Django Tutorial Part 4

21. 폼(Forms)

polls/views.py

from django.http import HttpResponse, HttpResponseRedirect
from django.urls import reverse

...
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     # 현재 앱의 views 가져오기

app_name = 'polls'

urlpatterns = [
    path('some_url',views.some_url),
    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>

 

 

22. 에러 방어하기 1

vote를 누르기 직전에 choice가 사라지는 경우가 존재합니다.

 

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': f"선택이 없습니다. id={request.POST['choice']}"})
    else:
        selected_choice.votes += 1
        selected_choice.save()
        return HttpResponseRedirect(reverse('polls:results', args=(question.id,)))

 

 

23. 에러 방어하기 2

완전히 동시에 여러 사람이 같은 choice에 vote한 경우가 존재합니다.

 

polls/views.py

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'))

 

 

24. 결과(result) 조회 페이지

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'),
]

 

 

25. Django Admin의 편집 페이지 커스터마이징

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]

admin.site.register(Question, QuestionAdmin)

 

 

26. 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')  

    @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_filter = ['pub_date']
    search_fields = ['question_text', 'choice__choice_text']
    
admin.site.register(Question, QuestionAdmin)