forms組件

時間 2019-11-24

標籤 forms 組件简体版

原文原文鏈接

Form組件

服務端假設全部用戶提交的數據都是不可信任的，因此Django框架內置了form組件來驗證用戶提交的信息html

form組件的2大功能：

　　 1 驗證（顯示錯誤信息）
　　 2 保留用戶上次輸入的信息
3.能夠生成html標籤git

1 驗證（顯示錯誤信息）

示例/:註冊用戶字段校驗django

模型：models.py:app

class UserInfo(models.Model):
    name=models.CharField(max_length=32)
    pwd=models.CharField(max_length=32)
    email=models.EmailField()
    tel=models.CharField(max_length=32)

模板: register.html:框架

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>

</head>
<body>

<form action="" method="post">
    {% csrf_token %}
    <div>
        <label for="user">用戶名</label>
        <p><input type="text" name="name" id="name"></p>
    </div>
    <div>
        <label for="pwd">密碼</label>
        <p><input type="password" name="pwd" id="pwd"></p>
    </div>
    <div>
        <label for="r_pwd">確認密碼</label>
        <p><input type="password" name="r_pwd" id="r_pwd"></p>
    </div>
     <div>
        <label for="email">郵箱</label>
        <p><input type="text" name="email" id="email"></p>
    </div>
    <input type="submit">
</form>

</body>
</html>

View Code

視圖函數：register:ide

# forms組件
from django.forms import widgets

wid_01=widgets.TextInput(attrs={"class":"form-control"})
wid_02=widgets.PasswordInput(attrs={"class":"form-control"})

class UserForm(forms.Form):
    name=forms.CharField(max_length=32,
                         widget=wid_01
                         )
    pwd=forms.CharField(max_length=32,widget=wid_02)
    r_pwd=forms.CharField(max_length=32,widget=wid_02)
    email=forms.EmailField(widget=wid_01)
    tel=forms.CharField(max_length=32,widget=wid_01)



def register(request):

    if request.method=="POST":
        form=UserForm(request.POST)
        if form.is_valid():
            print(form.cleaned_data)       # 全部乾淨的字段以及對應的值
        else:
            print(form.cleaned_data)       #
            print(form.errors)             # ErrorDict : {"校驗錯誤的字段":["錯誤信息",]}
            print(form.errors.get("name")) # ErrorList ["錯誤信息",]
        return HttpResponse("OK")
    form=UserForm()
    return render(request,"register.html",locals())

View Code

其中視圖函數中關於Widgets的詳細使用,可參考:http://www.liujiangblog.com/course/django/155函數

2. -- 能夠生成html標籤

生成HTML 標籤有三種渲染方式post

1. 渲染成文字段落as_p()

Form.as_p()ui

該方法將form渲染成一系列<p>標籤，每一個<p>標籤包含一個字段；spa

<form action="" method="post">
    {% csrf_token %}
    
    {{ form.as_p }}
    <input type="submit" class="btn btn-default pull-right">

</form>

2.渲染方式二循環form表單,利用字段:

rm action="" method="post">
    {% csrf_token %}
    {% for field in form %}
        <div>
            <label for="">{{ field.label }}</label>
            {{ field }}
        </div>
    {% endfor %}
    <input type="submit" class="btn btn-default pull-right">
</form>

3.渲染方式三:

<form action="" method="post">
        {% csrf_token %}
        <div>
            <label for="">用戶名</label>
            {{ form.name }}
        </div>
        <div>
            <label for="">密碼</label>
            {{ form.pwd }}
        </div>
        <div>
            <label for="">確認密碼</label>
            {{ form.r_pwd }}
        </div>
        <div>
            <label for=""> 郵箱</label>
            {{ form.email }}
        </div>

        <input type="submit" class="btn btn-default pull-right">
</form>

View Code

3.返回並在界面表示錯誤

HTML示例:

<form action="" method="post" novalidate>
    {% csrf_token %}
    
    {% for field in form %}
        <div>
            <label for="">{{ field.label }}</label>
            {{ field }} <span class="pull-right" style="color: red">{{ field.errors.0 }}</span>
        </div>
    {% endfor %}
    <input type="submit" class="btn btn-default">

