Merge branch '146-display-calculated-usage'

Conflicts:
	wagtail/wagtailimages/models.py
	wagtail/wagtailimages/templates/wagtailimages/images/edit.html
	wagtail/wagtailimages/tests.py
	wagtail/wagtailimages/urls.py
	wagtail/wagtailimages/views/images.py

wagtail/tests/fixtures/test.json

@@ -562,6 +562,14 @@
         "submit_time": "2014-01-01T12:00:00.000Z"
     }
 },
+{
+    "pk": 1,
+    "model": "tests.AdvertPlacement",
+    "fields": {
+        "page": 2,
+        "advert": 1
+        }
+},
 {
     "pk": 1,
     "model": "tests.advert",
@@ -578,17 +586,6 @@
         "created_at": "2014-01-01T12:00:00.000Z"
     }
 },
-{
-    "pk": 1,
-    "model": "wagtailimages.Image",
-    "fields": {
-        "title": "test image",
-        "created_at": "2014-01-01T12:00:00.000Z",
-        "width": 0,
-        "height": 0
-    }
-},
-
 {
     "pk": 1,
     "model": "wagtailcore.pageviewrestriction",

wagtail/tests/models.py

@@ -325,9 +325,11 @@ FormPage.content_panels = [
 ]
 
 
-# Snippets
 
 # Snippets
+class AdvertPlacement(models.Model):
+    page = ParentalKey('wagtailcore.Page', related_name='advert_placements')
+    advert = models.ForeignKey('tests.Advert', related_name='+')
 
 @python_2_unicode_compatible
 class Advert(models.Model):

wagtail/wagtailadmin/templates/wagtailadmin/shared/header.html

@@ -1,3 +1,4 @@
+{% load i18n wagtailadmin_tags %}
 <header class="nice-padding {% if merged %}merged{% endif %} {% if tabbed %}tab-merged{% endif %} {% if search_form %}hasform{% endif %}">
     <div class="row">
         <div class="left">
@@ -16,6 +17,12 @@
             {% endif %}
         </div>
         <div class="right">
+            {% usage_count_enabled as uc_enabled %}
+            {% if uc_enabled and usage_object %}
+                <div class="usagecount">
+                    <a href="{{ usage_object.usage_url }}">{% blocktrans count useage_count=usage_object.get_usage.count %}Used {{ useage_count  }} time{% plural %}Used {{ useage_count }} times{% endblocktrans %}</a>
+                </div>
+            {% endif %}
             {% if add_link %}
                 <div class="addbutton">
                     <a href="{% url add_link %}" class="button bicolor icon icon-plus">{{ add_text }}</a>
@@ -23,4 +30,4 @@
             {% endif %}
         </div>
     </div>
-</header>
+</header>

wagtail/wagtailadmin/templatetags/wagtailadmin_tags.py

@@ -1,5 +1,6 @@
 from __future__ import unicode_literals
 
+from django.conf import settings
 from django import template
 from django.core import urlresolvers
 from django.utils.translation import ugettext_lazy as _
@@ -121,3 +122,13 @@ def hook_output(hook_name):
     """
     snippets = [fn() for fn in hooks.get_hooks(hook_name)]
     return ''.join(snippets)
+
+
+@register.assignment_tag
+def usage_count_enabled():
+    if hasattr(
+            settings, 'WAGTAIL_USAGE_COUNT_ENABLED'
+    ) and settings.WAGTAIL_USAGE_COUNT_ENABLED:
+        return True
+    else:
+        return False

wagtail/wagtailadmin/tests/tests.py

@@ -1,9 +1,10 @@
 from django.test import TestCase
+from django.core.urlresolvers import reverse
+from django.core import mail
+
 from wagtail.tests.utils import WagtailTestUtils
 from wagtail.wagtailcore.models import Page
 from wagtail.wagtailadmin.tasks import send_email_task
-from django.core.urlresolvers import reverse
-from django.core import mail
 
