Include pagination control in browsable API

6 files changed, 143 insertions, 5 deletions

diff --git a/rest_framework/pagination.py b/rest_framework/pagination.py
index b9d48796..bd343c0d 100644
--- a/rest_framework/pagination.py
+++ b/rest_framework/pagination.py
@@ -3,14 +3,18 @@ Pagination serializers determine the structure of the output that should
 be used for paginated responses.
 """
 from __future__ import unicode_literals
+from collections import namedtuple
 from django.core.paginator import InvalidPage, Paginator as DjangoPaginator
+from django.template import Context, loader
 from django.utils import six
 from django.utils.translation import ugettext as _
 from rest_framework.compat import OrderedDict
 from rest_framework.exceptions import NotFound
 from rest_framework.response import Response
 from rest_framework.settings import api_settings
-from rest_framework.templatetags.rest_framework import replace_query_param
+from rest_framework.templatetags.rest_framework import (
+    replace_query_param, remove_query_param
+)
 
 
 def _strict_positive_int(integer_string, cutoff=None):
@@ -35,6 +39,49 @@ def _get_count(queryset):
         return len(queryset)
 
 
+def _get_displayed_page_numbers(current, final):
+    """
+    This utility function determines a list of page numbers to display.
+    This gives us a nice contextually relevant set of page numbers.
+
+    For example:
+    current=14, final=16 -> [1, None, 13, 14, 15, 16]
+    """
+    assert current >= 1
+    assert final >= current
+
+    # We always include the first two pages, last two pages, and
+    # two pages either side of the current page.
+    included = set((
+        1,
+        current - 1, current, current + 1,
+        final
+    ))
+
+    # If the break would only exclude a single page number then we
+    # may as well include the page number instead of the break.
+    if current == 4:
+        included.add(2)
+    if current == final - 3:
+        included.add(final - 1)
+
+    # Now sort the page numbers and drop anything outside the limits.
+    included = [
+        idx for idx in sorted(list(included))
+        if idx > 0 and idx <= final
+    ]
+
+    # Finally insert any `...` breaks
+    if current > 4:
+        included.insert(1, None)
+    if current < final - 3:
+        included.insert(len(included) - 1, None)
+    return included
+
+
+PageLink = namedtuple('PageLink', ['url', 'number', 'is_active', 'is_break'])
+
+
 class BasePagination(object):
     def paginate_queryset(self, queryset, request, view):
         raise NotImplemented('paginate_queryset() must be implemented.')
@@ -66,6 +113,8 @@ class PageNumberPagination(BasePagination):
     # Only relevant if 'paginate_by_param' has also been set.
     max_paginate_by = api_settings.MAX_PAGINATE_BY
 
+    template = 'rest_framework/pagination/numbers.html'
+
     def paginate_queryset(self, queryset, request, view):
         """
         Paginate a queryset if required, either returning a
@@ -104,6 +153,8 @@ class PageNumberPagination(BasePagination):
             )
             raise NotFound(msg)
 
+        # Indicate that the browsable API should display pagination controls.
+        self.mark_as_used = True
         self.request = request
         return self.page
 
@@ -139,8 +190,45 @@ class PageNumberPagination(BasePagination):
             return None
         url = self.request.build_absolute_uri()
         page_number = self.page.previous_page_number()
+        if page_number == 1:
+            return remove_query_param(url, self.page_query_param)
         return replace_query_param(url, self.page_query_param, page_number)
 
+    def to_html(self):
+        current = self.page.number
+        final = self.page.paginator.num_pages
+
+        page_links = []
+        base_url = self.request.build_absolute_uri()
+        for page_number in _get_displayed_page_numbers(current, final):
+            if page_number is None:
+                page_link = PageLink(
+                    url=None,
+                    number=None,
+                    is_active=False,
+                    is_break=True
+                )
+            else:
+                if page_number == 1:
+                    url = remove_query_param(base_url, self.page_query_param)
+                else:
+                    url = replace_query_param(url, self.page_query_param, page_number)
+                page_link = PageLink(
+                    url=url,
+                    number=page_number,
+                    is_active=(page_number == current),
+                    is_break=False
+                )
+            page_links.append(page_link)
+
+        template = loader.get_template(self.template)
+        context = Context({
+            'previous_url': self.get_previous_link(),
+            'next_url': self.get_next_link(),
+            'page_links': page_links
+        })
+        return template.render(context)
+
 