</form>

增長全局鉤子和局部鉤子的代碼示例:

views:

from django.shortcuts import render,HttpResponse
from django import forms
# Create your views here.
from django.forms import widgets
from django.core.exceptions import ValidationError

wid_01=widgets.TextInput(attrs={"class":"form-control"})
wid_02=widgets.PasswordInput(attrs={"class":"form-control"})

class UserForm(forms.Form):
    name=forms.CharField(max_length=32,
                         widget=wid_01
                         )
    pwd=forms.CharField(max_length=32,widget=wid_02)
    r_pwd=forms.CharField(max_length=32,widget=wid_02)
    email=forms.EmailField(widget=wid_01)
    tel=forms.CharField(max_length=32,widget=wid_01)

    # 局部鉤子
    def clean_name(self):
        val = self.cleaned_data.get("name")
        if not val.isdigit():
            return val
        else:
            raise ValidationError("用戶名不能是純數字!")

    # 全局鉤子

    def clean(self):
        pwd = self.cleaned_data.get("pwd")
        r_pwd = self.cleaned_data.get("r_pwd")

        if pwd == r_pwd:
            return self.cleaned_data
        else:
            raise ValidationError('兩次密碼不一致!')



def register(request):

    if request.method=="POST":
        form=UserForm(request.POST)
        if form.is_valid():
            print(form.cleaned_data)       # 全部乾淨的字段以及對應的值
        else:
            clean_error = form.errors.get("__all__")
            print(form.cleaned_data)       #
            print(form.errors)             # ErrorDict : {"校驗錯誤的字段":["錯誤信息",]}
            print(form.errors.get("name")) # ErrorList ["錯誤信息",]
            return render(request, "register.html", locals())
        return HttpResponse("OK")
    form=UserForm()
    return render(request,"register.html",locals())

View Code

html:

<form action="" method="post" novalidate>
        {% csrf_token %}
        {% for field in form %}
            <div>
                <label for="">{{ field.label }}</label>
                {{ field }}
                <span class="pull-right" style="color: red">
                      {% if field.label == 'R pwd' %}
                      <span>{{ clean_error.0 }}</span>
                      {% endif %}
                      {{ field.errors.0 }}
                </span>
            </div>
        {% endfor %}
        <input type="submit" class="btn btn-default">

</form>

View Code

如下幾種form表單渲染方式示例,請詳看:

# 經過直接form生成的HTML文件以下
# <form action="/name/" method="post">
#     {% csrf_token %}
#     {{ form }}
#     <input type="submit" value="Submit" />
# </form>

# 渲染後:
# <form action="/name/" method="post">
#     <input type="hidden" name="csrfmiddlewaretoken" value="B3iGL11TlxDRrhRhC96iDdQrJSOiUDoU8QYgw1euE2sddZONoAogOnfHJZtgSY0X">
#     <label for="id_subject">Subject:</label><input type="text" name="subject" maxlength="100" required="" id="id_subject">
#     <label for="id_message">Message:</label><textarea name="message" cols="40" rows="10" required="" id="id_message"></textarea>
#     <label for="id_sender">Sender:</label><input type="email" name="sender" required="" id="id_sender">
#     <label for="id_cc_myself">Cc myself:</label><input type="checkbox" name="cc_myself" id="id_cc_myself">
#     <input type="submit" value="Submit">
# </form>


# 經過直接form.as_p生成的HTML文件以下
# <form action="/name/" method="post">
#     {% csrf_token %}
#     {{ form.as_p }}
#     <input type="submit" value="Submit" />
# </form>

