在Django視圖中跟蹤對象ID

Question

我的視圖是一個基於函數的視圖（這是一個遺留問題，由於內聯formset的使用，更容易保持它的方式而不是CBV）。我的目標是能夠爲模型對象Article.objects.get（user = user）.latest（「id」）和POST方法渲染ModelForm，更新已渲染的同一個對象。問題是ModelForm「不記得」它所對應的對象。將關於對象的信息傳遞給POST方法中使用的視圖的正確方法是什麼？

下面是views.py的簡化版本和urls.py

views.py

from django.contrib.auth.models import User 
from django.shortcuts import render_to_response 
from django.template import RequestContext 
from specify.models import Article 
from specify.forms import ArticleForm 

def index(request): 

    user = User.objects.get(username=request.user.username) 

    if request.method == "POST": 
     a_form = ArticleForm(request.POST, instance= *???*) 
     a_form.save() 
    else: 
     a = Article.objects.get(user=user).latest("id") 
     a_form = ArticleForm(instance=a) 

    return render_to_response(
     "specify/index.html", 
     { 
      "a_form" : a_form, 
     }, 
     context_instance=RequestContext(request) 
    ) 

urls.py

from django.conf.urls import patterns, url 
from specify import views 

urlpatterns = patterns('', 
    url(r'^$', views.index, name='index') 
) 

EDIT1：加入models.py和forms.py

models.py

from django.db import models 

class Article(models.Model): 
    pub_date = models.DateField() 
    headline = models.CharField(max_length=200) 
    content = models.TextField() 

forms.py

from django.forms import ModelForm 
from specify.models import Article 

class ArticleForm(ModelForm): 
    class Meta: 
     model = Article 
     fields = ['pub_date', 'headline', 'content'] 

Answer 1

首先，你應該通過文章編號，以模板，在view.py

def index(request): 

user = User.objects.get(username=request.user.username) 

if request.method == "POST": 
    #Explained later 
else: 
    a = Article.objects.get(user=user).latest("id") 
    a_form = ArticleForm(instance=a) 
    article_id = a.id 

return render_to_response(
    "specify/index.html", 
    { 
     "a_form" : a_form, 
     "article_id": article_id, 
    }, 
    context_instance=RequestContext(request) 
) 

第二模板中的表單HTML元素的內部，你應該處理您的文章編號

{% if article_id %} 
<input type="hidden" value='{{ article_id }}' id='article_id' name='article_id'/> 
{% endif %} 

第三，在更新處理中，您應該執行以下操作：

if request.method == "POST":    
    article_id = request.POST.get('article_id') # You are getting passed article id 
    a = Article.objects.get(pk=article_id)  # You are getting instance by id 
    a_form = ArticleForm(request.POST, instance=a) 
    a_form.save() 

嘗試上面的步驟，如果你有問題發表評論