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代码下载：/Files/maplye/django/Study914.rarManipulator英语翻译成“操纵器”，你可以用它来创建，修改，验证你的一个实体对象，并结合FormWrapper可以自动生成页面上Html代码（注：FormWrapper是用来生成html代码，Manipulator使为FormWrapper提供数据和数据模型等）。
django系统已经带有两种Manipulator，一是AddManipulator，二是ChangeManipulator，我以前一直以为这是model的两个方法，还有ChangeManipulator我以为是为我的model更换一个Manipulator,其实他是两个不同的类。这两个类能够自动根据model来生成validation和save。AddManipulator和ChangeManipulator都是继承自Manipulator，不同的是ChangeManipulator带有一objectid的构造参数，并获取一object赋值给他的original_object属性，并在save方法使用修改对象，然后保存该对象。
关于这两种Manipulator的使用，可以参考django document:
http://www.djangoproject.com/documentation/forms/
除了django提供的两种Manipulator,我们还可以自定义Manipulator,这样我们定义自己的fields,validation,save等等。
如：
500)this.width=500'>from django import forms500)this.width=500'>500)this.width=500'>urgency_choices = (500)this.width=500'> (1, "Extremely urgent"),500)this.width=500'> (2, "Urgent"),500)this.width=500'> (3, "Normal"),500)this.width=500'> (4, "Unimportant"),500)this.width=500'>)500)this.width=500'>500)this.width=500'>class ContactManipulator(forms.Manipulator):500)this.width=500'> def __init__(self):500)this.width=500'> self.fields = (500)this.width=500'> forms.EmailField(field_name="from", is_required=True),500)this.width=500'> forms.TextField(field_name="subject", length=30, maxlength=200, is_required=True),500)this.width=500'> forms.SelectField(field_name="urgency", choices=urgency_choices),500)this.width=500'> forms.LargeTextField(field_name="contents", is_required=True),500)this.width=500'> )500)this.width=500'> def save(self): #500)this.width=500'>500)this.width=500'>.而且我们还可以定义带有初始化参数的custom Manipulator如：
500)this.width=500'>class ContactManipulator(forms.Manipulator):500)this.width=500'> def __init__(self,object_id=None):500)this.width=500'> self.object_id = object_id500)this.width=500'> self.fields = (500)this.width=500'> forms.EmailField(field_name="fromEmail", is_required=True),500)this.width=500'> forms.TextField(field_name="subject", length=30, maxlength=200, is_required=True),500)this.width=500'> forms.SelectField(field_name="urgency", choices=urgency_choices),500)this.width=500'> forms.LargeTextField(field_name="contents", is_required=True),500)this.width=500'> )500)this.width=500'>500)this.width=500'> def save(self, new_data):500)this.width=500'> fromemail = new_data["fromEmail"]500)this.width=500'> subject = new_data["subject"]500)this.width=500'> urgency = new_data["urgency"]500)this.width=500'> contents = new_data["contents"]500)this.width=500'> if self.object_id:500)this.width=500'> obj = Contact.objects.get(pk=int(self.object_id))500)this.width=500'> obj.fromEmail = fromemail500)this.width=500'> obj.subject = subject500)this.width=500'> obj.urgency = urgency;500)this.width=500'> obj.contents = contents;500)this.width=500'> else:500)this.width=500'> obj = Contact(fromEmail=fromemail, subject=subject, urgency=urgency,contents=contents)500)this.width=500'> obj.save()你看上面ContactManipulator的Manipulator就具有AddManipulator和ChangeManipulator两个的功能，那这个ContactManipulator应该怎么用呢
500)this.width=500'>#创建 500)this.width=500'>def contact_form(request):500)this.width=500'> manipulator = ContactManipulator()500)this.width=500'> if request.POST:500)this.width=500'> new_data = request.POST.copy()500)this.width=500'> errors = manipulator.get_validation_errors(new_data)500)this.width=500'> if not errors:500)this.width=500'> manipulator.do_html2python(new_data)500)this.width=500'>500)this.width=500'> manipulator.save(new_data)500)this.width=500'> return HttpResponseRedirect("/formapp/contact/")500)this.width=500'> else:500)this.width=500'> errors = new_data = {}500)this.width=500'> 500)this.width=500'> form = forms.FormWrapper(manipulator, new_data, errors)500)this.width=500'> return render_to_response('places/contact_form.html', {'form': form})500)this.width=500'>500)this.width=500'>#修改500)this.width=500'>def editcontact(request,contactid):500)this.width=500'> manipulator = ContactManipulator(contactid)500)this.width=500'> 500)this.width=500'> if request.POST:500)this.width=500'> new_data = request.POST.copy()500)this.width=500'> errors = manipulator.get_validation_errors(new_data)500)this.width=500'> if not errors:500)this.width=500'> manipulator.do_html2python(new_data)500)this.width=500'> manipulator.save(new_data)500)this.width=500'>500)this.width=500'> # Do a post-after-redirect so that reload works, etc.500)this.width=500'> return HttpResponseRedirect("/formapp/contact/1")500)this.width=500'> else:500)this.width=500'> errors = {} 500)this.width=500'> contact = Contact.objects.get(id = contactid)500)this.width=500'> new_data = contact.__dict__500)this.width=500'> 500)this.width=500'> form = forms.FormWrapper(manipulator, new_data,errors )500)this.width=500'> return render_to_response('places/contact_form.html', {'form': form}) 500)this.width=500'>以上是我在学习Manipulator时一些个人理解，暂时记录如此，以后我会更深入的了解他们，同时非常感谢limodou的解惑，他真是个热心人，向他学习！ |