 class LimitOffsetPagination(BasePagination):
     """
diff --git a/rest_framework/renderers.py b/rest_framework/renderers.py
index c4de30db..4c002b16 100644
--- a/rest_framework/renderers.py
+++ b/rest_framework/renderers.py
@@ -592,6 +592,7 @@ class BrowsableAPIRenderer(BaseRenderer):
             'description': self.get_description(view),
             'name': self.get_name(view),
             'version': VERSION,
+            'pager': getattr(view, 'pager', None),
             'breadcrumblist': self.get_breadcrumbs(request),
             'allowed_methods': view.allowed_methods,
             'available_formats': [renderer_cls.format for renderer_cls in view.renderer_classes],
diff --git a/rest_framework/static/rest_framework/css/bootstrap-tweaks.css b/rest_framework/static/rest_framework/css/bootstrap-tweaks.css
index 36c7be48..d4a7d31a 100644
--- a/rest_framework/static/rest_framework/css/bootstrap-tweaks.css
+++ b/rest_framework/static/rest_framework/css/bootstrap-tweaks.css
@@ -185,10 +185,6 @@ body a:hover {
   color: #c20000;
 }
 
-#content a span {
-  text-decoration: underline;
- }
-
 .request-info {
   clear:both;
 }
diff --git a/rest_framework/templates/rest_framework/base.html b/rest_framework/templates/rest_framework/base.html
index e9668193..e0030981 100644
--- a/rest_framework/templates/rest_framework/base.html
+++ b/rest_framework/templates/rest_framework/base.html
@@ -119,9 +119,18 @@
                     <div class="page-header">
                         <h1>{{ name }}</h1>
                     </div>
+                    <div style="float:left">
                     {% block description %}
                         {{ description }}
                     {% endblock %}
+                    </div>
+
+                    {% if pager.mark_as_used %}
+                        <nav style="float: right">
+                        {% get_pagination_html pager %}
+                        </nav>
+                    {% endif %}
+
                     <div class="request-info" style="clear: both" >
                         <pre class="prettyprint"><b>{{ request.method }}</b> {{ request.get_full_path }}</pre>
                     </div>
diff --git a/rest_framework/templates/rest_framework/pagination/numbers.html b/rest_framework/templates/rest_framework/pagination/numbers.html
new file mode 100644
index 00000000..04045810
--- /dev/null
+++ b/rest_framework/templates/rest_framework/pagination/numbers.html
@@ -0,0 +1,27 @@
+<ul class="pagination" style="margin: 5px 0 10px 0">
+    {% if previous_url %}
+        <li><a href="{{ previous_url }}" aria-label="Previous"><span aria-hidden="true">&laquo;</span></a></li>
+    {% else %}
+        <li class="disabled"><a href="#" aria-label="Previous"><span aria-hidden="true">&laquo;</span></a></li>
+    {% endif %}
+
+    {% for page_link in page_links %}
+        {% if page_link.is_break %}
+            <li class="disabled">
+                <a href="#"><span aria-hidden="true">&hellip;</span></a>
+            </li>
+        {% else %}
+            {% if page_link.is_active %}
+                <li class="active"><a href="{{ page_link.url }}">{{ page_link.number }}</a></li>
+            {% else %}
+                <li><a href="{{ page_link.url }}">{{ page_link.number }}</a></li>
+            {% endif %}
+        {% endif %}
+    {% endfor %}
+
+    {% if next_url %}
+        <li><a href="{{ next_url }}" aria-label="Next"><span aria-hidden="true">&raquo;</span></a></li>
+    {% else %}
+        <li class="disabled"><a href="#" aria-label="Next"><span aria-hidden="true">&raquo;</span></a></li>
+    {% endif %}
+</ul>
diff --git a/rest_framework/templatetags/rest_framework.py b/rest_framework/templatetags/rest_framework.py
index 69e03af4..bf159d8b 100644
--- a/rest_framework/templatetags/rest_framework.py
+++ b/rest_framework/templatetags/rest_framework.py
@@ -26,6 +26,23 @@ def replace_query_param(url, key, val):
     return urlparse.urlunsplit((scheme, netloc, path, query, fragment))
 
 
+def remove_query_param(url, key):
+    """
+    Given a URL and a key/val pair, set or replace an item in the query
+    parameters of the URL, and return the new URL.
+    """
+    (scheme, netloc, path, query, fragment) = urlparse.urlsplit(url)
+    query_dict = QueryDict(query).copy()
+    query_dict.pop(key, None)
+    query = query_dict.urlencode()
+    return urlparse.urlunsplit((scheme, netloc, path, query, fragment))
+
+
+@register.simple_tag
+def get_pagination_html(pager):
+    return pager.to_html()
+
+
 # Regex for adding classes to html snippets
 class_re = re.compile(r'(?<=class=["\'])(.*)(?=["\'])')