python---django中form组件自定制属性以及表单的各种验证

Posted 2020-10-29 山上有风景

分析widget：

class TestForm(forms.Form):
    user = fields.CharField(
            required = True,
            widget = widgets.TextInput()
    )

追踪widgets.py

__all__ = (
    ‘Media‘, ‘MediaDefiningClass‘, ‘Widget‘, ‘TextInput‘, ‘NumberInput‘,
    ‘EmailInput‘, ‘URLInput‘, ‘PasswordInput‘, ‘HiddenInput‘,
    ‘MultipleHiddenInput‘, ‘FileInput‘, ‘ClearableFileInput‘, ‘Textarea‘,
    ‘DateInput‘, ‘DateTimeInput‘, ‘TimeInput‘, ‘CheckboxInput‘, ‘Select‘,
    ‘NullBooleanSelect‘, ‘SelectMultiple‘, ‘RadioSelect‘,
    ‘CheckboxSelectMultiple‘, ‘MultiWidget‘, ‘SplitDateTimeWidget‘,
    ‘SplitHiddenDateTimeWidget‘, ‘SelectDateWidget‘,
)

全部控件

class TextInput(Input):
    input_type = ‘text‘
    template_name = ‘django/forms/widgets/text.html‘  #模板html存放路径

追踪父类：

class Input(Widget):
    """
    Base class for all <input> widgets.
    """
    input_type = None  # Subclasses must define this.
    template_name = ‘django/forms/widgets/input.html‘

    def __init__(self, attrs=None):  #发现这里又参数attrs可以设置属性
        if attrs is not None:
            attrs = attrs.copy()
            self.input_type = attrs.pop(‘type‘, self.input_type)
        super(Input, self).__init__(attrs)

    def get_context(self, name, value, attrs):
        context = super(Input, self).get_context(name, value, attrs)
        context[‘widget‘][‘type‘] = self.input_type
        return context

发现模板文件template_name = ‘django/forms/widgets/input.html‘，实际上并不存在，是调用了父类方法

class Widget(six.with_metaclass(RenameWidgetMethods)):
    def get_context(self, name, value, attrs):
        context = {}
        context[‘widget‘] = {
            ‘name‘: name,
            ‘is_hidden‘: self.is_hidden,
            ‘required‘: self.is_required,
            ‘value‘: self.format_value(value),
            ‘attrs‘: self.build_attrs(self.attrs, attrs),
            ‘template_name‘: self.template_name,
        }
        return context

    def render(self, name, value, attrs=None, renderer=None):
        """
        Returns this Widget rendered as HTML, as a Unicode string.  #生成对于html代码，返回使用
        """
        context = self.get_context(name, value, attrs)
        return self._render(self.template_name, context, renderer)

    def _render(self, template_name, context, renderer=None):
        if renderer is None:
            renderer = get_default_renderer()
        return mark_safe(renderer.render(template_name, context))

所以我们可以自定制样式，属性

widget = widgets.TextInput(attrs={"class":"c1"}),#这个属性，在前端进行设置就可以生成想要的样式

补充：在服务端生成原生字符串，不需要前端渲染时进行转义

txt = "<input type=‘text‘ />"  #默认发送到模板页面是无法显示需要进行处理

#在views中处理：
fromdjango.utils.safestring import make_safe
txt = mark_safe(txt)
#前端可以正常显示

 

select单选框：

sel_inp=fields.ChoiceField(
    choices = [(1,‘a‘),(2,‘b‘),]
)

select框：

sel_inp = fields.CharField(
        widget = widgets.Select(choices=[(1，‘a‘),(2,‘b‘),]）
)

combo多选：

radio_inp=fields.MultipleChoiceField(
    choices = [(1,‘a‘),(2,‘b‘),]   #含有multiple时可以写在外，也可以写在内，这里推荐在外
    widget = widgets.SelectMultiple(attrs={‘class‘:"c1"})
)

单选CheckBox：

    chk_inp = fields.CharField(
        widget = widgets.CheckboxInput()
    )

多选CheckBox

    mchk_inp = fields.MultipleChoiceField(
        widget = widgets.CheckboxSelectMultiple(),
        choices=[(1, "d"), (2, "e"),(3,‘r‘) ],
        initial = [2,3]
    )

radio单选：

    rad_inp = fields.ChoiceField(
        choices=[(1,"男"),(2,"女"),],
        initial=2,
        widget =widgets.RadioSelect(),
    )

 字段用于保存正则表达式，Html插件用于生产HTML标签（input）