(img.dupes.all()) == [img, dup_of_img])

Related

Django, 2 forms on one page, one form uses data from the other

Here are my models:
from django.db import models
ATTACK_TYPES = ('EXA','Example')
class AttackImage(models.Model):
title = models.CharField(max_length=255)
image = models.ImageField(upload_to='attack_images')
source_url = models.URLField(blank=True,null=True)
class AttackItem(models.Model):
attack_image = models.ForeignKey(AttackImage, on_delete=models.CASCADE)
attack_used = models.CharField(max_length=55, choices=ATTACK_TYPES)
hidden_data_found = models.BooleanField(blank=True)
I want a user to be able to create an attackitem and an attackimage at the same time, with the attackitem having a foreignkey relation to the attackimage, as you can see. How can I do this? Thanks in advance.

Insert multiple keywords in one field

My question is how i can insert multiple keywords in one django field and show them in a template like stackoverflow tags.
Models:
class Jobs(models.Model):
title = models.CharField(max_length=100)
slug = models.SlugField(blank=True, default='')
company = models.ForeignKey(Company, on_delete=models.CASCADE)
tags = ?????
Create another class and use many-to-many relationship between jobs class (tags) and new class:
class Tags(models.Model):
tag_name=models.CharField()
In jobs class
tags=models.ManyToManyField(Tags)
For show in template you can use for loop, etc.
Make it a Comma separated value.
class Jobs(models.Model):
tags = models.TextField()
def tag_list(self):
return self.tags.split(",")
def add_tag(self, tag_str):
current_tags = self.tag_list()
current_tags.append(tag_str)
current_tags = set(current_tags)
new_tag_string = ",".join(current_tags)
self.tags = new_tag_string
# you could save the model now or let caller save it outside of this method. I suggest letting caller save the model.
def remove_tag(self, tag_str):
current_tags = self.tag_list()
current_tags.remove(tag_str)
new_tag_string = ",".join(current_tags)
self.tags = new_tag_string
# you could save the model now or let caller save it outside of this method. I suggest letting caller save the model.

Auto Incrementing natural keys with django / postgres

Let me preface this in saying that I'm a UI dev who's trying to branch out into more backend coding, so excuse me if my verbiage is off at all. This is could be a duplicate, but i'm not sure what on god's good green earth i'm even supposed to call what i want to do.
Basically, I have categories, and images. I need to label each image with an acronym of the category it belongs to, and increment a sku after.
For Example, the following images would be automatically labeled like...
ABC-1
ABC-2
DEF-1
DEF-2
DEF-3
ABC-3*
*note: I want it to increment the ID based on the category, not the total # of images
How would I achieve this in idiomatic Django?
Models:
class Group(models.Model):
title = models.CharField(max_length=200)
abbv = models.CharField(max_length=200)
urlified = models.CharField(max_length=200)
description = models.TextField(blank=True)
hidden = models.BooleanField()
def __unicode__(self):
return self.title
class Photo(models.Model):
group = models.ForeignKey(Group)
title = models.CharField(max_length=200)
description = models.TextField(blank=True)
pub_date = models.DateTimeField(auto_now_add = True, blank=True)
image = models.ImageField(max_length=100)
class Meta:
ordering = ('pub_date',)
If you want true composed primary keys, you might want to use django-compositepks, but that is not ideal. You might be better off breaking DRY and recording the number (see the category_auto_key field and default).
Transactions will solve it this way:
from django.db import transaction
class Group(models.model):
# your fields
img_count = models.IntegerField()
#transaction.atomic
def next_sku(self):
self.img_count += 1
self.save()
return self.img_count
class Photo(models.Model):
# your fields
category_auto_key = models.IntegerField(editable=False)
def category_image(self):
return self.group.abbv+"-"+str(self.category_auto_key)
def save(self, *args, **kwargs):
if not self.category_auto_key:
self.category_auto_key = self.group.next_sku()
super(Photo, self).save(*args, **kwargs)
When you need this in your templates, just enclose it in double brackets:
{{ photo.category_image }}
I'm curious if you just want to generate and store the acronym and sku in a text field, or if you are trying to create relationships between your image categories?
If the later, I would look for a different approach.
If the former, i would use a customized set or save method (hook?) for your image model. It will need do a small one time lookup to count the number of acronym already existing, but I wouldn't worry about the performance too much.
Wasn't sure how to do this exactly in Django off the top of my head, but it looks like the accepted answer works similarly. Anyways, here is my attempt at setting a Model Field during save. Be warned this in untested.
After looking into it more I think that Beltiras' solution is better
class Photo(models.Model):
# simple column definitions
group = models.ForeignKey(Group)
title = models.CharField(max_length=200)
description = models.TextField(blank=True)
pub_date = models.DateTimeField(auto_now_add = True, blank=True)
image = models.ImageField(max_length=100)
# new column for storing abbv sku
category_label = models.CharField(max_length=200)
# save override
def save(self, *args, **kwargs):
# hopefully only set category_label on first save, not sure this
# works, open to other ideas
if (self.pk is None):
count = Photo.objects.filter(group=self.group).count()
label = self.group.abbv + '-' + count
setattr(self, 'category_label', label)
# call the super class' save method
super(Photo, self).save(*args, ** kwargs)
The part I am least sure about is:
count = Photo.objects.filter(group=self.group).count()
The idea is to query the photos table for photos in the same group and count them. This may need to be replaced with a direct SQL call or done some other way. Let me know what you find.