 
 class TestHome(TestCase, WagtailTestUtils):

wagtail/wagtailadmin/utils.py

@@ -0,0 +1,36 @@
+from modelcluster.fields import ParentalKey
+
+from wagtail.wagtailcore.models import Page
+
+
+def get_object_usage(obj):
+    "Returns a queryset of pages that link to a particular object"
+
+    pages = Page.objects.none()
+
+    # get all the relation objects for obj
+    relations = type(obj)._meta.get_all_related_objects(
+        include_hidden=True,
+        include_proxy_eq=True
+    )
+    for relation in relations:
+        # if the relation is between obj and a page, get the page
+        if issubclass(relation.model, Page):
+            pages |= Page.objects.filter(
+                id__in=relation.model._base_manager.filter(**{
+                    relation.field.name: obj.id
+                }).values_list('id', flat=True)
+            )
+        else:
+        # if the relation is between obj and an object that has a page as a
+        # property, return the page
+            for f in relation.model._meta.fields:
+                if isinstance(f, ParentalKey) and issubclass(f.rel.to, Page):
+                    pages |= Page.objects.filter(
+                        id__in=relation.model._base_manager.filter(
+                            **{
+                                relation.field.name: obj.id
+                            }).values_list(f.attname, flat=True)
+                    )
+
+    return pages

wagtail/wagtaildocs/admin_urls.py

@@ -11,4 +11,5 @@ urlpatterns = [
     url(r'^chooser/$', chooser.chooser, name='wagtaildocs_chooser'),
     url(r'^chooser/(\d+)/$', chooser.document_chosen, name='wagtaildocs_document_chosen'),
     url(r'^chooser/upload/$', chooser.chooser_upload, name='wagtaildocs_chooser_upload'),
+    url(r'^usage/(\d+)/$', documents.usage, name='wagtaildocs_document_usage'),
 ]

wagtail/wagtaildocs/models.py

@@ -12,6 +12,7 @@ from django.utils.translation import ugettext_lazy  as _
 from django.utils.encoding import python_2_unicode_compatible
 
 from wagtail.wagtailadmin.taggable import TagSearchable
+from wagtail.wagtailadmin.utils import get_object_usage
 from wagtail.wagtailsearch import indexed
 
 
@@ -47,6 +48,14 @@ class Document(models.Model, TagSearchable):
     def url(self):
         return reverse('wagtaildocs_serve', args=[self.id, self.filename])
 
+    def get_usage(self):
+        return get_object_usage(self)
+
+    @property
+    def usage_url(self):
+        return reverse('wagtaildocs_document_usage',
+                       args=(self.id,))
+
     def is_editable_by_user(self, user):
         if user.has_perm('wagtaildocs.change_document'):
             # user has global permission to change documents

wagtail/wagtaildocs/templates/wagtaildocs/documents/edit.html

@@ -13,7 +13,7 @@
 
 {% block content %}
     {% trans "Editing" as editing_str %}
-    {% include "wagtailadmin/shared/header.html" with title=editing_str subtitle=document.title icon="doc-full-inverse"  %}
+    {% include "wagtailadmin/shared/header.html" with title=editing_str subtitle=document.title icon="doc-full-inverse" usage_object=document %}
 
     <div class="nice-padding">
         <form action="{% url 'wagtaildocs_edit_document' document.id %}" method="POST" enctype="multipart/form-data">
@@ -30,6 +30,6 @@
             </ul>
         </form>
 
