{"id":7244,"date":"2021-01-11T18:25:11","date_gmt":"2021-01-11T17:25:11","guid":{"rendered":"https:\/\/blog.via-internet.de\/?p=7244"},"modified":"2021-10-22T12:08:07","modified_gmt":"2021-10-22T10:08:07","slug":"django-cookbook-2","status":"publish","type":"post","link":"https:\/\/via-internet.de\/blog\/2021\/01\/11\/django-cookbook-2\/","title":{"rendered":"Django | Cookbook"},"content":{"rendered":"\n

Installation<\/h2>\n\n\n\n

Install current Version (3.2.8)<\/h3>\n\n\n\n
\u276f pip install django==3.2.8<\/pre>\n\n\n\n
Install next Version (4.0)<\/h3>\n\n\n\n
\u276f pip install --pre django<\/pre>\n\n\n\n
Check installed version<\/h3>\n\n\n\n
\u276f python -m django --version<\/pre>\n\n\n\n
\u276f django-admin.exe version<\/pre>\n\n\n\n
First steps<\/h2>\n\n\n\n
The following steps are based on a summary of the Django Tutorial<\/a><\/p>\n\n\n\n
Create project<\/h3>\n\n\n\n
django-admin startproject main\ncd working_with_django\npython manage.py migrate\npython manage.py runserver 8080\npython manage.py startapp app_base<\/pre>\n\n\n\n
Create view<\/h3>\n\n\n\n
Create view in app_base\/views.py<\/strong><\/h4>\n\n\n\n
from django.http import HttpResponse\n\ndef index(request):\n    return HttpResponse(\"Hello, world. You're at the polls index.\")<\/pre>\n\n\n\n
Add view to  app_base\/urls.py<\/strong><\/h4>\n\n\n\n
from django.urls import path\nfrom . import views\n\nurlpatterns = [\n    path('', views.index, name='index'),\n]<\/pre>\n\n\n\n
Add urls to project main\/urls.py<\/strong><\/h4>\n\n\n\n
from django.contrib import admin\nfrom django.urls import include, path\n\nurlpatterns = [\n    path('admin\/', admin.site.urls),\n    path('app_base\/', include('app_base.urls')),\n]<\/pre>\n\n\n\n
Create admin user<\/h3>\n\n\n\n
$ python manage.py createsuperuser\nUsername (leave blank to use 'user'): admin\nEmail address: admin@localhost\nPassword: \nPassword (again): \nSuperuser created successfully.<\/pre>\n\n\n\n
Create data and database<\/h3>\n\n\n\n
Create database model in app_base\/models.py<\/strong><\/h4>\n\n\n\n
from django.db import models\n\nclass Question(models.Model):\n    question_text = models.CharField(max_length=200)\n    pub_date = models.DateTimeField('date published')\n\nclass Choice(models.Model):\n    question = models.ForeignKey(Question, on_delete=models.CASCADE)\n    choice_text = models.CharField(max_length=200)\n    votes = models.IntegerField(default=0)<\/pre>\n\n\n\n
Activating models in main\/settings.py<\/strong><\/h4>\n\n\n\n
INSTALLED_APPS = [\n    'app_base.apps.AppBaseConfig',\n\n    'django.contrib.admin',\n    'django.contrib.auth',\n    'django.contrib.contenttypes',\n    'django.contrib.sessions',\n    'django.contrib.messages',\n    'django.contrib.staticfiles',\n]<\/pre>\n\n\n\n
$ python manage.py makemigrations app_base\n$ python manage.py sqlmigrate app_base 0001<\/pre>\n\n\n\n
Make  app modifiable in the admin  (app_base\/admin.py<\/strong>)<\/h4>\n\n\n\n
from django.contrib import admin\nfrom .models import Question\n\nadmin.site.register(Question)<\/pre>\n\n\n\n
Writing more views <\/h3>\n\n\n\n
Create views in app_base\/views.py<\/strong><\/h4>\n\n\n\n
def detail(request, question_id):\n    return HttpResponse(\"You're looking at question \n\ndef results(request, question_id):\n    response = \"You're looking at the results of question \n    return HttpResponse(response \n\ndef vote(request, question_id):\n    return HttpResponse(\"You're voting on question \n<\/pre>\n\n\n\n
Add new views into app_base\/urls.py<\/code><\/h4>\n\n\n\n
from django.urls import path\nfrom . import views\n\nurlpatterns = [\n    path('', views.index, name='index'),\n\n    path('<int:question_id>\/', views.detail, name='detail'),\n    path('<int:question_id>\/results\/', views.results, name='results'),\n    path('<int:question_id>\/vote\/', views.vote, name='vote'),\n]<\/pre>\n\n\n\n
Add template in app_base\/templates\/polls\/index.html<\/h4>\n\n\n\n
{\n    <ul>\n    {\n        <li><a href=\"\/polls\/{{ question.id }}\/\">{{ question.question_text }}<\/a><\/li>\n    {\n    <\/ul>\n{\n    <p>No polls are available.<\/p>\n{\n\n\n\n
Modify view in app_base\/views.py<\/strong><\/h4>\n\n\n\n
