stark组件（1）：动态生成URL

项目启动时自动生成URL

效果图：

知识点：

1. Django启动前通过apps下的ready方法执行一个可以生成URL的py文件
2. include函数主要返回有三个元素的一个元组。第一个是url配置（urlpatterns），第二个是app（app_name），第三个是命名空间（namespace）。
3. 通过单例模式，我们反复操作一个对象。

项目名：stark_practice

业务app：web

stark app：stark

一、在业务表中生成数据库

web/models.py

from django.db import models

class Department(models.Model):
    """
    部门表
    """
    title = models.CharField(verbose_name='部门名称', max_length=32)

class UserInfo(models.Model):
    """
    用户表
    """
    name = models.CharField(verbose_name='姓名', max_length=32)
    age = models.CharField(verbose_name='年龄', max_length=32)
    email = models.CharField(verbose_name='邮箱', max_length=32)
    department = models.ForeignKey(verbose_name='部门', to='Department', on_delete=models.CASCADE)

二、加载django项目时自动执行stark文件

stark.apps.py

from django.apps import AppConfig
from django.utils.module_loading import autodiscover_modules

class StarkConfig(AppConfig):
    name = 'stark'

    def ready(self): 
        autodiscover_modules('stark')  # 执行名为stark的py文件

三、stark组件

stark/service/core_function.py

from django.urls import re_path

class StarkSite(object):
    def __init__(self):
        self._registry = []
        self.app_name = 'stark'
        self.namespace = 'stark'

    def register(self, model_class, handler_class):
        """
        :param model_class: 是models中的数据库表对应的类。
        :param handler_class: 处理请求的视图函数所在的类
        :return:
        """
        """
        self._registry = [
           {'model_class': model.Department,'handler':DepartmentHandler(models.Department)},
           {'model_class': model.UserInfo,'handler':UserInfo(models.UserInfo)},
           {'model_class': model.Host,'handler':Host(models.Host)},
        ]
        """
        # 注意：handler_class接收的第一个参数是数据库表对应的类
        self._registry.append({'model_class': model_class, 'handler': handler_class(model_class)})

    def get_urls(self):
        patterns = []
        for item in self._registry:
            model_class = item['model_class']
            handler = item['handler']
            app_name = model_class._meta.app_label  # 获取当前类所在的app
            model_name = model_class._meta.model_name  # 获取当前类所在的表名称
            patterns.append(re_path(r'%s/%s/list' % (app_name, model_name), handler.list_view))
            patterns.append(re_path(r'%s/%s/add' % (app_name, model_name), handler.add_view))
            patterns.append(re_path(r'%s/%s/edit' % (app_name, model_name), handler.edit_view))
            patterns.append(re_path(r'%s/%s/delete' % (app_name, model_name), handler.delete_view))

        return patterns

    @property
    def urls(self):
        return self.get_urls(), self.app_name, self.namespace

site = StarkSite()

四、使用strak组件

web/stark.py

from django.shortcuts import HttpResponse
from stark.service.core_func import site

from web import models

class DepartmentHandler(object):
    def __init__(self, model_class):
        self.model_class = model_class

    def list_view(self, request):
        """
        列表页面
        :param request:
        :return:
        """
        return HttpResponse('列表页面')

    def add_view(self, request):
        """
        添加页面
        :param request:
        :return:
        """
        return HttpResponse('添加页面')

    def edit_view(self, request):
        """
        编辑页面
        :param request:
        :return:
        """
        return HttpResponse('编辑页面')

    def delete_view(self, request):
        """
        删除页面
        :param request:
        :return:
        """
        return HttpResponse('删除页面')

class UserInfoHandler:
    def __init__(self, model_class):
        self.model_class = model_class

    def list_view(self, request):
        """
        列表页面
        :param request:
        :return:
        """
        return HttpResponse('列表页面')

    def add_view(self, request):
        """
        添加页面
        :param request:
        :return:
        """
        return HttpResponse('添加页面')

    def edit_view(self, request):
        """
        编辑页面
        :param request:
        :return:
        """
        return HttpResponse('编辑页面')

    def delete_view(self, request):
        """
        删除页面
        :param request:
        :return:
        """
        return HttpResponse('删除页面')

site.register(models.Department, DepartmentHandler)
site.register(models.UserInfo, UserInfoHandler)

五、注册URL

stark_practice/urls.py

from django.contrib import admin
from django.urls import path, re_path

from stark.service.core_func import site

urlpatterns = [
    path('admin/', admin.site.urls),
    re_path(r'^stark/', site.urls),

]