Question

我一直在努力学习并在Django中使用分页来处理ListViews，但我似乎在理解概念方面遇到了一些麻烦。所以，让我展示一些代码 - 我的view.py看起来像这样：

class SearchDisplayListView(ListView):
    model = BlogPosts
    template_name = "searchres_list.html"
    paginate_by = '15'
    context_object_name = "searchres"

    def get_context_data(self, **kwargs):
        context = super(SearchDisplayListView, self).get_context_data(**kwargs)
        q = self.request.GET.get('q')
        q = q.replace(" ","+")
        context['searchq'] = q
        return context

    def get_queryset(self):
        queryset = super(SearchDisplayListView, self).get_queryset()
        # Get the q GET parameter
        q = self.request.GET.get('q')
        q = q.replace(" ","+")
        if q is None:
        # Return the base queryset
        return queryset
        # Return a filtered queryset
       ## do some awesome calculations using "q" i.e send request to search server
       ## get back a list from the search server.. example: range(0,100)
        queryset = range(0,100)
        return queryset

正如您所看到的，我实际上并没有使用模型填充我的查询集 - 而是使用我自己的“搜索服务器”来返回结果 - 例如在此示例范围（0,100）中。

现在，我正在尝试在模板代码中使用以下内容：

<table class="table table-hover">
<tbody>
{% for i in searchres %}
<tr>
<td><img src="http://placehold.it/140x140" class="img-polaroid"></td>
<td>{{i}}</td>
</tr>
{% endfor %}
</tbody>
</table>

我的分页看起来如下：

{% if is_paginated %}
<div class="pagination pagination-centered">
    <ul>
        {% if page_obj.has_previous %}
<li><a href="/search/?q={{searchq}}/page={{ page_obj.previous_page_number }}">Prev</a></li>
        {% endif %}

        {% for i in paginator.page_range %}
            {% if page_obj.has_next %}
<li><a href="/search/?q={{searchq}}/page={{ page_obj.number }}">{{i}}</a></li>
            {% endif %}
        {% endfor %}

        {% if page_obj.has_next %}
<li><a href="/search/?q={{searchq}}/page={{ page_obj.next_page_number }}">Next</a></li>
        {% endif %}

    </ul>
</div>

现在，我遇到以下问题：

[1]虽然模板似乎对第一组（即0到14）进行了分页，但我无法在后续页面中看到其他值。所以，当我点击下一页时，我得到：

 - http://mydata:8000/search/?q=myquery/page=2

当我再次点击下一页时，我得到：

 - http://mydata:8000/search/?q=boots/page=2/page=2

这显然是错误的。我无法看到如何产生：

 - http://mydata:8000/search/?q=boots/page=3

[2]即使我手动设置：

 - http://mydata:8000/search/?q=boots/page=3

我再次从0到14看到值，而不是页面中的逻辑集：3。

此外，这基本上告诉我，在每个页面上，get_queryset似乎都在运行，生成前0到14的值 - 这不是我想要的。

正如您所看到的，我在get_queryset中拥有自己的自定义数据集 - 而不是任何数据库交互 - 因此，我不确定如何对此自定义数据进行分页。

感谢您抽出时间阅读我相当长的帖子！

Answer 1

查询参数必须用＆amp;分隔。不是/

/search/?q={{searchq}}/page={{ page_obj.previous_page_number }}

应该是：

/search/?q={{searchq}}&page={{ page_obj.previous_page_number }}

此外，最佳做法是使用URL解析器而不是对网址进行硬编码，例如：

{% url 'search' searchq page_obj.previous_page_number %}

Answer 2

仅供记录，代码应为：

{% if is_paginated %}
    <div class="pagination pagination-centered">
    <ul>
    {% if page_obj.has_previous %}
        <li><a href="/search/?q={{searchq}}&page={{ page_obj.previous_page_number}}">Prev</a></li>
    {% endif %}

    {% if page_obj.has_next %}
       {% for i in paginator.page_range %}
          <li><a href="/search/?q={{searchq}}&page={{ i }}">{{i}}</a></li>
        {% endfor %}
          <li><a href="/search/?q={{searchq}}&page={{ page_obj.next_page_number }}">Next</a></li>
    {% endif %}

</ul>
</div>

有两处变化：1。page_obj.number返回实际页面，因此它被增量变量i替换。 2.为了清楚起见，for循环在page_obj.has_next内移动。如果你这样做的话，只有当提问者有超过这个页面时才会显示页面编号链接。如果你想要显示它：只需将其移出。

