69django之Form组件
Posted 布吉岛丶
tags:
篇首语:本文由小常识网(cha138.com)小编为大家整理,主要介绍了69django之Form组件相关的知识,希望对你有一定的参考价值。
本篇导航:
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
1、创建Form类
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
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
<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>
<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>
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:
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
>>> 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:
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
# 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:
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
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())
方式一:
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:
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}$\') if not mobile_re.match(value): raise ValidationError(\'手机号码格式错误\') class PublishForm(Form): title = fields.CharField(max_length=20, min_length=5, error_messages={\'required\': \'标题不能为空\', \'min_length\': \'标题最少为5个字符\', \'max_length\': \'标题最多为20个字符\'}, widget=widgets.TextInput(attrs={\'class\': "form-control", \'placeholder\': \'标题5-20个字符\'})) # 使用自定义验证规则 phone = fields.CharField(validators=[mobile_validate, ], error_messages={\'required\': \'手机不能为空\'}, widget=widgets.TextInput(attrs={\'class\': "form-control", \'placeholder\': u\'手机号码\'})) email = fields.EmailField(required=False, error_messages={\'required\': u\'邮箱不能为空\',\'invalid\': u\'邮箱格式错误\'}, widget=widgets.TextInput(attrs={\'class\': "form-control", \'placeholder\': u\'邮箱\'}))
方法三:自定义方法
from django import forms from django.forms import fields from django.forms import widgets from django.core.exceptions import ValidationError from django.core.validators import RegexValidator class FInfo(forms.Form): username = fields.CharField(max_length=5, validators=[RegexValidator(r\'^[0-9]+$\', \'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
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]
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
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
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
<form method="POST" enctype="multipart/form-data"> {% csrf_token %} <p>{{ form.user }} {{ form.user.errors }}</p> <p>{{ form.city }} {{ form.city.errors }}</p> <input type="submit"/> </form>
以上是关于69django之Form组件的主要内容,如果未能解决你的问题,请参考以下文章
69-django-forms组件源码刨析cookie与session