重定向后表单未在模板中呈现（django）

Question

我有一个处理和打印表单的视图及其模板。该表单有一个 ChoiceField，它将模型列表作为选项。这是我的观点、模板和表格：

*views.py*
def index(request):
    form = dbForm()
    print "form is: ", form
    return render(request, 'Directories/index.html', {'form':form})

*index.html*
<div id="content" align="center">                   
<form action="" method="get">   {% csrf_token %}
    {{form.as_p}}  
    <input type="submit" value="Edit" name="_add" />
</form>

*forms.py*
model_classes = []

class dbForm(forms.Form):
    model_classes_field = forms.ChoiceField(choices=models())

def models():
    apps = get_app('Directories')
    for model in get_models(apps):
        model_classes.append( (model._meta.verbose_name, model._meta.db_table), )
    return model_classes

提交的模型选择被发送到另一个视图，其中 ModelForm 显示模型的字段并期望提交每个字段的数据。然后将提交的数据存储在数据库中，并将用户重定向回索引以从头开始。这是视图、模板和表单：

*views.py*
def modelUpdate(request):
    if 'update' in request.POST: # If the form has been submitted...
        form_class = get_dynamic_form(request.GET['model_classes_field']) 
        form = form_class(request.POST)         
        if form.is_valid(): # All validation rules pass
            row = form.save() #saves into database 
            return render(request, 'Directories/index.html')
        else:
            print "form errors: ", form.errors
            return HttpResponse('ERROR -- Return to form submission')


*create.html*
<form action="" method="post"> {% csrf_token %}
{% for f_name in field_names %} 
    {% if not forloop.first %}      
        {{f_name}}: <input id="edit-{{f_name}}" type="text" name={{f_name}} /><br />
    {% endif %}
{% endfor %}<br />
<input type="submit" name="update" value="Update" />
<input type="reset" name="Clear" value="Clear" />
</form>

*forms.py*
#create a ModelForm using a dynamic model
def get_dynamic_form(c_model):
    model_class = get_model('Directories', c_model)
    class ObjForm(forms.ModelForm ):
        class Meta:
            model = model_class
return ObjForm

在将数据保存到数据库后将表单重定向回 index.html return render(request, 'Directories/index.html') 时会出现问题。发生的情况是 index.html 根本不显示表单 {{form.as_p}}。虽然当我在我的服务器（Apache）error.log 中检查print "form is: ", form 时，我的表单是按原样打印的。

我不明白为什么重定向发生后数据没有在我的模板中呈现，但它们仍然正确显示在我的服务器日志中。

Answer 1

您应该像在index 视图中那样将form 实例传递给您的模板。您的代码应更新为

def modelUpdate(request):
    if 'update' in request.POST: # If the form has been submitted...
        form_class = get_dynamic_form(request.GET['model_classes_field']) 
        form = form_class(request.POST)         
        if form.is_valid(): # All validation rules pass
            row = form.save() #saves into database 
            #------------------------------------------------v pass it to template
            return render(request, 'Directories/index.html', {'form': form})
        else:
            print "form errors: ", form.errors
            return HttpResponse('ERROR -- Return to form submission')