Django Rest框架分页设置 - 内容范围 [英] Django Rest Framework Pagination Settings - Content-Range

问题描述

6.30.15 - 我如何使这个问题更好，更有助于其他人？反馈应该是有帮助的谢谢！

我正在使用DRF作为Dojo / Dgrid Web应用程序的服务器端。 Dojo需要来自服务器的内容范围或范围响应。目前，它不发送任何内容，因此dgrid.grid的分页工作不正常。

I am using DRF as server side to a Dojo/Dgrid web application. Dojo needs a content-range or range response from the server. Currently it doesn't send any and so the pagination for dgrid.grid isn't working properly.

在DRF文档中，它指出响应标头中包含的分页链接，如内容-Range或链接。但是，如何设置DRF API来执行此操作并没有给出明确的过程。我还是比较新的web应用程序开发。任何帮助将不胜感激！

In the DRF documentation it states" Pagination links that are included in response headers, such as Content-Range or Link." But doesn't give a clear process on HOW to set the DRF API to do this. I am still relatively new to web app development. Any help would be appreciated!

推荐答案

1。包括链接标题作为回应：

1. Including Link Header in response:

要包含链接 header在你的响应中，你需要创建一个自定义分页序列化器类，这应该是子类 pagination.BasePagination 并覆盖 get_paginated_response（自我，数据）方法。

示例（取自 docs ）：

Example (taken from docs):

假设我们要用包含 Link 头中的下一个和前一个链接的修改格式替换默认分页输出样式，我们覆盖 get_paginated_response（ ）。

Suppose we want to replace the default pagination output style with a modified format that includes the next and previous links in a Link header, we override the get_paginated_response() .

class LinkHeaderPagination(pagination.PageNumberPagination):

    def get_paginated_response(self, data):
        next_url = self.get_next_link()
        previous_url = self.get_previous_link()

        if next_url is not None and previous_url is not None:
            link = '<{next_url}; rel="next">, <{previous_url}; rel="prev">'
        elif next_url is not None:
            link = '<{next_url}; rel="next">'
        elif previous_url is not None:
            link = '<{previous_url}; rel="prev">'
        else:
            link = ''

        link = link.format(next_url=next_url, previous_url=previous_url)
        headers = {'Link': link} if link else {}

        return Response(data, headers=headers)

此后，我们需要在我们的设置中包含此分页类，以便DRF使用它，而不是默认的分页类。

After this, we need to include this pagination class in our settings so that it is used by DRF instead of the default pagination classes.

REST_FRAMEWORK = {
    'DEFAULT_PAGINATION_CLASS': 'my_project.apps.core.pagination.LinkHeaderPagination',
    'PAGE_SIZE': 100
}

列表端点的API响应现在将包含一个 Link 头。

API responses for list endpoints will now include a Link header.

2。包含内容范围标题作为回应：

2. Including Content-Range Header in response:

您还可以发送内容范围标题而不是链接。只需创建一个标题字典，其中包含 Content-Range 作为键和值，返回多少个项目以及存在多少个项目。

You can also send Content-Range header instead of Link. Just create a headers dictionary with Content-Range as the key and value as how many items are being returned and how many total items exist.

例如：

class ContentRangeHeaderPagination(pagination.PageNumberPagination):

    def get_paginated_response(self, data):
        total_items = self.page.paginator.count
        item_starting_index = self.page.start_index() - 1 # In a page, indexing starts from 1
        item_ending_index = self.page.end_index() - 1

        content_range = 'items {0}-{1}/{2}'.format(item_starting_index, item_ending_index, total_items)      

        headers = {'Content-Range': content_range} 

        return Response(data, headers=headers)

假设这是收到的标题：

Content-Range: items 0-9/50 

这告诉我们r请求具有内容范围标题，值为项目0-9 / 50 。这表示前10个项目从总计 50 中退回。

This tells us that the response has a Content-Range header with value as items 0-9/50. This indicates that first 10 items are returned out of total 50.

您还可以使用 * 而不是总数。的项目，如果计算总额是昂贵的。

You can also use * instead of total no. of items if calculating total is expensive.

Content-Range: items 0-9/* # Use this if total is expensive to calculate

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