使用 django-simple-captcha 的方法

• 2019 年 10 月 10 日
• 筆記

Installation

1. Install django-simple-captcha via pip: pip install django-simple-captcha
2. Add captcha to the INSTALLED_APPS in your settings.py
3. Run python manage.py migrate
4. Add an entry to your urls.py:

urlpatterns += [          url(r'^captcha/', include('captcha.urls')),      ]

Note: PIL and Pillow require that image libraries are installed on your system. On e.g. Debian or Ubuntu, you’d need these packages to compile and install Pillow:

apt-get -y install libz-dev libjpeg-dev libfreetype6-dev python-dev

Adding to a Form

Using a CaptchaField is quite straight-forward:

Define the Form

To embed a CAPTCHA in your forms, simply add a CaptchaField to the form definition:

from django import forms  from captcha.fields import CaptchaField    class CaptchaTestForm(forms.Form):      myfield = AnyOtherField()      captcha = CaptchaField()

…or, as a ModelForm:

from django import forms  from captcha.fields import CaptchaField    class CaptchaTestModelForm(forms.ModelForm):      captcha = CaptchaField()      class Meta:          model = MyModel

Validate the Form

In your view, validate the form as usual. If the user didn’t provide a valid response to the CAPTCHA challenge, the form will raise a ValidationError:

def some_view(request):      if request.POST:          form = CaptchaTestForm(request.POST)            # Validate the form: the captcha field will automatically          # check the input          if form.is_valid():              human = True      else:          form = CaptchaTestForm()        return render_to_response('template.html',locals())

Passing arguments to the field

CaptchaField takes a few optional arguements:

• output_format will let you format the layout of the rendered field. Defaults to the value defined in : CAPTCHA_OUTPUT_FORMAT.
• id_prefix Optional prefix that will be added to the ID attribute in the generated fields and labels, to be used when e.g. several Captcha fields are being displayed on a same page. (added in version 0.4.4)
• generator Optional callable or module path to callable that will be used to generate the challenge and the response, e.g. generator='path.to.generator_function' or generator=lambda: ('LOL', 'LOL'), see also Generators and modifiers. Defaults to whatever is defined in settings.CAPTCHA_CHALLENGE_FUNCT.

Example usage for ajax form

An example CAPTCHA validation in AJAX:

from django.views.generic.edit import CreateView  from captcha.models import CaptchaStore  from captcha.helpers import captcha_image_url  from django.http import HttpResponse  import json    class AjaxExampleForm(CreateView):      template_name = ''      form_class = AjaxForm        def form_invalid(self, form):          if self.request.is_ajax():              to_json_response = dict()              to_json_response['status'] = 0              to_json_response['form_errors'] = form.errors                to_json_response['new_cptch_key'] = CaptchaStore.generate_key()              to_json_response['new_cptch_image'] = captcha_image_url(to_json_response['new_cptch_key'])                return HttpResponse(json.dumps(to_json_response), content_type='application/json')        def form_valid(self, form):          form.save()          if self.request.is_ajax():              to_json_response = dict()              to_json_response['status'] = 1                to_json_response['new_cptch_key'] = CaptchaStore.generate_key()              to_json_response['new_cptch_image'] = captcha_image_url(to_json_response['new_cptch_key'])                return HttpResponse(json.dumps(to_json_response), content_type='application/json')

And in javascript your must update the image and hidden input in form

Example usage ajax refresh button

html:

<form action='.' method='POST'>      {{ form }}      <input type="submit" />      <button class='js-captcha-refresh'></button>  </form>

javascript:

$('.js-captcha-refresh').click(function(){      $form = $(this).parents('form');        $.getJSON($(this).data('url'), {}, function(json) {          // This should update your captcha image src and captcha hidden input      });        return false;  });

Example usage ajax refresh

javascript:

$('.captcha').click(function () {      $.getJSON("/captcha/refresh/", function (result) {          $('.captcha').attr('src', result['image_url']);          $('#id_captcha_0').val(result['key'])      });    });