Question

我在限制formset中的可选选项时遇到问题。我有以下模型：员工，部门，项目，项目类型，成员资格和角色。员工可以在表单集中添加/删除他们为给定部门项目播放的角色，表单应该将可选项目限制为仅属于该员工所属部门的那些项目。

模型：

class Department(models.Model):
    name = models.CharField(max_length=20)
    def __unicode__(self):
    return self.name

class Employee(models.Model):
    fname = models.CharField(max_length=15)
    department = models.ForeignKey(Department)
    def __unicode__(self):
        return self.fname

class Projecttype(models.Model):
    name = models.CharField(max_length=20)
    def __unicode__(self):
        return self.name

class Project(models.Model):
    projecttype = models.ForeignKey(Projecttype)
    department = models.ForeignKey(Department)
    members = models.ManyToManyField(Employee, through='Membership')
    def __unicode__(self):
       return "%s > %s" % (self.department, self.projecttype)

class Role(models.Model):
    name = models.CharField(max_length=20)
    def __unicode__(self):
       return self.name

class Membership(models.Model):
    project = models.ForeignKey(Project, null=True)
    department = models.ForeignKey(Department)
    employee = models.ForeignKey(Employee)
    role = models.ManyToManyField(Role, blank=True, null=True)
    class Meta:
        unique_together = (("project", "employee",),)

查看：

def employee_edit(request, employee_id):
    i = get_object_or_404(Employee, pk=employee_id)
    MembershipFormSet = modelformset_factory(Membership, exclude=('department', 'employee'),)
    f = MembershipFormSet(queryset=Membership.objects.filter(employee=i),)
    return render_to_response('gcs/edit.html', {'item': i, 'formset': f, }, context_instance=RequestContext(request))

现在，欧盟可以为任何部门项目选择一个角色。它的表现如下：

项目选项：

Projects.objects.all()

我想用这样的方式限制项目：LIMIT PROJECT CHOCIES TO：

Projects.objects.filter(department=i.department)

Answer 1

此Stack Overflow question非常相似。我喜欢Matthew的答案，你可以在一个通过闭包访问员工的函数中动态构建表单。在你的情况下，你需要像：

from django.http import HttpResponseRedirect

def make_membership_form(employee):
    """
    Returns a Membership form for the given employee, 
    restricting the Project choices to those in the 
    employee's department. 
    """
    class MembershipForm(forms.ModelForm):
        project = forms.ModelChoiceField(queryset=Projects.objects.filter(department=employee.department))
        class Meta:
            model = Membership
            excludes = ('department', 'employee',)
    return MembershipForm

def employee_edit(request, employee_id):
    employee = get_object_or_404(Employee, pk=employee_id)
    # generate a membership form for the given employee
    MembershipForm = make_membership_form(employee)
    MembershipFormSet = modelformset_factory(Membership, form=MembershipForm)

    if request.method == "POST":
        formset = MembershipFormSet(request.POST, queryset=Membership.objects.filter(employee=employee))
        if formset.is_valid():
            instances = formset.save(commit=False)
                for member in instances:
                    member.employee = employee
                    member.department = employee.department
                    member.save()
            formset.save_m2m()
            # redirect after successful update
            return HttpResponseRedirect("")
    else:
        formset = MembershipFormSet(queryset=Membership.objects.filter(employee=employee),)
    return render_to_response('testdb/edit.html', {'item': employee, 'formset': formset, }, context_instance=RequestContext(request))

Answer 2

修改

织补。所有打字因为我错过了代码的一部分;）。正如@Alasdair在评论中提到的那样，您已从表单中排除department，因此您可以使用Django对此进行限制。不过，我会留下原来的答案，以防万一它可以帮助别人。

根据您的具体情况，您只需要：

class MembershipForm(forms.ModelForm): def __init__(self, *args, **kwargs): super(MembershipForm, self).__init__(*args, **kwargs) self.fields['project'].queryset = self.fields['project'].queryset.filter(department_id=self.instance.department_id)

然后：

MembershipFormSet = modelformset_factory(Membership, form=MembershipForm, exclude=('department', 'employee'),)

原始答案（后代）

您不能在Django中对此进行限制，因为部门的值是可更改的，因此项目列表可能会根据当前选择的特定部门而有所不同。为了验证表单，您必须提供允许Django的所有可能项目，因此您唯一的选择是AJAX。

创建一个视图，该视图将返回一个JSON响应，该响应由供给视图的特定部门的项目组成。有点像：

from django.http import HttpResponse, HttpResponseBadRequest from django.shortcuts import get_list_or_404 from django.utils import simplejson def ajax_department_projects(request): department_id = request.GET.get('department_id') if department_id is None: return HttpResponseBadRequest() project_qs = Project.objects.select_related('department', 'project_type') projects = get_list_or_404(project_qs, department__id=department_id) data = [] for p in projects: data.append({ 'id': p.id, 'name': unicode(p), }) return HttpResponse(simplejson.dumps(data), mimetype='application/json')

然后，每当更改部门选择框时，创建一些JavaScript以获取此视图：

(function($){ $(document).ready(function(){ var $department = $('#id_department'); var $project = $('#id_project'); function updateProjectChoices(){ var selected = $department.val(); if (selected) { $.getJSON('/path/to/ajax/view/', {department_id: selected}, function(data, jqXHR){ var options = []; for (var i=0; i<data.length; i++) { output = '<option value="'+data[i].id+'"'; if ($project.val() == data[i].id) { output += ' selected="selected"'; } output += '>'+data[i].name+'</option>'; options.push(output); } $project.html(options.join('')); }); } } updateProjectChoices(); $project.change(updateProjectChoices); }); })(django.jQuery);

django：如何限制formset中的字段选择？

2 个答案: