Django之Form组件
https://www.cnblogs.com/wupeiqi/articles/6144178.html
Django的Form主要具有一下几大功能:
- 生成HTML标签
- 验证用户数据(显示错误信息)
- HTML Form提交保留上次提交数据
- 初始化页面显示内容
小试牛刀
1、创建Form类
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from django.forms import Form from django.forms import widgets from django.forms import fields class MyForm(Form): user = fields.CharField( widget = widgets.TextInput(attrs = { 'id' : 'i1' , 'class' : 'c1' }) ) gender = fields.ChoiceField( choices = (( 1 , '男' ), ( 2 , '女' ),), initial = 2 , widget = widgets.RadioSelect ) city = fields.CharField( initial = 2 , widget = widgets.Select(choices = (( 1 , '上海' ),( 2 , '北京' ),)) ) pwd = fields.CharField( widget = widgets.PasswordInput(attrs = { 'class' : 'c1' }, render_value = True ) ) |
2、View函数处理
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from django.shortcuts import render, redirect from .forms import MyForm def index(request): if request.method = = "GET" : obj = MyForm() return render(request, 'index.html' , { 'form' : obj}) elif request.method = = "POST" : obj = MyForm(request.POST, request.FILES) if obj.is_valid(): values = obj.clean() print (values) else : errors = obj.errors print (errors) return render(request, 'index.html' , { 'form' : obj}) else : return redirect( 'http://www.google.com' ) |
3、生成HTML
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<form action = "/" method = "POST" enctype = "multipart/form-data" > <p>{{ form.user }} {{ form.user.errors }}< / p> <p>{{ form.gender }} {{ form.gender.errors }}< / p> <p>{{ form.city }} {{ form.city.errors }}< / p> <p>{{ form.pwd }} {{ form.pwd.errors }}< / p> < input type = "submit" / > < / form> |
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<form method="POST" enctype="multipart/form-data"> {% csrf_token %} {{ form.xxoo.label }} {{ form.xxoo.id_for_label }} {{ form.xxoo.label_tag }} {{ form.xxoo.errors }} <p>{{ form.user }} {{ form.user.errors }}</p> <input type="submit" /> </form>
Form类
创建Form类时,主要涉及到 【字段】 和 【插件】,字段用于对用户请求数据的验证,插件用于自动生成HTML;
1、Django内置字段如下:
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Field required = True , 是否允许为空 widget = None , HTML插件 label = None , 用于生成Label标签或显示内容 initial = None , 初始值 help_text = '', 帮助信息(在标签旁边显示) error_messages = None , 错误信息 { 'required' : '不能为空' , 'invalid' : '格式错误' } show_hidden_initial = False , 是否在当前插件后面再加一个隐藏的且具有默认值的插件(可用于检验两次输入是否一直) validators = [], 自定义验证规则 localize = False , 是否支持本地化 disabled = False , 是否可以编辑 label_suffix = None Label内容后缀 CharField(Field) max_length = None , 最大长度 min_length = None , 最小长度 strip = True 是否移除用户输入空白 IntegerField(Field) max_value = None , 最大值 min_value = None , 最小值 FloatField(IntegerField) ... DecimalField(IntegerField) max_value = None , 最大值 min_value = None , 最小值 max_digits = None , 总长度 decimal_places = None , 小数位长度 BaseTemporalField(Field) input_formats = None 时间格式化 DateField(BaseTemporalField) 格式: 2015 - 09 - 01 TimeField(BaseTemporalField) 格式: 11 : 12 DateTimeField(BaseTemporalField)格式: 2015 - 09 - 01 11 : 12 DurationField(Field) 时间间隔: % d % H: % M: % S. % f ... RegexField(CharField) regex, 自定制正则表达式 max_length = None , 最大长度 min_length = None , 最小长度 error_message = None , 忽略,错误信息使用 error_messages = { 'invalid' : '...' } EmailField(CharField) ... FileField(Field) allow_empty_file = False 是否允许空文件 ImageField(FileField) ... 