修改所有页面的 paginate_by 的值

Question

我对@9​​87654321@的回答有一个后续问题

我在 HTML 中添加了以下内容

<form method="GET">
   <select name="paginate_by" id="">
        <option value="5">5</option>
        <option value="10">10</option>
        <option value="20">20</option>
        <option value="50">50</option>
   </select>
   <input type="submit" value="Paginate">
</form>

这个函数在我的ListView 类中

class ReviewPostListView(ListView):
    model = Reviews
    template_name = 'reviews/reviews.html'
    context_object_name = 'rows'
    ordering = ['id']
    paginate_by = 5

    def get_paginate_by(self, queryset):
        return self.request.GET.get("paginate_by", self.paginate_by)

它运行良好，paginate_by 已添加到 URL。我的问题是当我点击第二页时它会回到 5。

这是我的分页 HTML

{% if is_paginated %}
    {% if page_obj.has_previous %}
        <a class="btn btn-outline-info mb-4" href="?page=1">First</a>
        <a class="btn btn-outline-info mb-4" href="?page={{ page_obj.previous_page_number }}">Previous</a>
    {% endif %}
    {% for num in page_obj.paginator.page_range %}
        {% if page_obj.number == num %}
            <a class="btn btn-info mb-4" href="?page={{ num }}">{{num}}</a>
        {% elif num > page_obj.number|add:'-3' and num < page_obj.number|add:'3' %}
            <a class="btn btn-outline-info mb-4" href="?page={{ num }}">{{num}}</a>
        {% endif %}
    {% endfor %}
    {%if page_obj.has_next %}
        <a class="btn btn-outline-info mb-4" href="?page={{page_obj.next_page_number}}">Next</a>
        <a class="btn btn-outline-info mb-4" href="?page={{ page_obj.paginator.num_pages }}">Last</a>
    {% endif %}
{% endif %}

在页面上循环时在 URL 中保留 paginate_by（如果存在）参数的 Pythonic 是什么？

Answer 1

使用{{ request.GET.paginate_by }}，您可以访问模板中的paginate_by 查询参数。

因此，您的分页 HTML 将如下所示：

{% if is_paginated %}
  {% firstof request.GET.paginate_by "5" as paginate_by %}
    {% if page_obj.has_previous %}
        <a class="btn btn-outline-info mb-4" href="?page=1&paginate_by={{ paginate_by }}">First</a>
        <a class="btn btn-outline-info mb-4" href="?page={{ page_obj.previous_page_number }}">Previous</a>
    {% endif %}
    {% for num in page_obj.paginator.page_range %}
        {% if page_obj.number == num %}
            <a class="btn btn-info mb-4" href="?page={{ num }}">{{num}}</a>
        {% elif num > page_obj.number|add:'-3' and num < page_obj.number|add:'3' %}
            <a class="btn btn-outline-info mb-4" href="?page={{ num }}">{{num}}</a>
        {% endif %}
    {% endfor %}
    {%if page_obj.has_next %}
        <a class="btn btn-outline-info mb-4" href="?page={{page_obj.next_page_number}}&paginate_by={{ paginate_by }}">Next</a>
        <a class="btn btn-outline-info mb-4" href="?page={{ page_obj.paginator.num_pages }}&paginate_by={{ paginate_by }}">Last</a>
    {% endif %}

{% endif %}

firstof 会将paginate_by 的值设置为查询参数或5，这将是默认值。

Answer 2

您可以创建一个模板标签来为您处理查询参数。

这里有两个简单的标签

@register.simple_tag(takes_context=True)
def add_get_param(context, **kwargs):
    "Used to add/replace query parameters to the current URL."
    params = context["request"].GET.dict()
    params.update(kwargs)
    return "?{}".format(urlencode(params))


@register.simple_tag(takes_context=True)
def remove_get_param(context, *args):
    "Used to remove query parameters from the current URL."
    params = context["request"].GET.dict()
    for key in args:
        params.pop(key, None)
    return "?{}".format(urlencode(params))

你的 HTML 看起来像

{% if is_paginated %}
    {% if page_obj.has_previous %}
        <a class="btn btn-outline-info mb-4" href="?paginate_by={% add_get_param page=1 %}">First</a>
        <a class="btn btn-outline-info mb-4" href="{% add_get_param page=page_obj.previous_page_number %}">Previous</a>
    {% endif %}
    {% for num in page_obj.paginator.page_range %}
        {% if page_obj.number == num %}
            <a class="btn btn-info mb-4" href="{% add_get_param page=num %}">{{num}}</a>
        {% elif num > page_obj.number|add:'-3' and num < page_obj.number|add:'3' %}
            <a class="btn btn-outline-info mb-4" href="?paginate_by={{ paginate_by}}&page={{ num }}">{{num}}</a>
        {% endif %}
    {% endfor %}
    {%if page_obj.has_next %}
        <a class="btn btn-outline-info mb-4" href="{% add_get_param page=page_obj.next_page_number %}">Next</a>
        <a class="btn btn-outline-info mb-4" href="{% add_get_param page={{ page_obj.paginator.num_pages %}">Last</a>
    {% endif %}
{% endif %}

有了这个，查询参数中已经存在的任何东西都将继续存在，只有页面会被更改。因此，如果您决定添加更多参数（例如过滤），则此方法有效。

Answer 3

你可以在你的 HTML 模板中试试这个：

<select name="paginate_by" onchange="location = this.value;">
      <option value="">select</option>
      <option value="?paginate_by=5&{{page_obj.number}}">5</option>
      <option value="?paginate_by=10&{{page_obj.number}}">10</option>
      <option value="?paginate_by=20&{{page_obj.number}}">20</option>
      <option value="?paginate_by=50&{{page_obj.number}}">50</option>
</select>

将paginate_by 对象传递到html 中并将其添加到分页链接中。见以下代码：

{% if is_paginated %}
    {% if page_obj.has_previous %}
        <a class="btn btn-outline-info mb-4" href="?paginate_by={{ paginate_by}}&page=1">First</a>
        <a class="btn btn-outline-info mb-4" href="?paginate_by={{ paginate_by}}&page={{ page_obj.previous_page_number }}">Previous</a>
    {% endif %}
    {% for num in page_obj.paginator.page_range %}
        {% if page_obj.number == num %}
            <a class="btn btn-info mb-4" href="?paginate_by={{ paginate_by}}&page={{ num }}">{{num}}</a>
        {% elif num > page_obj.number|add:'-3' and num < page_obj.number|add:'3' %}
            <a class="btn btn-outline-info mb-4" href="?paginate_by={{ paginate_by}}&page={{ num }}">{{num}}</a>
        {% endif %}
    {% endfor %}
    {%if page_obj.has_next %}
        <a class="btn btn-outline-info mb-4" href="?paginate_by={{ paginate_by}}&page={{page_obj.next_page_number}}">Next</a>
        <a class="btn btn-outline-info mb-4" href="?paginate_by={{ paginate_by}}&page={{ page_obj.paginator.num_pages }}">Last</a>
    {% endif %}
{% endif %}