• Django 08


    sweetalert弹窗

    • 下载sweetalert并存放在Django项目中的静态文件夹中 https://github.com/MrBigBlake/bootstrap-sweetalert
    • 选择想要的弹窗样式直接copy过来快乐的改呀改https://lipis.github.io/bootstrap-sweetalert/
    • 如何查找到for循环中的a标签: 可以添加一个类属性
    • 通过DOM操作直接移除页面上已经被删除的数据标签
    # 通过sweetalert实现删除数据时触发弹窗, 确认是否删除
    def home(request):
        user_queryset = models.User.objects.all()
        if request.is_ajax():
            back_dic = {'code': 1000, 'msg': ''}
            print(request.POST)
            delete_id = int(request.POST.get('delete_id')[0])
            time.sleep(2)
            models.User.objects.filter(pk=delete_id).delete()
            back_dic['msg'] = 'Data has been deleted'
            return JsonResponse(back_dic)
        return render(request, 'home.html', locals())
    
    <!DOCTYPE html>
    <html lang="en">
    <head>
        <meta charset="UTF-8">
        <title>Title</title>
        {% load  static %}
        <script src="{% static 'JQuery-3.4.1/JQuery.js' %}"></script>
        <script src="{% static 'bootstrap-3.3.7-dist/js/bootstrap.min.js' %}"></script>
        <script src="{% static 'bootstrap-sweetalert-master/dist/sweetalert.min.js' %}"></script>
        <link rel="stylesheet" href="{% static 'bootstrap-sweetalert-master/dist/sweetalert.css' %}">
        <link rel="stylesheet" href="{% static 'bootstrap-3.3.7-dist/css/bootstrap.min.css' %}">
    </head>
    <body>
    <div class="container">
        <div class="row"></div>
        <div class="col-md-8 col-md-offset-2">
            <h1 class="text-center">User Info</h1>
            <table class="table table-hover table-bordered table-striped">
                <thead>
                <tr>
                    <th>NO.</th>
                    <th>Username</th>
                    <th>Age</th>
                    <th>Gender</th>
                    <th class="text-center">Actions</th>
                </tr>
                </thead>
                <tbody>
                {% for user in user_queryset %}
                    <tr>
                        <td>{{ forloop.counter }}</td>
                        <td>{{ user.username }} </td>
                        <td>{{ user.age }} </td>
                        <td>{{ user.get_gender_display }} </td>
                        <td class="text-center">
                            <a href="#" class="btn btn-primary btn-sm">Edit</a>
                            {#给a标签加一个cancel类以便定位到该标签#}
                            <a href="#" class="btn btn-danger btn-sm cancel" id={{ user.pk }}>Delete</a>
                        </td>
                    </tr>
                {% endfor %}
                </tbody>
            </table>
        </div>
    </div>
    
    <script>
        $(".cancel").click(function () {
            let $btn = $(this);
            swal({
                    title: "Are you sure?",
                    text: "You will not be able to recover this imaginary file!",
                    type: "warning",
                    showCancelButton: true,
                    confirmButtonClass: "btn-danger",
                    confirmButtonText: "Yes, delete it!",
                    cancelButtonText: "No, cancel plx!",
                    closeOnConfirm: false,
                    closeOnCancel: false,
                    showLoaderOnConfirm: true
                },
                function (isConfirm) {
                    if (isConfirm) {
                        $.ajax({
                            url: "",
                            type: "post",
                            data: {"delete_id": $btn.attr('id')},
                            success: function (data) {
                                if (data.code==1000) {
                                    swal("Deleted!", "Data has been deleted.", "success");
                                    {#通过DOM操作直接将删除的标签移除#}
                                    $btn.parent().parent().remove()
                                } else {
                                    swal("Error", "Unknown error", "warning");
                                }
                            }
                        });
                    } else {
                        swal("Cancelled", "Data delete has been cancelled :)", "error");
                    }
                })
        });
    </script>
    </body>
    </html>
    

    bulk-create

    • 用于向数据库中批量添加数据
    • 先将数据对象都添加到列表中, 然后将该列表传给bulk_create方法
    # 这样向数据库添加大量数据速度非常慢, 甚至会导致程序崩溃 
    for i in range(10000):
        models.Book.objects.create(title=f'book-{i}')
        
