{"id":393506,"date":"2024-06-29T11:02:56","date_gmt":"2024-06-29T11:02:56","guid":{"rendered":"http:\/\/savepearlharbor.com\/?p=393506"},"modified":"-0001-11-30T00:00:00","modified_gmt":"-0001-11-29T21:00:00","slug":"","status":"publish","type":"post","link":"https:\/\/savepearlharbor.com\/?p=393506","title":{"rendered":"Django admin dynamic Inline positioning<\/span>"},"content":{"rendered":"
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\"Django
Django ModelAdmin and Inlines<\/figcaption><\/figure>\n

Recently I’ve received an interesting request from a client about one of our Django projects.
He asked if it would be possible to show an inline component above other fields in the Django admin panel.<\/p>\n

At the beginning I thought, that there shouldn’t be any issue with that.
Though there was no easy solution other then installing another battery to the project. My gut feeling told me, there were another way around that problem.<\/p>\n

The first\u00a0solution<\/u><\/a>\u00a0I found was from 2017. It had too much code for such a simple task.<\/p>\n

Our executive lead programmer, Maxim Danilov found quite a short solution. He\u00a0published his work online in russian<\/u><\/a>\u00a0about a month ago.<\/p>\n

I\u00b4d like to share these ideas with englisch speaking Django community in order to help others simplify their code. It might come handy for such a «simple» at first glance issues.<\/p>\n

Long story short, let’s dive into the code:<\/p>\n

Imagine you are building an E-commerce project. You have a\u00a0ProductModel<\/code>which have O2M relation to\u00a0ImageModel<\/code>.<\/p>\n