-        
+
     </div>
 {% endblock %}

wagtail/wagtaildocs/templates/wagtaildocs/documents/usage.html

@@ -0,0 +1,49 @@
+{% extends "wagtailadmin/base.html" %}
+{% load i18n %}
+{% block titletag %}{% blocktrans with title=document.title %}Usage of {{ title }}{% endblocktrans %}{% endblock %}
+{% block content %}
+    {% trans "Usage of" as usage_str %}
+    {% include "wagtailadmin/shared/header.html" with title=usage_str subtitle=document.title %}
+
+    <div class="nice-padding">
+        <table class="listing">
+            <col />
+            <col width="30%"/>
+            <col width="15%"/>
+            <col width="15%"/>
+            <thead>
+                <tr>
+                    <th class="title">{% trans "Title" %}</th>
+                    <th>{% trans "Parent" %}</th>
+                    <th>{% trans "Type" %}</th>
+                    <th>{% trans "Status" %}</th>
+                </tr>
+            </thead>
+            <tbody>
+                {% for page in used_by %}
+                    <tr>
+                        <td class="title" valign="top">
+                            <h2><a href="{% url 'wagtailadmin_pages_edit' page.id %}" title="{% trans 'Edit this page' %}">{{ page.title }}</a></h2>
+                        </td>
+                        <td>
+                            {% if page.get_parent %}
+                                <a href="{% url 'wagtailadmin_explore' page.get_parent.id %}">{{ page.get_parent.title }}</a>
+                            {% endif %}
+                        </td>
+                        <td>
+                            {{ page.content_type.model_class.get_verbose_name }}
+                        </td>
+                        <td>
+                            {% if page.live %}
+                                <a href="{{ page.url }}" target="_blank" class="status-tag {% if page.status_string != "draft" %}primary{% endif %}">{{ page.status_string }}</a>
+                            {% else %}
+                                <span class="status-tag {% if page.status_string != "draft" %}primary{% endif %}">{{ page.status_string }}</span>
+                            {% endif %}
+                        </td>
+                    </tr>
+                {% endfor %}
+            </tbody>
+        </table>
+    </div>
+    {% include "wagtailadmin/shared/pagination_nav.html" with items=used_by linkurl="-" %}
+{% endblock %}

wagtail/wagtaildocs/tests.py

@@ -5,8 +5,13 @@ from django.contrib.auth import get_user_model
 from django.contrib.auth.models import Group, Permission
 from django.core.urlresolvers import reverse
 from django.core.files.base import ContentFile
+from django.test.utils import override_settings
 
 from wagtail.tests.utils import WagtailTestUtils
+from wagtail.wagtailcore.models import Page
+
+from wagtail.tests.models import EventPage, EventPageRelatedLink
+from wagtail.wagtaildocs.models import Document
 