Answer 3

在研究了这个问题一段时间后，从这个条目开始，我最终得到了一个复杂但通用的可重用解决方案。

对OP来说过度杀伤，但很多人似乎都有分页和搜索问题，所以这里是我的$ .02。

（Django的新手，所以我相信有些事情需要改进，但我现在能够很快地将搜索和分页结合起来。请忽略关于＆＃39; db＆＃39的任何事情;或者＆＃39; mdb＆＃39;，这非常特定于我的应用程序，它经常在Django数据库之外执行原始SQL。）

<强>梗概：

基本上，我认为我可以一石二鸟。我正在处理过滤行集的原因是因为我从表单开始搜索。

并且......表单能够提供重建分页URL所需的信息。

因此，基本上结束了一个系统，其中的工作主要包括构建一个普通的搜索表单，然后用适当的子类型ListView连接它。请参阅RoleListView类。

我还需要创建listview的模板，但是如果您参考它，@ pssecurity / security_list.html您会发现它非常基本。

<强>详细信息：

关于分页的智慧在类KSearchListView（ListView）上。这个东西是完全通用的，我可以在我想要的尽可能多的搜索页面上重复使用它。

方法get_queryset，通过调用form.doSearch进行数据库过滤。

实际分页是在方法get_context_data上，它检查是否有表单，如果它是有效的，然后通过使用表单的已清理参数重新填充它来操作分页URL。

另请注意，有两个传入的URL，一个未过滤，列表，一个过滤，搜索）。两者都映射到相同的ListView。

urls

    #Roles aka PSROLEDEFN
    url(r'^roles/search',
        login_required(RoleListView.as_view()),
        name="psroledefn_search"),

    url(r'^roles/$',
        # 'pssecurity.views.psroledefn_list',
        login_required(RoleListView.as_view()),
        name="psroledefn_list"),



        #generic
class KSearchListView(ListView):
    def __str__(self):
        return self.__class__.__name__

    __repr__ = __str__

    form_class = form = None
    di_hardcoded_context = {}

    def setdb(self):
        #specific to my app
        self.db = self.rdb

    def dispatch(self,*args,**kwargs):
        #specific to my app
        if not self.mdb:
            self.mdb = MultiDb.get(self.kwargs["dbr"])
            self.djangodb = self.mdb.djangodb
            self.rdb = self.mdb.rdb
            self.setdb()
        #specific to my app

        return super(KSearchListView, self).dispatch(*args,**kwargs)

    def get_queryset(self,*args,**kwargs):
        # logging.info("%s.get_queryset(%s,%s)" % (self,args,kwargs))

        self.request.get = self.request.GET

        if self.form_class:
            #pagination info
            #do we have a form and are we coming from it?
            if self.request.method == "GET":
                self.form = self.form_class(self.db, self.request.GET)

                if self.form.is_valid():
                    logging.info("form.doSearch")
                    li_c = self.form.doSearch()
                    return li_c
                else:
                    logging.debug("not is_valid branch")
            else:
                self.form = self.form_class(self.mdb.rdb)
        #fetch all rows for the underlying table
        return self.fetch_all()

    def fetch_all(self):
        #specific to my app
        #you would probably use a <model>.objects.all()
        return list(pssys.Pssys.fetch(self.db,self.recname))


    def _override_context_data(self,context):
        pass

    def get_context_data(self,*args,**kwargs):
        # logging.info("%s.get_context_data(%s,%s)" % (self,args,kwargs))

        context = super(KSearchListView, self).get_context_data(**kwargs)
        context['form'] = self.form
        context["dbr"] = self.mdb.rdbname


        #pagination info
        #we are going to put the GET variables right back into the next/prev
        url = ""
        page_obj = context["page_obj"]
        if self.form and self.form.is_valid() and self.form.cleaned_data:

            li = [self.request.path,"?"]

            #driving the url assembly from the form fields and
            #using the cleaned data should be pretty safe
            di = self.form.cleaned_data
            for k in self.form.fields:
                li.append("%s=%s" % (k,di[k]))
                li.append("&")
            # li = li[:-1]
            url = "".join(li)

        #if we didn't come in through a search form
        if not url:
            url = "?"