from django.db import models from django.utils.translation import gettext_lazy as _  class Product(models.Model):   title = models.CharField(verbose_name=_('Title of product'), max_length=255)   price = models.DecimalField(verbose_name=_('Price of product'), max_digits=6, decimal_places=2)  class Image(models.Model):   src = models.ImageField(verbose_name=_('Imagefile'))   product = models.ForeignKey(Product, verbose_name=_('Link to product'), on_delete=models.CASCADE)<\/code><\/pre>\n
You also need\u00a0ModelAdmins<\/code>\u00a0for given models.<\/p>\n
from django.contrib import admin from .models import Image, Product  @admin.register(Product) class ProductModelAdmin(admin.ModelAdmin):   fields = ('title', 'price')  @admin.register(Image) class ImageModelAdmin(admin.ModelAdmin):   fields = ('src', 'product')<\/code><\/pre>\n
Now let’s create a simple inline to put into our\u00a0ProductModelAdmin<\/code>.<\/p>\n
 from django.contrib import admin     from django.contrib.admin.options import TabularInline     from .models import Image, Product      class ImageAdminInline(TabularInline):         extra = 1         model = Image      @admin.register(Product)     class ProductModelAdmin(admin.ModelAdmin):         inlines = (ImageAdminInline,)         fields = ('title', 'price')      @admin.register(Image)     class ImageModelAdmin(admin.ModelAdmin):         fields = ('src', 'product')<\/code><\/pre>\n
So far we have two simple models and basic\u00a0ModelAdmins<\/code>\u00a0with an\u00a0InlineModel<\/code>.<\/p>\n
\"Standard
Standard ModelAdmin With Inline<\/figcaption><\/figure>\n
How should we squeeze that Inline above or in between the two fields of the\u00a0ProductModelAdmin<\/code>?<\/p>\n
I suppose, you are familiar with the\u00a0added field<\/u><\/a>\u00a0concept in\u00a0ModelAdminForm<\/code>. You can create a method in the\u00a0ModelAdmin<\/code>\u00a0to display the response of the method in the form as a readonly field.
Keep in mind, that the rendering sequence of the\u00a0ModelAdmin<\/code>\u00a0will create the\u00a0InlineModels<\/code>\u00a0first, then render\u00a0AdminForm<\/code>\u00a0and after that render the\u00a0InlineForms<\/code>.<\/p>\n
We can use that to rearrange the order of Inlines and fields.<\/p>\n
from django.contrib import admin from django.contrib.admin.options import TabularInline from django.template.loader import get_template from .models import Image, Product  class ImageAdminInline(TabularInline):  extra = 1  model = Image  @admin.register(Product) class ProductModelAdmin(admin.ModelAdmin):   inlines = (ImageAdminInline,)   fields = ('image_inline', 'title', 'price')   readonly_fields= ('image_inline',) # method as readonly field    def image_inline(self, *args, **kwargs):     context = getattr(self.response, 'context_data', None) or {}     inline = context['inline_admin_formset'] = context['inline_admin_formsets'].pop(0)     return get_template(inline.opts.template).render(context, self.request)    def render_change_form(self, request, *args, **kwargs):     self.request = request     self.response = super().render_change_form(request, *args, **kwargs)     return self.response<\/code><\/pre>\n
We use the\u00a0render_change_form<\/code>\u00a0to get the objects\u00a0request<\/code>\u00a0and\u00a0response<\/code>.
We use those objects in the\u00a0image_inline<\/code>\u00a0method to take one\u00a0inline_formset<\/code>\u00a0from the list of\u00a0inline_admin_formsets<\/code>\u00a0that have not been processed yet, and render\u00a0InlineFormset<\/code>.<\/p>\n
After the\u00a0change_form<\/code>\u00a0rendering the remaining\u00a0inline_admin_formsets<\/code>\u00a0will be rendered, in case if the\u00a0ModelAdmin<\/code>\u00a0still has some.<\/p>\n
Now we can use the method\u00a0image_inline<\/code>\u00a0to determine the position of our\u00a0InlineFormset<\/code>.
With the code-snippet above the inline element will be placed above all other fields.<\/p>\n
\"ModelAdminForm
ModelAdminForm with Inline on the top<\/figcaption><\/figure>\n
When we rearrange the fields this way the inline is rendered between the fields:<\/p>\n
@admin.register(Product) class ProductModelAdmin(admin.ModelAdmin):   inlines = ImageAdminInline,   fields = 'title','image_inline', 'price'   readonly_fields= 'image_inline',  # method as readonly field<\/code><\/pre>\n
Of course Django admin adds a lable infront of the Inline with the name of the method, but that can be easily removed by some simple CSS in\u00a0Media<\/code>\u00a0attribute of\u00a0ProductModelAdmin<\/code>.<\/p>\n
\"ModelAdminForm
ModelAdminForm has inline in the middle<\/figcaption><\/figure>\n
This solution has one fatal error! Every Django ModelAdmin is singelton, that is why we can not use ModelAdmin.self as a container in\u00a0<\/strong>render_change_form<\/code>!<\/p>\n
It is possible to change the ModelAdmins singleton\u00b4s behavior with a Mixin, staying inline with the concept of Djangos GCBV. We will take a closer look at it in my next article.<\/p>\n
It simply means, that we can’t use the instance of the\u00a0ModelAdmin<\/code>\u00a0as a container to save our\u00a0request<\/code>\u00a0and\u00a0response<\/code>.
The solution is to save those objects in the\u00a0AdminForm<\/code>\u00a0instance.<\/p>\n
@admin.register(Product)     class ProductModelAdmin(admin.ModelAdmin):         inlines = (ImageAdminInline,)         fields = ('title', 'image_inline', 'price')         readonly_fields= ('image_inline',)  # we set the method as readonly field          def image_inline(self, obj=None, *args, **kwargs):             context = obj.response['context_data']             inline = context['inline_admin_formset'] = context['inline_admin_formsets'].pop(0)             return get_template(inline.opts.template).render(context, obj.request)          def render_change_form(self, request, context, *args, **kwargs):             instance = context['adminform'].form.instance  # get the model instance from modelform             instance.request = request             instance.response = super().render_change_form(request, context, *args, **kwargs)             return instance.response<\/code><\/pre>\n
The argument\u00a0obj<\/code>\u00a0is not always given in\u00a0render_change_form<\/code>\u00a0(i.e. add new object). That is why we have to get it from the\u00a0ModelForm<\/code>, which is wrapped into the\u00a0AdminForm<\/code>.<\/p>\n
Now we can set our request and response as attributes of the\u00a0ModelForm<\/code>\u00a0instance and use those in\u00a0image_inline<\/code>.<\/p>\n
Summing up the above: you don’t have to install another battery to your project to solve a simple problem. Sometimes you need to dig deep enough into the framework that you use, and find a simple, short and quick solution.<\/h4>\n\n
I\u00b4d like to thank Martin Achenrainer the intern of wPsoft for contributing to this article and translating it.<\/p>\n<\/div>\n<\/div>\n<\/div>\n
<\/div>\n

