뷰(Views)와 템플릿(Templates)
polls/view.py
from .models import *
from django.shortcuts import render
def index(request):
latest_question_list = Question.objects.order_by('-pub_date')[:5]
context = {'first_question': latest_question_list[0]}
return render(request, 'polls/index.html', context)Django Shell
>>> from polls.models import *
>>> Question.objects.order_by('-pub_date')[:5]
>>> print(Question.objects.order_by('-pub_date')[:5].query)
SELECT "polls_question"."id", "polls_question"."question_text", "polls_question"."pub_date" FROM "polls_question" ORDER BY "polls_question"."pub_date" DESC LIMIT 5polls/templates/polls/index.html
<ul>
<li>{{first question}}</li>
<ul>템플릿(Templates)에서 제어문 사용하기
polls/templates/polls/index.html
{% if questions %}
<ul>
{% for question in questions %}
<li>{{question}}</li>
{% endfor %}
</ul>
{% else %}
<p>no questions</p>
{% endif %}polls/views.py
from .models import *
from django.shortcuts import render
def index(request):
latest_question_list = Question.objects.order_by('-pub_date')[:5]
context = {'questions': latest_question_list}
#context = {'questions': []}
return render(request, 'polls/index.html', context)상세(detail) 페이지 만들기
polls/views.py
def detail(request, question_id):
question = Question.objects.get(pk=question_id)
return render(request, 'polls/detail.html', {'question': question})polls/urls.py
from django.urls import path
from . import views
urlpatterns = [
path('', views.index, name='index'),
path('some_url', views.some_url),
path('<int:question_id>/', views.detail, name='detail'),
]polls/templates/polls/detail.html
<h1>{{ question.question_text }}</h1>
<ul>
{% for choice in question.choice_set.all %}
<li>{{ choice.choice_text }}</li>
{% endfor %}
</ul>상세(detail) 페이지로 링크 추가하기
polls/urls.py
from django.urls import path
from . import views
app_name = 'polls'
urlpatterns = [
path('', views.index, name='index'),
path('some_url', views.some_url),
path('<int:question_id>/', views.detail, name='detail'),
]polls/templates/polls/index.html
{% if questions %}
<ul>
{% for question in questions %}
<li><a href="{% url 'polls:detail' question.id %}">{{ question.question_text }}</a></li>
{% endfor %}
<ul>
{% else %}
<p>no questions</p>
{% endif %}404 에러 처리하기
get은 찾을 수 없으면 500 에러가 발생함 -> 404로 바꿔야함
polls/views.py
from models.py import *
from django.http import HttpResponse
from django.http import Http404
from django.shortcuts import render , get_object_or_404
...
def detail(request, question_id):
"""
try:
question = Question.objects.get(pk=question_id)
except Question.DoesNotExist:
raise Http404("Question does not exist")
"""
question = get_object_or_404(Question, pk=question_id)
return render(request, 'polls/detail.html', {'question': question})폼(Forms)
polls/views.py
def vote(request, question_id):
question = get_object_or_404(Question, pk=question_id)
try:
selected_choice = question.choice_set.get(pk=request.POST['choice'])
except (KeyError, Choice.DoesNotExist):
return render(request, 'polls/detail.html', {'question': question, 'error_message': '선택이 없습니다.'})
else:
selected_choice.votes += 1
selected_choice.save()
return HttpResponseRedirect(reverse('polls:index'))polls/urls.py
from django.urls import path
from . import views
app_name = 'polls'
urlpatterns = [
path('', views.index, name='index'),
path('<int:question_id>/', views.detail, name='detail'),
path('<int:question_id>/vote/', views.vote, name='vote'),
]polls/templates/polls/detail.html
<form action="{% url 'polls:vote' question.id %}" method="post">
{% csrf_token %}
<h1>{{ question.question_text }}</h1>
{% if error_message %}
<p><strong>{{ error_message }}</strong></p>
{% endif %}
{% for choice in question.choice_set.all %}
<input type="radio" name="choice" id="choice{{ forloop.counter }}" value="{{ choice.id }}">
<label for="choice{{ forloop.counter }}">
{{ choice.choice_text }}
</label>
<br>
{% endfor %}
<input type="submit" value="Vote">
</form>에러 방어하기
polls/views.py
브라우저의 오류를 대비해야한다 -> 브라우저에서 올라가는 데이터가 삭제되거나 바뀔수 있기 때문
def vote(request, question_id):
question = get_object_or_404(Question, pk=question_id)
try:
selected_choice = question.choice_set.get(pk=request.POST['choice'])
except (KeyError, Choice.DoesNotExist):
return render(request, 'polls/detail.html', {'question': question, 'error_message': f"선택이 없습니다. id={request.POST['choice']}"})
else:
selected_choice.votes += 1
selected_choice.save()
return HttpResponseRedirect(reverse('polls:results', args=(question.id,)))polls/views.py
A서버와 B서버에서 동시에 명령을 주었을 경우 하나만 실행될 수 있음, 이를 방어
from django.urls import reverse
from django.db.models import F
def vote(request, question_id):
question = get_object_or_404(Question, pk=question_id)
try:
selected_choice = question.choice_set.get(pk=request.POST['choice'])
except (KeyError, Choice.DoesNotExist):
return render(request, 'polls/detail.html', {'question': question, 'error_message': f"선택이 없습니다. id={request.POST['choice']}"})
else:
# A서버에서도 Votes = 1
# B서버에서도 Votes = 1
selected_choice.votes = F('votes') + 1
selected_choice.save()
return HttpResponseRedirect(reverse('polls:index'))결과(result) 조회 페이지
302 Redirect
polls/views.py
from django.shortcuts import get_object_or_404, render
...