        #now conditionally add the previous/next as appropriate. 
        #url has either a trailing ? or & at this point
        kpaging_previous_url = kpaging_next_url = ""
        if page_obj.has_previous():
            kpaging_previous_url = context["kpaging_previous_url"] = url + "page=%s" % (page_obj.previous_page_number())
        if page_obj.has_next():
            kpaging_next_url = context["kpaging_next_url"] = url + "page=%s" % (page_obj.next_page_number())

        logging.debug("url:%s" % (url))
        logging.debug("kpaging_previous_url:%s" % (kpaging_previous_url))
        logging.debug("kpaging_next_url:%s" % (kpaging_next_url))

        #pickup anything the subclass has set for the context
        context.update(self.di_hardcoded_context)
        self._override_context_data(context)
        return context


        #what I need to write for every list/search page...

class RoleListView(KSearchListView):

    template_name = "pssecurity/security_list.html" 
    paginate_by = 20
    recname = "PSROLEDEFN"
    form_class = Search_PSROLEDEFN
    di_hardcoded_context = dict(
        title="Search Roles",
        header="Roles",
        templatename_inst="PSROLEDEFN_list",
        url_action='security:psroledefn_search')

#pagination info the forms

        #generic
class SearchForm(forms.Form):
    def __init__(self, db, request=None):
        self.db = db
        li_arg = [request] if request else []

        super(forms.Form, self).__init__(*li_arg)

    def __str__(self):
        return self.__class__.__name__

    __repr__ = __str__


        #what I need to write for every list/search page...
class Search_PSROLEDEFN(SearchForm):
    ROLENAME = forms.CharField(max_length=20, required=False)
    DESCR = forms.CharField(max_length=32, required=False)

    status_custom = ChooseStatusCustomizationField()
    hasUsers = ChooseYesNoDontCareField("has Users?")
    hasPermissions = ChooseYesNoDontCareField("has Permissions?")
    hasPortalReferences = ChooseYesNoDontCareField("has Portal?")

    def doSearch(self):

        ROLENAME = self.cleaned_data["ROLENAME"]
        DESCR = self.cleaned_data["DESCR"].strip()
        status_custom = self.cleaned_data["status_custom"]

        hasPortalReferences = self.cleaned_data["hasPortalReferences"]
        hasPermissions = self.cleaned_data["hasPermissions"]
        hasUsers = self.cleaned_data["hasUsers"]

        #cut out a lot of code specific to my app
        #you would want to do an appropriate
        #<model>.objects.filter()...
        returns <select from my db>




#a typical template, note that isn't even specific to an object
#refer to class RoleListView to see how the template is built.
#the actual details of the fetched objects are left to <templatename_inst>

pssecurity/security_list.html
{% block search %}
<div id="block_search">
<span>{{header}}</span>

<div class="row">
{% if form %}

<div id="search" class="well col-xs-9" >
    <form class= "form-horizontal" action="{% url url_action dbr=dbr %}" method="get">
        {{form.as_table}}
        <input type="submit" value="search">
    </form>
</div>
{% endif %}
{% endblock %}

{%block content %}
<div id = "block_content">
{% for inst in object_list %}
    <div class="row">
        {% include templatename_inst %}
    </div>
{% endfor %}

{% include "websec/kpagination.html" %}

</div>
{%endblock %}

        #generic
kpagination.html
<div class="pagination">
    <span class="step-links" >
        {% if li_inst.has_previous %}
            <a href="?page={{ li_inst.previous_page_number }}">previous</a>
        {% endif %}

        <span class="current" >
            Page {{ li_inst.number }} of {{ li_inst.paginator.num_pages }}.
        </span>

        {% if li_inst.has_next %}
            <a \href="?page={{ li_inst.next_page_number }}">next</a>
        {% endif %}
    </span>
</div>

Answer 4

我们可以在django classbased Listview中进行以下操作

views.py

try:
    from urllib import urlencode
except ImportError:
    from urllib.parse import urlencode

class MyListView(ListView):
    # ............
    def get_context_data(self, *args, **kwargs):
        context = super(
            GroupSubsListView, self
        ).get_context_data(*args, **kwargs)
        query_params = self.request.GET.copy()
        query_params.pop('page', None)
        context['query_params'] = urlencode(query_params)
        return context

template.html

<!-- pagination -->
{% if is_paginated %}
  <p>showing {{ page_obj.start_index }} to {{ page_obj.end_index }} of {{ page_obj.paginator.count }}</p>
  <div class="text-center">
    <nav>
      <ul class="pagination">
        {% if page_obj.has_previous %}
        <li class="page-item">
          <a class="page-link" href="?page={{ page_obj.previous_page_number }}&{{ query_params }}" aria-label="Previous">
            Previous
          </a>
        </li>
        {% endif %}
        <li class="page-item"><a class="page-link"> Page {{ page_obj.number }} of {{ page_obj.paginator.num_pages }}. </a></li>
        {% if page_obj.has_next %}
        <li class="page-item">
          <a class="page-link" href="?page={{ page_obj.next_page_number }}&{{ query_params }}" aria-label="Next">
            Next
          </a>
        </li>
        {% endif %}
      </ul>
    </nav>
  </div>
{% endif %}
  <!-- end/ -->

使用get_queryset的Django ListView分页

4 个答案: