Django Form 不接受选择作为有效选择。看不出为什么答案

【问题标题】：Django Form doesn't accept selection as valid choice. Can't see whyDjango Form 不接受选择作为有效选择。看不出为什么
【发布时间】：2011-02-19 16:55:28
【问题描述】：

我制作了一个小表格，向用户询问某个位置（第一阶段），然后对位置进行地理编码并要求用户确认位置（第二阶段）。一切正常，但是，当我选择一个选项并尝试提交表单以进入第三阶段时，表单不接受选择并发出错误“选择一个有效的选择”。为什么？

我看不出我在哪里犯了错误。请让我知道我做错了什么。谢谢！

我的 forms.py

from django.http import HttpResponseRedirect
from django.contrib.formtools.wizard import FormWizard
from django import forms
from django.forms.widgets import RadioSelect
from geoCode import getLocation

class reMapStart(forms.Form):
    location = forms.CharField()
    CHOICES = [(x, x) for x in ("cars", "bikes")]
    technology = forms.ChoiceField(choices=CHOICES)


class reMapLocationConfirmation(forms.Form):    
   CHOICES = []
   locations = forms.ChoiceField(widget=RadioSelect(), choices = [])

class reMapData(forms.Form):
    capacity = forms.IntegerField()

class reMapWizard(FormWizard):    
    def render_template(self, request, form, previous_fields, step, context=None):
        if step == 1:
            location = request.POST.get('0-location')
            address, lat, lng, country = getLocation(location)
            form.fields['locations'].choices = [(x, x) for x in address]
        return super(reMapWizard, self).render_template(request, form, previous_fields, step, context)

def done(self, request, form_list):
    # Send an email or save to the database, or whatever you want with
    # form parameters in form_list
    return HttpResponseRedirect('/contact/thanks/')

我的 urls.py

...
(r'^reMap/$', reMapWizard([reMapStart, reMapLocationConfirmation, reMapData])),
...

第一次提交后由 Django 为随机位置生成的 html 代码

<form action='.' method='POST'><div style='display:none'>
<input type='hidden' name='csrfmiddlewaretoken' value='0f61c17790aa7ecc782dbfe7438031a8' /></div>
<table>
    <input type="hidden" name="wizard_step" value="1" />
    <input type="hidden" name="0-location" value="market street san francisco" id="id_0-location" /><input type="hidden" name="0-technology" value="car" id="id_0-technology" /><input type="hidden" name="hash_0" value="8a654e29d73f2c2f6660b5beb182f0c8" />
    <tr><th><label for="id_1-locations_0">Locations:</label></th><td><ul class="errorlist"><li>Select a valid choice. Market St, San Francisco, CA, USA is not one of the available choices.</li></ul><ul>

<li><label for="id_1-locations_0"><input checked="checked" type="radio" id="id_1-locations_0" value="Market St, San Francisco, CA, USA" name="1-locations" /> Market St, San Francisco, CA, USA</label></li>
</ul></td></tr>
</table>
<p><input type="submit" value="Submit" /></p>
</form>

【问题讨论】：

标签： django django-formwizard

【解决方案1】：

尝试为您的所有位置设置默认选项或不要将其设为ChoiceField，而是设为CharField，并且仅在您覆盖表单的地方将其设置为ChoiceField。

locations = forms.ChoiceField(widget=RadioSelect(), choices = [..all..])

我猜这些选择不会在多个POSTs 中持续存在，并且向导会在最后验证所有表单。

即使您的表单在该步骤中有效，它最终也会变得无效。

因此，将所有位置添加到原始字段构造函数或将其设为 CharField 以删除选择的自动验证。

【讨论】：

【解决方案2】：

在宇治的帮助下解决办法：

用 CharField 初始化类

class reMapLocationConfirmation(forms.Form):
   locations = forms.CharField()

然后覆盖到选择字段

class reMapWizard(FormWizard):

    def render_template(self, request, form, previous_fields, step, context=None):
        if step == 1:
            location = request.POST.get('0-location')
            address, lat, lng, country = getLocation(location)
            form.fields['locations'] = forms.ChoiceField(widget=RadioSelect(), choices = [])
            form.fields['locations'].choices = [(x, x) for x in address]
        return super(reMapWizard, self).render_template(request, form, previous_fields, step, context)

【讨论】：