 \u0441\u0441\u044b\u043b\u043a\u0430 \u043d\u0430 \u043e\u0440\u0438\u0433\u0438\u043d\u0430\u043b \u0441\u0442\u0430\u0442\u044c\u0438  https:\/\/habr.com\/ru\/articles\/659173\/<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"
<\/div>\n
\n
\n
\n
\n
Django ModelAdmin and Inlines<\/figcaption><\/figure>\n
Recently I’ve received an interesting request from a client about one of our Django projects.
He asked if it would be possible to show an inline component above other fields in the Django admin panel.<\/p>\n
At the beginning I thought, that there shouldn’t be any issue with that.
Though there was no easy solution other then installing another battery to the project. My gut feeling told me, there were another way around that problem.<\/p>\n
The first\u00a0solution<\/u><\/a>\u00a0I found was from 2017. It had too much code for such a simple task.<\/p>\n
Our executive lead programmer, Maxim Danilov found quite a short solution. He\u00a0published his work online in russian<\/u><\/a>\u00a0about a month ago.<\/p>\n
I\u00b4d like to share these ideas with englisch speaking Django community in order to help others simplify their code. It might come handy for such a «simple» at first glance issues.<\/p>\n
Long story short, let’s dive into the code:<\/p>\n
Imagine you are building an E-commerce project. You have a\u00a0ProductModel<\/code>which have O2M relation to\u00a0ImageModel<\/code>.<\/p>\n
from django.db import models from django.utils.translation import gettext_lazy as _  class Product(models.Model):   title = models.CharField(verbose_name=_('Title of product'), max_length=255)   price = models.DecimalField(verbose_name=_('Price of product'), max_digits=6, decimal_places=2)  class Image(models.Model):   src = models.ImageField(verbose_name=_('Imagefile'))   product = models.ForeignKey(Product, verbose_name=_('Link to product'), on_delete=models.CASCADE)<\/code><\/pre>\n
You also need\u00a0ModelAdmins<\/code>\u00a0for given models.<\/p>\n
from django.contrib import admin from .models import Image, Product  @admin.register(Product) class ProductModelAdmin(admin.ModelAdmin):   fields = ('title', 'price')  @admin.register(Image) class ImageModelAdmin(admin.ModelAdmin):   fields = ('src', 'product')<\/code><\/pre>\n
Now let’s create a simple inline to put into our\u00a0ProductModelAdmin<\/code>.<\/p>\n
 from django.contrib import admin     from django.contrib.admin.options import TabularInline     from .models import Image, Product      class ImageAdminInline(TabularInline):         extra = 1         model = Image      @admin.register(Product)     class ProductModelAdmin(admin.ModelAdmin):         inlines = (ImageAdminInline,)         fields = ('title', 'price')      @admin.register(Image)     class ImageModelAdmin(admin.ModelAdmin):         fields = ('src', 'product')<\/code><\/pre>\n
So far we have two simple models and basic\u00a0ModelAdmins<\/code>\u00a0with an\u00a0InlineModel<\/code>.<\/p>\n
Standard ModelAdmin With Inline<\/figcaption><\/figure>\n
How should we squeeze that Inline above or in between the two fields of the\u00a0ProductModelAdmin<\/code>?<\/p>\n
I suppose, you are familiar with the\u00a0added field<\/u><\/a>\u00a0concept in\u00a0ModelAdminForm<\/code>. You can create a method in the\u00a0ModelAdmin<\/code>\u00a0to display the response of the method in the form as a readonly field.
Keep in mind, that the rendering sequence of the\u00a0ModelAdmin<\/code>\u00a0will create the\u00a0InlineModels<\/code>\u00a0first, then render\u00a0AdminForm<\/code>\u00a0and after that render the\u00a0InlineForms<\/code>.<\/p>\n
We can use that to rearrange the order of Inlines and fields.<\/p>\n
from django.contrib import admin from django.contrib.admin.options import TabularInline from django.template.loader import get_template from .models import Image, Product  class ImageAdminInline(TabularInline):  extra = 1  model = Image  @admin.register(Product) class ProductModelAdmin(admin.ModelAdmin):   inlines = (ImageAdminInline,)   fields = ('image_inline', 'title', 'price')   readonly_fields= ('image_inline',) # method as readonly field    def image_inline(self, *args, **kwargs):     context = getattr(self.response, 'context_data', None) or {}     inline = context['inline_admin_formset'] = context['inline_admin_formsets'].pop(0)     return get_template(inline.opts.template).render(context, self.request)    def render_change_form(self, request, *args, **kwargs):     self.request = request     self.response = super().render_change_form(request, *args, **kwargs)     return self.response<\/code><\/pre>\n
We use the\u00a0render_change_form<\/code>\u00a0to get the objects\u00a0request<\/code>\u00a0and\u00a0response<\/code>.
We use those objects in the\u00a0image_inline<\/code>\u00a0method to take one\u00a0inline_formset<\/code>\u00a0from the list of\u00a0inline_admin_formsets<\/code>\u00a0that have not been processed yet, and render\u00a0InlineFormset<\/code>.<\/p>\n
