django的模板标签语言

目录

1.变量   {{   }}

2.标签   {% %}

（1）{% if %}

（2）{% ifequal %}

（3）{% for %}

在这讲一下{{forloop}}变量：

3.过滤器  filter  {{   |   }}

---

django拥有一套完整的模板系统

1.变量   {{   }}

（1）传入前端的变量最外层一定是一个字典

（2）具体的变量可以是字符串，列表，字典类型

（3）变量通过.方法可以调用自己的无参数方法，索引

（4）如果变量是字典，也可以通过键调用值

views.py

from django.http import HttpResponse
from django.template import Template,Context
def variable(request):
    template=Template(
        """
            <p>变量常规用法：{{variable}}</p>
            <p>变量常规用法_变量列表:{{variable1}}</p>
            <p>变量常规用法_变量索引:{{variable1.1}}</p>
            <p>变量常规用法_变量无参数方法:{{variable2.upper}}</p>
            <p>变量常规用法_变量字典:{{variable3}}</p>
            <p>变量常规用法_变量字典键值:{{variable3.name}}</p>
        """
    )
    data=Context({
        "variable":"张三",
        "variable1":[1,2,3,4],
        "variable2":"zhangsan",
        "variable3":{"name":"李四","gender":"男"},
    })
    result=template.render(data)
    return HttpResponse(result)

urls.py

服务器运行：

---

2.标签   {% %}

（1）{% if %}

判断指定条件true,false ,通常判断一个变量是否存在或者为真

{% if %}标签需要{% endif %}标签进行闭合

{% if %}可以有{% else %}

视图文件 views.py

from django.http import HttpResponse
from django.template import Template,Context
def label_if(request,name):
    """
    if标签
    """
    template=Template(
        """
            {% if username %}
                <p>欢迎登陆&nbsp;{{username}}</p>
            {% else %}
                <a href="#">请登录</a>
            {% endif %}
        """
    )
    data=Context({
        "username":name,
    })
    result=template.render(data)
    return HttpResponse(result)

路由文件 urls.py

---

（2）{% ifequal %}

判断两个量是否相等，通常用于比较

{% ifequal %}标签需要{% endifequal %}标签进行闭合

{% ifequal %}可以有{% else %}

视图文件 views.py

from django.http import HttpResponse
from django.template import Template, Context


def label_ifequal(request, name, gender):
    """
    ifequal标签
    """
    template = Template(
        """
            {% ifequal gender "M" %}
                <p>{{username}}先生，你好!</p>
            {% else %}
                <p>{{username}}女士,你好!</p>
            {% endifequal %}
        """
    )
    data = Context({
        "username": name,
        "gender": gender,
    })
    result = template.render(data)
    return HttpResponse(result)

路由文件 urls.py

re_path(r'label_ifequal/(?P<name>\w{1,4})/(?P<gender>[M,F])',label_ifequal),

---

（3）{% for %}

{% for %}标签需要{% endfor %}标签进行闭合

{% for %}标签采用了和python一样的for in结构

{% for %}循环出来的不是html对象，只是数据

视图文件 views.py

from django.http import HttpResponse
from django.template import Template,Context
def label_for(request):
    """
    for标签
    """
    template=Template(
        """
            <table>
            <th>标题</th>
            <th>作者</th>
            <th>类型</th>
            <th>封面</th>
            {% for article in articles %}
                <tr>
                    <td>{{article.title}}</td>
                    <td>{{article.author}}</td>
                    <td>{{article.type}}</td>
                    <td><img  style='width:100px;height:100px;' src='{{article.picture}}'></td>
            
                </tr>
            {% endfor %}
            </table>
        
        """
    )
    data=Context({
        "articles":[
            {
                "title": "背影",
                "author": "朱自清",
                "type": "散文",
                "picture": "https://ss0.bdstatic.com/94oJfD_bAAcT8t7mm9GUKT-xh_/timg?image&quality=100&size=b4000_4000&sec=1553755201&di=e10ae2618dce21703114e119402a522e&src=http://img3.duitang.com/uploads/item/201507/05/20150705135641_K4sVA.jpeg"

            },
            {"title": "诛仙", "author": "萧鼎", "type": "小说",
             "picture": "https://ss0.bdstatic.com/70cFvHSh_Q1YnxGkpoWK1HF6hhy/it/u=328549116,1379468112&fm=26&gp=0.jpg"},
            {"title": "西游记", "author": "吴承恩", "type": "小说",
             "picture": "https://ss2.bdstatic.com/70cFvnSh_Q1YnxGkpoWK1HF6hhy/it/u=4100856954,312579948&fm=26&gp=0.jpg"},
            {"title": "鲁宾逊漂流记", "author": "丹尼尔·笛福", "type": "小说",
             "picture": "https://timgsa.baidu.com/timg?image&quality=80&size=b9999_10000&sec=1553750785199&di=d906d54cf8456736d285b99f601bb968&imgtype=jpg&src=http%3A%2F%2Fimg4.imgtn.bdimg.com%2Fit%2Fu%3D1665326279%2C2802541090%26fm%3D214%26gp%3D0.jpg"},
            {"title": "活着", "author": "余华", "type": "小说",
             "picture": "https://timgsa.baidu.com/timg?image&quality=80&size=b9999_10000&sec=1553750868172&di=ccae9a343204f59cecbcc21c9e811e58&imgtype=0&src=http%3A%2F%2Fs1.sinaimg.cn%2Flarge%2F001Pe7mxzy76VARpXvdc3"},
        ]

    })
    result=template.render(data)
    return HttpResponse(result)

路由文件 urls.py

---

在这讲一下{{forloop}}变量：

forloop是django模板语言定义好的一个变量，用来表示循环当中的每次循环

forloop为嵌套循环提供了parentloop参数来记录当前玄幻的上一层循环的情况

通常我们使用forloop标签进行循环的口头或者末尾判断

视图文件 views.py

from django.http import HttpResponse
from django.template import Template,Context
def label_forloop(request):
    """
    forloop 变量
    """
    template=Template(
        """
            <h3>单层循环</h3>
            <ul>
                {% for i in range %}
                    <p>{{forloop}}</p>
                {% endfor %}
            
            </ul>
            <h3>嵌套循环</h3>
            <ul>
            {% for i in range %}
                {% for article in articles %}
                    <li>{{article}}是第{{forloop.counter}}次循环,它的父循环是第{{forloop.parentloop.counter}}次循环</li>
                {% endfor %}
                {% if not forloop.last %}
                    <p>=================================</p>
                {% endif %}
            {% endfor %}
            </ul>
        """

    )
    data=Context({
        "articles":["背影","西游记","水浒传","三国演义","活着"],
        "range":["a","b","c"],
    })
    result=template.render(data)
    return HttpResponse(result)

路由文件 urls.py

---

3.过滤器  filter  {{   |   }}

对变量进行具体功能的处理

safe:去掉前端的转义

upper:大写

视图文件 views.py

from django.http import HttpResponse
from django.template import Template, Context


def filter(request, str):
    template = Template(
        """
            {{argv|safe}}
            <br>
            {{str|upper}}
        """
    )
    data = Context({
        "argv": "<img style='width:100px;height；100px;' src='http://cdn.duitang.com/uploads/item/201507/15/20150715122359_WmwTv.jpeg'>",
        "str": str,
    })
    result = template.render(data)
    return HttpResponse(result)

路由文件 urls.py