# 渲染後:
# <form action="/name/" method="post">
#     <input type="hidden" name="csrfmiddlewaretoken" value="bT7RLCRW7B40rLZye7rtQ9n2Nr0tvcfVIGNrwC4xq6TmdtW40yJr1jMiNyFrtxRY">
#     <p><label for="id_subject">Subject:</label> <input type="text" name="subject" maxlength="100" required="" id="id_subject"></p>
#     <p><label for="id_message">Message:</label> <textarea name="message" cols="40" rows="10" required="" id="id_message"></textarea></p>
#     <p><label for="id_sender">Sender:</label> <input type="email" name="sender" required="" id="id_sender"></p>
#     <p><label for="id_cc_myself">Cc myself:</label> <input type="checkbox" name="cc_myself" id="id_cc_myself"></p>
#     <input type="submit" value="Submit">
# </form>


# 直接{{ form }}雖然好，啥都不用操心，可是每每並非你想要的，好比你要使用CSS和JS，好比你要引入Bootstarps框架，這些都須要對錶單內的input元素進行額外控制，那怎麼辦呢？手動渲染字段就能夠了。
# 能夠經過{{ form.name_of_field }}獲取每個字段，而後分別渲染，以下例所示：

# {{ form.non_field_errors }}
# <div class="fieldWrapper">
#     {{ form.subject.errors }}
#     <label for="{{ form.subject.id_for_label }}">Email subject:</label>
#     {{ form.subject }}
# </div>
# <div class="fieldWrapper">
#     {{ form.message.errors }}
#     <label for="{{ form.message.id_for_label }}">Your message:</label>
#     {{ form.message }}
# </div>
# <div class="fieldWrapper">
#     {{ form.sender.errors }}
#     <label for="{{ form.sender.id_for_label }}">Your email address:</label>
#     {{ form.sender }}
# </div>
# <div class="fieldWrapper">
#     {{ form.cc_myself.errors }}
#     <label for="{{ form.cc_myself.id_for_label }}">CC yourself?</label>
#     {{ form.cc_myself }}
# </div>


# 渲染後:
# < div class ="fieldWrapper" >
#     < label for ="id_subject" > Email subject:</label>
#     < input type = "text" name = "subject" maxlength = "100" required = "" id = "id_subject" >
# </div >
#
# < div class ="fieldWrapper" >
#     < labelfor ="id_message" > Your message:< / label >
#     < textarea name = "message" cols = "40" rows = "10" required = "" id = "id_message" > < / textarea >
# </div>
#
# < div class ="fieldWrapper" >
#     < label for ="id_sender" > Your email address:< / label >
#     < input type = "email" name = "sender" required = "" id = "id_sender" >
# </div >
#
# <div class ="fieldWrapper" >
#     <label for ="id_cc_myself" > CC yourself? < / label >
#     <input type = "checkbox" name = "cc_myself" id = "id_cc_myself" >
# </div>


# 4. 循環表單的字段：
# 若是你的表單字段有相同格式的HMTL表現，那麼徹底能夠循環生成，沒必要要手動的編寫每一個字段，減小冗餘和重複代碼，只須要使用模板語言中的{% for %}循環，以下所示：
# {% for field in form %}
#     <div class="fieldWrapper">
#         {{ field.errors }}
#         {{ field.label_tag }} {{ field }}
#         {% if field.help_text %}
#         <p class="help">{{ field.help_text|safe }}</p>
#         {% endif %}
#     </div>
# {% endfor %}

View Code

{{ field }}中很是有用的屬性，這些都是Django內置的模板語言給咱們提供的方便：

屬性    說明
{{ field.label }}    字段對應的label信息
{{ field.label_tag }}    自動生成字段的label標籤，注意與{{ field.label }}的區別。
{{ field.id_for_label }}    自定義字段標籤的id
{{ field.value }}    當前字段的值，好比一個Email字段的值someone@example.com
{{ field.html_name }}    指定字段生成的input標籤中name屬性的值
{{ field.help_text }}    字段的幫助信息
{{ field.errors }}    包含錯誤信息的元素
{{ field.is_hidden }}    用於判斷當前字段是否爲隱藏的字段，若是是，返回True
{{ field.field }}    返回字段的參數列表。例如{{ char_field.field.max_length }}

View Code

詳細可參考:http://www.javashuo.com/article/p-gxmmeyef-e.html 或

劉江博客:http://www.liujiangblog.com/course/django/153

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