    # 使用bulk_create方法可快速向数据库中添加大量数据对象    
    lis = []
    for i in range(10000):
        obj = models.Book(title=f'book-{i}')
        lis.append(obj)
    models.Book.objects.bulk_create(lis) 
    

    自定义分页器

    • queryset对象支持切片操作
    • 可以直接向html文件发送html代码(字符串格式)
    # 实现简单的分页展示效果
    def index(request):
        # 分页器一次展示的页数为 page_controller * 2 + 1
        page_controller = 3
        if page_controller < 1:
            page_controller = 1
            
        # 数据库图书个数
        book_num = models.Book.objects.all().count()
        per_page_num = 5
        
        # 判断一共有多少页
        page_num, more = divmod(book_num, per_page_num)
        if more:
            page_num += 1
    
        # 获取当前页数, 设置默认值为1
        page_init = int(request.GET.get('page', 1))
        page = page_init
    
        # 防止分页器末尾超出总页数
        if page_init > page_num - page_controller:
            page = page_num - page_controller
    
        # 防止分页器开头出现0或负数页
        if page_init < page_controller + 1:
            page = page_controller + 1
    
        # 切片操作的起始和结束位置
        page_start = (page_init - 1) * per_page_num
        page_end = page_init * per_page_num
    
        # 切片获取当前页数对应的图书数据
        book_queryset = models.Book.objects.all()[page_start: page_end]
    
        # 直接向html文件发送html代码
        html = ''
        for i in range(page - page_controller, page + page_controller + 1):
    
            # 当前页标签高亮
            if i == page_init:
                html += f'<li class="active"><a href="?page={i}">{i}</a></li>'
            else:
                html += f'<li><a href="?page={i}">{i}</a></li>'
    
        return render(request, 'index.html', locals())
    
    <!DOCTYPE html>
    <html lang="en">
    <head>
        <meta charset="UTF-8">
        <title>Title</title>
        {% load static %}
        <script src="{% static 'JQuery-3.4.1/JQuery.js' %}"></script>
        <script src="{% static 'bootstrap-3.3.7-dist/js/bootstrap.min.js' %}"></script>
        <link rel="stylesheet" href="{% static 'bootstrap-3.3.7-dist/css/bootstrap.min.css' %}">
    </head>
    <body>
    <div class="container">
        <div class="row">
            <div class="col-md-6 col-md-offset-3">
                <h1 class="text-center">Book List</h1>
                <table class="table table-striped table-bordered table-hover">
                    <thead>
                    <tr>
                        <th>NO.</th>
                        <th>Book Title</th>
                    </tr>
                    </thead>
                    <tbody>
                    {% for book in book_queryset %}
                        <tr>
                            <td>{{ book.pk }}</td>
                            <td>{{ book.title }}</td>
                        </tr>
                    {% endfor %}
                    </tbody>
                </table>
            <div class="text-center">
                <nav aria-label="Page navigation">
                    <ul class="pagination">
                            {{ html|safe }}
                    </ul>
                </nav>
                </div>
            </div>
        </div>
    </div>
    </body>
    </html>
    
    • 第三方分页器的使用
    • 在app文件夹或者总项目文件夹下, 新建utils文件夹, 将下面分页文件放到utils文件下
    • 两个参数: current_pageall_count
    • 将html代码字符串封装到了 pagination_obj.page_html
    # Pagination.py
    class Pagination(object):
        def __init__(self,current_page,all_count,per_page_num=10,pager_count=5):
            """
            封装分页相关数据
            :param current_page: 当前页
            :param all_count:    数据库中的数据总条数
            :param per_page_num: 每页显示的数据条数
            :param pager_count:  最多显示的页码个数
            
