django 的模板语言

1、模版的执行

模版的创建过程，对于模版，其实就是读取模版（其中嵌套着模版标签），然后将 Model 中获取的数据插入到模版中，最后将信息返回给用户。

def current_datetime(request):
    now = datetime.datetime.now()
    html = "<html><body>It is now %s.</body></html>" % now
    return HttpResponse(html)

方法一

from django import template
t = template.Template('My name is {{ name }}.')
c = template.Context({'name': 'Adrian'})
print t.render(c)

方法二

import datetime
from django import template
import DjangoDemo.settings
 
now = datetime.datetime.now()
fp = open(settings.BASE_DIR+'/templates/Home/Index.html')
t = template.Template(fp.read())
fp.close()
html = t.render(template.Context({'current_date': now}))
return HttpResponse(html

方法三

from django.template.loader import get_template
from django.template import Context
from django.http import HttpResponse
import datetime
 
def current_datetime(request):
    now = datetime.datetime.now()
    t = get_template('current_datetime.html')
    html = t.render(Context({'current_date': now}))
    return HttpResponse(html)

方法四

return render_to_response('Account/Login.html',data,context_instance=RequestContext(request))

方法五

我是这么写的

2、模版语言

　模板中也有自己的语言，该语言可以实现数据展示

{{ item }}
{% for item in item_list %} <a>{{ item }}</a> {% endfor %}
　　forloop.counter
　　forloop.first
　　forloop.last
{% if ordered_warranty %} {% else %} {% endif %}
母板：{% block title %}{% endblock %}
子板：{% extends "base.html" %}
　　　{% block title %}{% endblock %}
帮助方法：
{{ item.event_start|date:"Y-m-d H:i:s"}}
{{ bio|truncatewords:"30" }}
{{ my_list|first|upper }}
{{ name|lower }}

if方法

for循环

for循环索引

反向操作

{{% empty %}}等价于做了if判断，如果为空

第一种方法：

第二种方法：

字典循环

需求，要求把输出的内容都变成大写

对时间的格式化

<li> today is {{today | date:"Y-m-d"}}

3、自定义simple_tag

a、在app中创建templatetags模块

视频里面这么干

b、创建任意 .py 文件，如：xx.py

#!/usr/bin/env python
#coding:utf-8
from django import template
from django.utils.safestring import mark_safe
from django.template.base import resolve_variable, Node, TemplateSyntaxError
  
register = template.Library()
  
@register.simple_tag
def my_simple_time(v1,v2,v3):
    return  v1 + v2 + v3
  
@register.simple_tag
def my_input(id,arg):
    result = "<input type='text' id='%s' class='%s' />" %(id,arg,)
    return mark_safe(result)

from django import template
register = template.Library()
def percent(value):
                                return value + "%"
register.filter(percent)

视频里的

c、在使用自定义simple_tag的html文件中导入之前创建的 xx.py 文件名

{% load xx %}

d、使用simple_tag

{% my_simple_time 1 2 3%}
{% my_input 'id_username' 'hide'%}

e、在settings中配置当前app，不然django无法找到自定义的simple_tag

INSTALLED_APPS = (
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
    'app01',
)

simple_tag和filter的案例

#!/usr/bin/env python
# -*- coding:utf-8 -*-
from django import template
from django.utils.safestring import mark_safe
from django.template.base import resolve_variable, Node, TemplateSyntaxError

register = template.Library()

@register.simple_tag
def my_simple_time(v1,v2,v3):
    return  v1 + v2 + v3

@register.simple_tag
def detail1(item,counter,allcount,remainder):
    temp = """
        <div style="width: 245px;">
            <img style="width: 245px;height: 200px;" src="/%s">
            <p>%s</p>
            <p>%s</p>
            <p>%s</p>
        </div>
        """
    if counter%allcount == remainder:
        temp = temp %(item['student__pic'],
                      item['student__name'],
                      item['student__salary'],
                      item['letter_of_thanks'])
        return mark_safe(temp)
    else:
        return ""

@register.simple_tag
def detail2(counter,allcount,remainder):
    """
    查看余数是否等于remainder
    :param counter:
    :param allcount:
    :param remainder:
    :return:
    """
    if counter%allcount == remainder:
        return True
    return False

templatetags_xx.py_simplate_tag

{% load xx %}
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>

    <div>

    </div>
    <style>
        .clearfix:after{
            content: '.';
            visibility: hidden;
            height: 0;
            clear: both;
            display: block;
        }
    </style>

    <div style="margin: 0 auto;width: 980px;" class="clearfix">
        <div style="width: 245px;float: left">
            {% for item in detail_list %}

                {% detail1 item forloop.counter 4 1 %}

            {% endfor %}
        </div>
        <div style="width: 245px;float: left">
            {% for item in detail_list %}
                {% detail1 item forloop.counter 4 2 %}
            {% endfor %}
        </div>
        <div style="width: 245px;float: left">
            {% for item in detail_list %}
                {% detail1 item forloop.counter 4 3 %}
            {% endfor %}

html

---------------------------------

#!/usr/bin/env python
# -*- coding:utf-8 -*-
from django import template
from django.utils.safestring import mark_safe
from django.template.base import resolve_variable, Node, TemplateSyntaxError

register = template.Library()



@register.filter
def detail3(value,arg):

    """
    查看余数是否等于remainder arg="1,2"
    :param counter:
    :param allcount:
    :param remainder:
    :return:
    """
    allcount, remainder = arg.split(',')
    allcount = int(allcount)
    remainder = int(remainder)
    if value%allcount == remainder:
        return True
    return False

filter

{% load xx %}
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>

    <div>

    </div>
    <style>
        .clearfix:after{
            content: '.';
            visibility: hidden;
            height: 0;
            clear: both;
            display: block;
        }
    </style>

    <div style="margin: 0 auto;width: 980px;" class="clearfix">

        <div style="width: 245px;float: left">
             {% for item in detail_list %}
                 {% if forloop.counter|detail3:"4,0" %}
                    <div style="width: 245px;">
                        <img style="width: 245px;height: 200px;" src="/{{ item.student__pic }}">
                        <p>{{ item.student__name }}</p>
                        <p>{{ item.student__salary }}</p>
                        <p>{{ item.letter_of_thanks }}</p>
                    </div>
                 {% endif %}

            {% endfor %}

        </div>
    </div>

</body>
</html>