注:需要PIL模块,pip3 install Pillow 以上两个字典使用时,需要注意两点: - form表单中 enctype = "multipart/form-data" - view函数中 obj = MyForm(request.POST, request.FILES) URLField(Field) ... BooleanField(Field) ... NullBooleanField(BooleanField) ... ChoiceField(Field) ... choices = (), 选项,如:choices = (( 0 , '上海' ),( 1 , '北京' ),) required = True , 是否必填 widget = None , 插件,默认select插件 label = None , Label内容 initial = None , 初始值 help_text = '', 帮助提示 ModelChoiceField(ChoiceField) ... django.forms.models.ModelChoiceField queryset, # 查询数据库中的数据 empty_label = "---------" , # 默认空显示内容 to_field_name = None , # HTML中value的值对应的字段 limit_choices_to = None # ModelForm中对queryset二次筛选 ModelMultipleChoiceField(ModelChoiceField) ... django.forms.models.ModelMultipleChoiceField TypedChoiceField(ChoiceField) coerce = lambda val: val 对选中的值进行一次转换 empty_value = '' 空值的默认值 MultipleChoiceField(ChoiceField) ... TypedMultipleChoiceField(MultipleChoiceField) coerce = lambda val: val 对选中的每一个值进行一次转换 empty_value = '' 空值的默认值 ComboField(Field) fields = () 使用多个验证,如下:即验证最大长度 20 ,又验证邮箱格式 fields.ComboField(fields = [fields.CharField(max_length = 20 ), fields.EmailField(),]) MultiValueField(Field) PS: 抽象类,子类中可以实现聚合多个字典去匹配一个值,要配合MultiWidget使用 SplitDateTimeField(MultiValueField) input_date_formats = None , 格式列表:[ '%Y--%m--%d' , '%m%d/%Y' , '%m/%d/%y' ] input_time_formats = None 格式列表:[ '%H:%M:%S' , '%H:%M:%S.%f' , '%H:%M' ] FilePathField(ChoiceField) 文件选项,目录下文件显示在页面中 path, 文件夹路径 match = None , 正则匹配 recursive = False , 递归下面的文件夹 allow_files = True , 允许文件 allow_folders = False , 允许文件夹 required = True , widget = None , label = None , initial = None , help_text = '' GenericIPAddressField protocol = 'both' , both,ipv4,ipv6支持的IP格式 unpack_ipv4 = False 解析ipv4地址,如果是::ffff: 192.0 . 2.1 时候,可解析为 192.0 . 2.1 , PS:protocol必须为both才能启用 SlugField(CharField) 数字,字母,下划线,减号(连字符) ... UUIDField(CharField) uuid类型 ... |
注:UUID是根据MAC以及当前时间等创建的不重复的随机字符串
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>>> import uuid # make a UUID based on the host ID and current time >>> uuid.uuid1() # doctest: +SKIP UUID('a8098c1a-f86e-11da-bd1a-00112444be1e') # make a UUID using an MD5 hash of a namespace UUID and a name >>> uuid.uuid3(uuid.NAMESPACE_DNS, 'python.org') UUID('6fa459ea-ee8a-3ca4-894e-db77e160355e') # make a random UUID >>> uuid.uuid4() # doctest: +SKIP UUID('16fd2706-8baf-433b-82eb-8c7fada847da') # make a UUID using a SHA-1 hash of a namespace UUID and a name >>> uuid.uuid5(uuid.NAMESPACE_DNS, 'python.org') UUID('886313e1-3b8a-5372-9b90-0c9aee199e5d') # make a UUID from a string of hex digits (braces and hyphens ignored) >>> x = uuid.UUID('{00010203-0405-0607-0809-0a0b0c0d0e0f}') # convert a UUID to a string of hex digits in standard form >>> str(x) '00010203-0405-0607-0809-0a0b0c0d0e0f' # get the raw 16 bytes of the UUID >>> x.bytes b'\x00\x01\x02\x03\x04\x05\x06\x07\x08\t\n\x0b\x0c\r\x0e\x0f' # make a UUID from a 16-byte string >>> uuid.UUID(bytes=x.bytes) UUID('00010203-0405-0607-0809-0a0b0c0d0e0f')
2、Django内置插件:
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TextInput( Input ) NumberInput(TextInput) EmailInput(TextInput) URLInput(TextInput) PasswordInput(TextInput) HiddenInput(TextInput) Textarea(Widget) DateInput(DateTimeBaseInput) DateTimeInput(DateTimeBaseInput) TimeInput(DateTimeBaseInput) CheckboxInput Select NullBooleanSelect SelectMultiple RadioSelect CheckboxSelectMultiple FileInput ClearableFileInput MultipleHiddenInput SplitDateTimeWidget SplitHiddenDateTimeWidget SelectDateWidget |