from django.shortcuts import render\n...\ndef index(request):\n    latest_question_list = Question.objects.order_by('-pub_date')[:5]\n    context = {'latest_question_list': latest_question_list}\n    return render(request, 'polls\/index.html', context)<\/pre>\n\n\n\n
Raising a 404 error in app_base\/views.py<\/h3>\n\n\n\n
from django.http import HttpResponse\nfrom django.shortcuts import render, get_object_or_404\n\nfrom .models import Question\n# ...\ndef detail(request, question_id):\n    question = get_object_or_404(Question, pk=question_id)\n    return render(request, 'polls\/detail.html', {'question': question})<\/pre>\n\n\n\n
Create template app_base\/templates\/polls\/detail.html<\/code><\/h3>\n\n\n\n
<h1>{{ question.question_text }}<\/h1>\n<ul>\n{\n    <li>{{ choice.choice_text }}<\/li>\n{\n<\/ul><\/pre>\n\n\n\n
Removing hardcoded URLs in app_base\/templates\/polls\/index.html<\/code><\/h3>\n\n\n\n
<li>\n   <a href=\"{\n<\/li><\/pre>\n\n\n\n
The way this works is by looking up the URL definition as specified in the app_base\/urs.py<\/p>\n\n\n\n
...\n# the 'name' value as called by the {\npath('<int:question_id>\/', views.detail, name='detail'),\n...<\/pre>\n\n\n\n
Namespacing URL names in app_base\/urls.py<\/code><\/h3>\n\n\n\n
app_name = 'app_base'\n\nurlpatterns = [\n...<\/pre>\n\n\n\n
Then, modify link in app_base\/templates\/polls\/index.html<\/code><\/p>\n\n\n\n
from url ‘detail’<\/strong> to url ‘app_base:detail’<\/strong><\/p>\n\n\n\n
<li>\n    <a href=\"{\n<\/li><\/pre>\n\n\n\n
Use generic views: Less code is better<\/h3>\n\n\n\n
Create class in a<\/code>pp_views\/views.py<\/h4>\n\n\n\n
class HomeView(generic.TemplateView):\n    template_name = 'index.html'<\/pre>\n\n\n\n
Create template app_views\/templates\/index.html<\/code><\/h4>\n\n\n\n
<h1>App Views:<\/h1>\nWelcome<\/pre>\n\n\n\n
Modify app_views\/urls.py<\/code><\/h4>\n\n\n\n
urlpatterns = [\n    path('', views.HomeView.as_view(), name='home'),\n]<\/pre>\n\n\n\n
Add another app to main project<\/h3>\n\n\n\n
Create app<\/h4>\n\n\n\n
$ python manage.py startapp app_view\n<\/pre>\n\n\n\n
Modify main\/urls.py<\/code><\/h4>\n\n\n\n
urlpatterns = [\n    path('admin\/',     admin.site.urls),\n    path('app_base\/',  include('app_base.urls')),\n    path('app_views\/', include('app_views.urls')),\n]<\/pre>\n\n\n\n
Add data model in app_views\/models.py<\/code><\/h4>\n\n\n\n
from django.db import models\n\nclass DataItem(models.Model):\n    text = models.CharField(max_length=200)\n    data = models.IntegerField(default=0)\n\n    def __str__(self):\n        return self.text<\/pre>\n\n\n\n
Register data in app_views\/admin.py<\/code><\/h4>\n\n\n\n
from django.contrib import admin\nfrom .models import DataItem\n\nadmin.site.register(DataItem)<\/pre>\n\n\n\n
Activate models<\/h4>\n\n\n\n
$ python manage.py makemigrations app_views\n$ python manage.py sqlmigrate app_views 0001\n$ python manage.py migrate app_views<\/pre>\n\n\n\n
<\/p>\n\n\n\n
Navigation \/ Redirection<\/h2>\n\n\n\n
Set root page of Django project<\/h3>\n\n\n\n
When accessing your Django project, the root page will normaly doesn’n show your app homepage.<\/p>\n\n\n\n
To change this, you hate to modiy the url handling.<\/p>\n\n\n\n
In the following sample, replace <appname> with the name of your app<\/p>\n\n\n\n
Define a redirection view in your app (\/<appname>\/urls.py<\/strong>)<\/h4>\n\n\n\n
def redirect_to_home(request):\n    return redirect('\/<appname>')<\/pre>\n\n\n\n
Define path in the global urls.py  (\/main\/urls.py<\/strong>)<\/h4>\n\n\n\n
from django.contrib import admin\nfrom django.urls import include, path\nfrom django.shortcuts import redirect\n\nfrom <appname> import views\n\nurlpatterns = [\n    path('',            views.redirect_to_home, name='home'),\n    path('<appname>\/',  include('<appname>.urls')),\n    path('admin\/',      admin.site.urls)\n]<\/pre>\n\n\n\n
Highlight current page in navigation menu<\/p>\n\n\n\n
<div class=\"list-group\">\n    <a href=\"{\n            Basic Upload\n    <\/a>\n    <a href=\"{\n            Progress Bar Upload\n    <\/a>\n<\/div><\/pre>\n\n\n\n
Using PostgresSQL Database<\/h2>\n\n\n\n
Install PostgresSQL<\/h3>\n\n\n\n
Create Superuser<\/h3>\n\n\n\n
createuser.exe --interactive --pwprompt<\/pre>\n\n\n\n
Logging<\/h2>\n\n\n\n
<\/h3>\n\n\n\n\n\n
Additional reading<\/h2>\n\n\n\n
Tutorials<\/h3>\n\n\n\n