Django rest framework saving thumbnail image

I've recently started developing with django + python and everything was going very smooth until I got stuck into a problem that probably is very simple but I can not solve with my inexperience with the framework/language.
I'm receiving an JSON object through an HTTP Request which contains some data and 2 pictures. Prior to those 2 pictures I wanted to save a thumbnail from one of them but I don't see to get that task done. I can save all the data easily including the 2 images. But I can not see to find a way to generate a way an have that in the DB also, as well the folder structure that I want.
My folders should look like:
pictures
user
originals
processed
thumbnails
otherUser
originals
processed
thumbnails
My goal is: Receive 2 pictures, create a thumbnail from one of them and them save all 3 pictures in 3 separate folders and the path to the Database.
Here's how my model code looks like.
class SomeData(models.Model):
owner = models.ForeignKey('auth.User', related_name='canopeo_data')
adjustments = models.CharField(max_length=10)
latitude = GeopositionField()
longitude = GeopositionField()
notes = models.TextField(null=True, blank=True)
original_image = models.ImageField(upload_to=original_image, max_length=255, blank=True)
processed_image = models.ImageField(null=False, upload_to=processed_image, max_length=255)
thumbnail_image = models.ImageField(null=False, upload_to=thumbnail_image, max_length=255)
date_time = models.DateTimeField(auto_now_add=True)
class Meta:
ordering = ('date_time',)
def save(self, *args, **kwargs):
super(SomeData, self).save(*args, **kwargs)
def original_image(self, filename):
url = "pictures/%s/originals/%s" % (self.owner.username, filename)
return url
def processed_image(self, filename):
url = "pictures/%s/processed/%s" % (self.owner.username, filename)
return url
def thumbnail_image(self, filename):
url = "pictures/%s/thumbnail/%s" % (self.owner.username, filename)
return url
Serializer code...
class SomeDataSerializer(serializers.HyperlinkedModelSerializer):
#url = serializers.HyperlinkedRelatedField(view_name='data', format='html')
owner = serializers.Field(source='owner.username')
thumbnail_image = serializers.Field(source='original_image')
class Meta:
model = SomeData
fields = ('url', 'adjustments', 'latitude', 'longitude', 'notes', 'original_image', 'processed_image',)
View code...
class SomeDataViewSet(viewsets.ModelViewSet):
queryset = SomeData.objects.all()
serializer_class = SomeDataSerializer
permission_classes = (permissions.IsAuthenticatedOrReadOnly,)
def pre_save(self, obj):
obj.owner = self.request.user
I've tried many things such as easy_thumbnails, sorl_thumbnail, and some pre made methods on how to do it.. but I can't see to find a solution specific for what I've been wanting.
Thank you very much!
Looks like you have mistake in definition of the SomeDataSerializer. In model SomeData field original_image defined as ImageField, but in serialiser it's just Field, not ImageField. You should use correct field type:
class SomeDataSerializer(serializers.HyperlinkedModelSerializer):
#url = serializers.HyperlinkedRelatedField(view_name='data', format='html')
owner = serializers.Field(source='owner.username')
thumbnail_image = serializers.ImageField(source='original_image')
...

Django one-to-many relations in a template

I am searching of a method to obtain html forms from some one-to-many relations, like order-lineorder, invoice-lineinvoice, etc.
Let me an example:
# models.py
class Order(models.Model):
date = models.DateTimeField()
number = models.IntegerField(default=0)
class LineOrder(models.Model):
description = models.TextField()
price = models.FloatField()
order = models.ForeignKey(Order)
# views.py
def order_form(request):
form = OrderForm()
table_lineorder = LineOrderTable([])
RequestConfig(request).configure(table)
return render(request, "order_form.html", {"form": form, "table": table_lineorder})
Then, I want to obtain the order template with "generic attributes" (date, number), and a table list (originally empty) of lines order. Add some action like add, edit and remove must be possible.
I think that a solution like django-tables2 is possible, but I can't add rows dinamically, I think.
Thanks in advice.
[EDIT]
I have found the solution. It is django-dynamic-formset
I'm not quite clear about your question, but I guess this might be what you want:
class Order(models.Model):
date = models.DateTimeField()
number = models.IntegerField(default=0)
items = model.ManyToManyField(Item)
class Item(models.Model):
description = models.TextField()
price = models.FloatField()
It should be equivalent to one-to-many if you don't assign one Item to multiple Orders.

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