常用选择插件
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# 单radio,值为字符串 # user = fields.CharField( # initial=2, # widget=widgets.RadioSelect(choices=((1,'上海'),(2,'北京'),)) # ) # 单radio,值为字符串 # user = fields.ChoiceField( # choices=((1, '上海'), (2, '北京'),), # initial=2, # widget=widgets.RadioSelect # ) # 单select,值为字符串 # user = fields.CharField( # initial=2, # widget=widgets.Select(choices=((1,'上海'),(2,'北京'),)) # ) # 单select,值为字符串 # user = fields.ChoiceField( # choices=((1, '上海'), (2, '北京'),), # initial=2, # widget=widgets.Select # ) # 多选select,值为列表 # user = fields.MultipleChoiceField( # choices=((1,'上海'),(2,'北京'),), # initial=[1,], # widget=widgets.SelectMultiple # ) # 单checkbox # user = fields.CharField( # widget=widgets.CheckboxInput() # ) # 多选checkbox,值为列表 # user = fields.MultipleChoiceField( # initial=[2, ], # choices=((1, '上海'), (2, '北京'),), # widget=widgets.CheckboxSelectMultiple # ) |
在使用选择标签时,需要注意choices的选项可以从数据库中获取,但是由于是静态字段 ***获取的值无法实时更新***,那么需要自定义构造方法从而达到此目的。
方式一:
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from django.forms import Form from django.forms import widgets from django.forms import fields from django.core.validators import RegexValidator class MyForm(Form): user = fields.ChoiceField( # choices=((1, '上海'), (2, '北京'),), initial = 2 , widget = widgets.Select ) def __init__( self , * args, * * kwargs): super (MyForm, self ).__init__( * args, * * kwargs) # self.fields['user'].widget.choices = ((1, '上海'), (2, '北京'),) # 或 self .fields[ 'user' ].widget.choices = models.Classes.objects. all ().value_list( 'id' , 'caption' ) |
方式二:
使用django提供的ModelChoiceField和ModelMultipleChoiceField字段来实现
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from django import forms from django.forms import fields from django.forms import widgets from django.forms import models as form_model from django.core.exceptions import ValidationError from django.core.validators import RegexValidator class FInfo(forms.Form): authors = form_model.ModelMultipleChoiceField(queryset = models.NNewType.objects. all ()) # authors = form_model.ModelChoiceField(queryset=models.NNewType.objects.all()) |
自定义验证规则
方式一:
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from django.forms import Form from django.forms import widgets from django.forms import fields from django.core.validators import RegexValidator class MyForm(Form): user = fields.CharField( validators = [RegexValidator(r '^[0-9]+$' , '请输入数字' ), RegexValidator(r '^159[0-9]+$' , '数字必须以159开头' )], ) |
方式二:
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import re from django.forms import Form from django.forms import widgets from django.forms import fields from django.core.exceptions import ValidationError # 自定义验证规则 def mobile_validate(value): mobile_re = re. compile (r '^(13[0-9]|15[012356789]|17[678]|18[0-9]|14[57])[0-9]{8}$' ) if not mobile_re.match(value): raise ValidationError( '手机号码格式错误' ) class PublishForm(Form): title = fields.CharField(max_length = 20 , min_length = 5 , error_messages = { 'required' : '标题不能为空' , 'min_length' : '标题最少为5个字符' , 'max_length' : '标题最多为20个字符' }, widget = widgets.TextInput(attrs = { 'class' : "form-control" , 'placeholder' : '标题5-20个字符' })) # 使用自定义验证规则 phone = fields.CharField(validators = [mobile_validate, ], error_messages = { 'required' : '手机不能为空' }, widget = widgets.TextInput(attrs = { 'class' : "form-control" , 'placeholder' : u '手机号码' })) email = fields.EmailField(required = False , error_messages = { 'required' : u '邮箱不能为空' , 'invalid' : u '邮箱格式错误' }, widget = widgets.TextInput(attrs = { 'class' : "form-control" , 'placeholder' : u '邮箱' })) |