def vote(request, question_id):
...
else:
selected_choice.votes = F('votes') + 1
selected_choice.save()
return HttpResponseRedirect(reverse('polls:result', args=(question.id,)))
def result(request, question_id):
question = get_object_or_404(Question, pk=question_id)
return render(request, 'polls/result.html', {'question': question})polls/templates/polls/result.html
<h1>{{ question.question_text }}</h1><br>
{% for choice in question.choice_set.all %}
<label>
{{ choice.choice_text }} -- {{ choice.votes }}
</label>
<br>
{% endfor %}polls/urls.py
from django.urls import path
from . import views
app_name = 'polls'
urlpatterns = [
path('', views.index, name='index'),
path('<int:question_id>/', views.detail, name='detail'),
path('<int:question_id>/vote/', views.vote, name='vote'),
path('<int:question_id>/result/', views.result, name='result'),
]Django Admin의 편집 페이지 커스터마이징
models.py의 pub_date = models.DateTimeField()으로 바꿔서 기본값 없애줌
polls/admin.py
from django.contrib import admin
from .models import Question, Choice
# Register your models here.
# CRUD Create Read Update Delete
admin.site.register(Choice)
# 좌우로 보이기 위해 TabularInline 사용
class ChoiceInline(admin.TabularInline):
model = Choice
extra = 3
class QuestionAdmin(admin.ModelAdmin):
fieldsets = [
('질문 섹션', {'fields': ['question_text']}),
# 숨기고 싶으면 collapse
('생성일', {'fields': ['pub_date'], 'classes': ['collapse']}),
]
readonly_fields = ['pub_date']
# Choice 와 함께 편집하기 위해
inlines = [ChoiceInline]
admin.site.register(Question, QuestionAdmin)Django Admin의 목록 페이지 커스터마이징
polls/models.py
import datetime
from django.db import models
from django.utils import timezone
from django.contrib import admin
class Question(models.Model):
question_text = models.CharField(max_length=200, verbose='질문')
pub_date = models.DateTimeField(auto_now_add=True, verbose='생성일')
# 목록에서 표시되는 이름을 보기 위해
@admin.display(boolean=True, description='최근생성(하루기준)')
def was_published_recently(self):
return self.pub_date >= timezone.now() - datetime.timedelta(days=1)
def __str__(self):
return f'제목: {self.question_text}, 날짜: {self.pub_date}polls/admin.py
from django.contrib import admin
from .models import Choice, Question
admin.site.register(Choice)
class ChoiceInline(admin.TabularInline):
model = Choice
extra = 3
class QuestionAdmin(admin.ModelAdmin):
fieldsets = [
('질문 섹션', {'fields': ['question_text']}),
('생성일', {'fields': ['pub_date'], 'classes': ['collapse']}),
]
readonly_fields = ['pub_date']
inlines = [ChoiceInline]
list_display = ['question', 'pub_date', 'was_published_recently']
# 검색을 하기위해
list_filter = ['pub_date']
search_fields = ['question_text', 'choice__choice_text']
admin.site.register(Question, QuestionAdmin)
새싹 개발자