模板选取字典最后一个值

要使用自定义过滤器
模板自带的make_list过滤器没什么用，它只会把所有传入的参数转成字符串再一个一个的切片['s','t','r']
myapp_extras.py

  1. from django import template
  3. register = template.Library()
  5. @register.filter
  6. def getlastkv(value):
  7.     lastkey = list(value)[-1]
  8.     lastvalue = value[lastkey]
  9.     v = lastkey+'：'+lastvalue
  10.     return v

mytemplate.html

  1. {% for item in apply_all %}
  2.   {{item.procedure|getlastkv}}
  3. {% endfor %}

models.py

  1. class Apply(models.Model):
  2.     procedure = models.JSONField()

自定义表单form的错误信息error_message

从模型生成的表单

  1. class SupplierForm(ModelForm):
  2.     class Meta:
  3.         model = Supplier
  4.         fields = '__all__'
  5.         error_messages = {
  6.             'fieldname':{'unique':'该字段禁止重复！'},
  7.         }

后台获取多选select的值

  1. <select name="material" class="js-example-basic-multiple" multiple="multiple">
  2.   {% for obj in tags %}
  3.   <option value="{{ obj.pk }}">{{obj}}</option>
  4.   {% endfor %}
  5. </select>

views.py

  1. mt = self.request.GET.getlist("material")

获取模型字段所有的属性(fields)名称/值

只需要获取model的全部fields名字

views.py

  1. from .models import Bargain # 导入模型(model)
  2. field_list = [f.verbose_name for f in Bargain._meta.fields]

获取字段变量名用f.name

需要获取model下每个实例对应field的值

models.py

  1. TYPE_CHOICES = [
  2. ('0','工艺设备'),
  3. ('1','电气仪控'),
  4. ('2','其他'),
  5. ]
  7. class Bargain(models.Model):
  8.     itemType = models.CharField(
  9.         verbose_name='设备类型',
  10.         max_length=1,
  11.         choices=TYPE_CHOICES,
  12.         default='0',blank=True,null=True
  13.     )
  14.     def get_fields_value_dict(self):
  15.         return {field.verbose_name:field.value_from_object(self) 
  16.                 if field.value_from_object(self) else '' 
  17.                 for field in self.__class__._meta.fields}

需要注意构建的这个方法只会记录字段的值，这里返回的字典是{'设备类型':'0'}，要显示工艺设备，目前好像只能在获取字典后再修改，dict['设备类型'] = bargain.get_itemType_display()。目前field只有value_from_object可以返回值。

表单验证错误时修改widget的attr

forms.py

  1. from django.forms import ModelForm
  2. from .models import Sample
  3. class SampleForm(ModelForm):
  4.   class Meta:
  5.     model = Sample
  6.     fields = '__all__'
  7.     widgets = {'address': TextInput(attrs={'class': 'form-control', 'placeholder': "地址"})}
  8.   # 重写__init__来修改attr
  9.   def __init__(self, *args, **kwargs):
  10.     if self.errors:
  11.       err_keys = list(self.errors.keys())
  12.       for k in err_keys:
  13.           self.fields[k].widget.attrs.update({'class':"form-control is-invalid"})