方法三:自定义方法
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from django import forms from django.forms import fields from django.forms import widgets from django.core.exceptions import ValidationError from django.core.validators import RegexValidator class FInfo(forms.Form): username = fields.CharField(max_length = 5 , validators = [RegexValidator(r '^[0-9]+$' , 'Enter a valid extension.' , 'invalid' )], ) email = fields.EmailField() def clean_username( self ): """ Form中字段中定义的格式匹配完之后,执行此方法进行验证 :return: """ value = self .cleaned_data[ 'username' ] if "666" in value: raise ValidationError( '666已经被玩烂了...' , 'invalid' ) return value |
方式四:同时生成多个标签进行验证
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from django.forms import Form from django.forms import widgets from django.forms import fields from django.core.validators import RegexValidator ############## 自定义字段 ############## class PhoneField(fields.MultiValueField): def __init__( self , * args, * * kwargs): # Define one message for all fields. error_messages = { 'incomplete' : 'Enter a country calling code and a phone number.' , } # Or define a different message for each field. f = ( fields.CharField( error_messages = { 'incomplete' : 'Enter a country calling code.' }, validators = [ RegexValidator(r '^[0-9]+$' , 'Enter a valid country calling code.' ), ], ), fields.CharField( error_messages = { 'incomplete' : 'Enter a phone number.' }, validators = [RegexValidator(r '^[0-9]+$' , 'Enter a valid phone number.' )], ), fields.CharField( validators = [RegexValidator(r '^[0-9]+$' , 'Enter a valid extension.' )], required = False , ), ) super (PhoneField, self ).__init__(error_messages = error_messages, fields = f, require_all_fields = False , * args, * * kwargs) def compress( self , data_list): """ 当用户验证都通过后,该值返回给用户 :param data_list: :return: """ return data_list ############## 自定义插件 ############## class SplitPhoneWidget(widgets.MultiWidget): def __init__( self ): ws = ( widgets.TextInput(), widgets.TextInput(), widgets.TextInput(), ) super (SplitPhoneWidget, self ).__init__(ws) def decompress( self , value): """ 处理初始值,当初始值initial不是列表时,调用该方法 :param value: :return: """ if value: return value.split( ',' ) return [ None , None , None ] |
初始化数据
在Web应用程序中开发编写功能时,时常用到获取数据库中的数据并将值初始化在HTML中的标签上。
1、Form
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from django.forms import Form from django.forms import widgets from django.forms import fields from django.core.validators import RegexValidator class MyForm(Form): user = fields.CharField() city = fields.ChoiceField( choices = (( 1 , '上海' ), ( 2 , '北京' ),), widget = widgets.Select ) |
2、Views
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from django.shortcuts import render, redirect from .forms import MyForm def index(request): if request.method = = "GET" : values = { 'user' : 'root' , 'city' : 2 } obj = MyForm(values) return render(request, 'index.html' , { 'form' : obj}) elif request.method = = "POST" : return redirect( 'http://www.google.com' ) else : return redirect( 'http://www.google.com' ) |
3、HTML