            用法:
            queryset = model.objects.all()
            page_obj = Pagination(current_page,all_count)
            page_data = queryset[page_obj.start:page_obj.end]
            获取数据用page_data而不再使用原始的queryset
            获取前端分页样式用page_obj.page_html
            """
            try:
                current_page = int(current_page)
            except Exception as e:
                current_page = 1
    
            if current_page <1:
                current_page = 1
    
            self.current_page = current_page
    
            self.all_count = all_count
            self.per_page_num = per_page_num
    
    
            # 总页码
            all_pager, tmp = divmod(all_count, per_page_num)
            if tmp:
                all_pager += 1
            self.all_pager = all_pager
    
            self.pager_count = pager_count
            self.pager_count_half = int((pager_count - 1) / 2)
    
        @property
        def start(self):
            return (self.current_page - 1) * self.per_page_num
    
        @property
        def end(self):
            return self.current_page * self.per_page_num
    
        def page_html(self):
            # 如果总页码 < 11个:
            if self.all_pager <= self.pager_count:
                pager_start = 1
                pager_end = self.all_pager + 1
            # 总页码  > 11
            else:
                # 当前页如果<=页面上最多显示11/2个页码
                if self.current_page <= self.pager_count_half:
                    pager_start = 1
                    pager_end = self.pager_count + 1
    
                # 当前页大于5
                else:
                    # 页码翻到最后
                    if (self.current_page + self.pager_count_half) > self.all_pager:
                        pager_end = self.all_pager + 1
                        pager_start = self.all_pager - self.pager_count + 1
                    else:
                        pager_start = self.current_page - self.pager_count_half
                        pager_end = self.current_page + self.pager_count_half + 1
    
            page_html_list = []
            # 添加前面的nav和ul标签
            page_html_list.append('''
                        <nav aria-label='Page navigation>'
                        <ul class='pagination'>
                    ''')
            first_page = '<li><a href="?page=%s">首页</a></li>' % (1)
            page_html_list.append(first_page)
    
            if self.current_page <= 1:
                prev_page = '<li class="disabled"><a href="#">上一页</a></li>'
            else:
                prev_page = '<li><a href="?page=%s">上一页</a></li>' % (self.current_page - 1,)
    
            page_html_list.append(prev_page)
    
            for i in range(pager_start, pager_end):
                if i == self.current_page:
                    temp = '<li class="active"><a href="?page=%s">%s</a></li>' % (i, i,)
                else:
                    temp = '<li><a href="?page=%s">%s</a></li>' % (i, i,)
                page_html_list.append(temp)
    
            if self.current_page >= self.all_pager:
                next_page = '<li class="disabled"><a href="#">下一页</a></li>'
            else:
                next_page = '<li><a href="?page=%s">下一页</a></li>' % (self.current_page + 1,)
            page_html_list.append(next_page)
    
            last_page = '<li><a href="?page=%s">尾页</a></li>' % (self.all_pager,)
            page_html_list.append(last_page)
            # 尾部添加标签
            page_html_list.append('''
                                               </nav>
                                               </ul>
                                           ''')
            return ''.join(page_html_list)
    
    def index(request):
    	book_queryset = models.Book.objects.all()
        # 两个参数, 当前页和数据数量
        current_page = request.GET.get('page', 1)
        all_count = book_queryset.count()
        # 实例化出分页器对象
        pagination_obj = Pagination(current_page=current_page, all_count=all_count)
        # 切片获取当前页的数据
        page_queryset = book_queryset[pagination_obj.start:pagination_obj.end]
        return render(request, 'index.html', locals())
    
    <table class="table table-striped table-bordered table-hover">
                    <thead>
                    <tr>
                        <th>NO.</th>
                        <th>Book Title</th>
                    </tr>
                    </thead>
                    <tbody>
                    {% for book in page_queryset %}
                        <tr>
                            <td>{{ book.pk }}</td>
                            <td>{{ book.title }}</td>
                        </tr>
                    {% endfor %}
                    </tbody>
                </table>
            <div class="text-center">
                {{ pagination_obj.page_html|safe }}
                </div>
            </div>
    
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  • 原文地址:https://www.cnblogs.com/bigb/p/11973399.html
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