After the\u00a0change_form<\/code>\u00a0rendering the remaining\u00a0inline_admin_formsets<\/code>\u00a0will be rendered, in case if the\u00a0ModelAdmin<\/code>\u00a0still has some.<\/p>\n
Now we can use the method\u00a0image_inline<\/code>\u00a0to determine the position of our\u00a0InlineFormset<\/code>.
With the code-snippet above the inline element will be placed above all other fields.<\/p>\n
ModelAdminForm with Inline on the top<\/figcaption><\/figure>\n
When we rearrange the fields this way the inline is rendered between the fields:<\/p>\n
@admin.register(Product) class ProductModelAdmin(admin.ModelAdmin):   inlines = ImageAdminInline,   fields = 'title','image_inline', 'price'   readonly_fields= 'image_inline',  # method as readonly field<\/code><\/pre>\n
Of course Django admin adds a lable infront of the Inline with the name of the method, but that can be easily removed by some simple CSS in\u00a0Media<\/code>\u00a0attribute of\u00a0ProductModelAdmin<\/code>.<\/p>\n
ModelAdminForm has inline in the middle<\/figcaption><\/figure>\n
This solution has one fatal error! Every Django ModelAdmin is singelton, that is why we can not use ModelAdmin.self as a container in\u00a0<\/strong>render_change_form<\/code>!<\/p>\n
It is possible to change the ModelAdmins singleton\u00b4s behavior with a Mixin, staying inline with the concept of Djangos GCBV. We will take a closer look at it in my next article.<\/p>\n
It simply means, that we can’t use the instance of the\u00a0ModelAdmin<\/code>\u00a0as a container to save our\u00a0request<\/code>\u00a0and\u00a0response<\/code>.
The solution is to save those objects in the\u00a0AdminForm<\/code>\u00a0instance.<\/p>\n
@admin.register(Product)     class ProductModelAdmin(admin.ModelAdmin):         inlines = (ImageAdminInline,)         fields = ('title', 'image_inline', 'price')         readonly_fields= ('image_inline',)  # we set the method as readonly field          def image_inline(self, obj=None, *args, **kwargs):             context = obj.response['context_data']             inline = context['inline_admin_formset'] = context['inline_admin_formsets'].pop(0)             return get_template(inline.opts.template).render(context, obj.request)          def render_change_form(self, request, context, *args, **kwargs):             instance = context['adminform'].form.instance  # get the model instance from modelform             instance.request = request             instance.response = super().render_change_form(request, context, *args, **kwargs)             return instance.response<\/code><\/pre>\n
The argument\u00a0obj<\/code>\u00a0is not always given in\u00a0render_change_form<\/code>\u00a0(i.e. add new object). That is why we have to get it from the\u00a0ModelForm<\/code>, which is wrapped into the\u00a0AdminForm<\/code>.<\/p>\n
Now we can set our request and response as attributes of the\u00a0ModelForm<\/code>\u00a0instance and use those in\u00a0image_inline<\/code>.<\/p>\n
Summing up the above: you don’t have to install another battery to your project to solve a simple problem. Sometimes you need to dig deep enough into the framework that you use, and find a simple, short and quick solution.<\/h4>\n\n
I\u00b4d like to thank Martin Achenrainer the intern of wPsoft for contributing to this article and translating it.<\/p>\n<\/div>\n<\/div>\n<\/div>\n
<\/div>\n

 \u0441\u0441\u044b\u043b\u043a\u0430 \u043d\u0430 \u043e\u0440\u0438\u0433\u0438\u043d\u0430\u043b \u0441\u0442\u0430\u0442\u044c\u0438  https:\/\/habr.com\/ru\/articles\/659173\/<\/a>
<\/br><\/br><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[],"tags":[],"class_list":["post-393506","post","type-post","status-publish","format-standard","hentry"],"_links":{"self":[{"href":"https:\/\/savepearlharbor.com\/index.php?rest_route=\/wp\/v2\/posts\/393506","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/savepearlharbor.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/savepearlharbor.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/savepearlharbor.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/savepearlharbor.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=393506"}],"version-history":[{"count":0,"href":"https:\/\/savepearlharbor.com\/index.php?rest_route=\/wp\/v2\/posts\/393506\/revisions"}],"wp:attachment":[{"href":"https:\/\/savepearlharbor.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=393506"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/savepearlharbor.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=393506"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/savepearlharbor.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=393506"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}