 from wagtail.wagtaildocs import models
 
@@ -316,3 +321,99 @@ class TestDocumentFilenameProperties(TestCase):
     def tearDown(self):
         self.document.delete()
         self.extensionless_document.delete()
+
+
+class TestUsageCount(TestCase, WagtailTestUtils):
+    fixtures = ['wagtail/tests/fixtures/test.json']
+
+    def setUp(self):
+        self.login()
+
+    @override_settings(WAGTAIL_USAGE_COUNT_ENABLED=True)
+    def test_unused_document_usage_count(self):
+        doc = Document.objects.get(id=1)
+        self.assertEqual(doc.get_usage().count(), 0)
+
+    @override_settings(WAGTAIL_USAGE_COUNT_ENABLED=True)
+    def test_used_document_usage_count(self):
+        doc = Document.objects.get(id=1)
+        page = EventPage.objects.get(id=4)
+        event_page_related_link = EventPageRelatedLink()
+        event_page_related_link.page = page
+        event_page_related_link.link_document = doc
+        event_page_related_link.save()
+        self.assertEqual(doc.get_usage().count(), 1)
+
+    def test_usage_count_does_not_appear(self):
+        doc = Document.objects.get(id=1)
+        page = EventPage.objects.get(id=4)
+        event_page_related_link = EventPageRelatedLink()
+        event_page_related_link.page = page
+        event_page_related_link.link_document = doc
+        event_page_related_link.save()
+        response = self.client.get(reverse('wagtaildocs_edit_document',
+                                           args=(1,)))
+        self.assertNotContains(response, 'Used 1 time')
+
+    @override_settings(WAGTAIL_USAGE_COUNT_ENABLED=True)
+    def test_usage_count_appears(self):
+        doc = Document.objects.get(id=1)
+        page = EventPage.objects.get(id=4)
+        event_page_related_link = EventPageRelatedLink()
+        event_page_related_link.page = page
+        event_page_related_link.link_document = doc
+        event_page_related_link.save()
+        response = self.client.get(reverse('wagtaildocs_edit_document',
+                                           args=(1,)))
+        self.assertContains(response, 'Used 1 time')
+
+    @override_settings(WAGTAIL_USAGE_COUNT_ENABLED=True)
+    def test_usage_count_zero_appears(self):
+        response = self.client.get(reverse('wagtaildocs_edit_document',
+                                           args=(1,)))
+        self.assertContains(response, 'Used 0 times')
+
+
+class TestGetUsage(TestCase, WagtailTestUtils):
+    fixtures = ['wagtail/tests/fixtures/test.json']
+
+    def setUp(self):
+        self.login()
+
+    def test_document_get_usage_not_enabled(self):
+        doc = Document.objects.get(id=1)
+        self.assertEqual(list(doc.get_usage()), [])
+
+    @override_settings(WAGTAIL_USAGE_COUNT_ENABLED=True)
+    def test_unused_document_get_usage(self):
+        doc = Document.objects.get(id=1)
+        self.assertEqual(list(doc.get_usage()), [])
+
+    @override_settings(WAGTAIL_USAGE_COUNT_ENABLED=True)
+    def test_used_document_get_usage(self):
+        doc = Document.objects.get(id=1)
+        page = EventPage.objects.get(id=4)
+        event_page_related_link = EventPageRelatedLink()
+        event_page_related_link.page = page
+        event_page_related_link.link_document = doc
+        event_page_related_link.save()
+        self.assertTrue(issubclass(Page, type(doc.get_usage()[0])))
+
+    @override_settings(WAGTAIL_USAGE_COUNT_ENABLED=True)
+    def test_usage_page(self):
+        doc = Document.objects.get(id=1)
+        page = EventPage.objects.get(id=4)
+        event_page_related_link = EventPageRelatedLink()
+        event_page_related_link.page = page
+        event_page_related_link.link_document = doc
+        event_page_related_link.save()
+        response = self.client.get(reverse('wagtaildocs_document_usage',
+                                           args=(1,)))
+        self.assertContains(response, 'Christmas')
+
+    @override_settings(WAGTAIL_USAGE_COUNT_ENABLED=True)
+    def test_usage_page_no_usage(self):
+        response = self.client.get(reverse('wagtaildocs_document_usage',
+                                           args=(1,)))
+        # There's no usage so there should be no table rows
+        self.assertRegex(response.content, b'<tbody>(\s|\n)*</tbody>')

wagtail/wagtaildocs/views/documents.py

@@ -5,6 +5,7 @@ from django.contrib.auth.decorators import permission_required
 from django.core.exceptions import PermissionDenied
 from django.utils.translation import ugettext as _
 from django.views.decorators.vary import vary_on_headers
+from django.core.urlresolvers import reverse
 
 from wagtail.wagtailadmin.forms import SearchForm
 
@@ -120,7 +121,7 @@ def edit(request, document_id):
 
     return render(request, "wagtaildocs/documents/edit.html", {
         'document': doc,
-        'form': form,
+        'form': form
     })
 
 
@@ -139,3 +140,24 @@ def delete(request, document_id):
     return render(request, "wagtaildocs/documents/confirm_delete.html", {
         'document': doc,
     })
+
+
+@permission_required('wagtailadmin.access_admin')
+def usage(request, document_id):
+    doc = get_object_or_404(Document, id=document_id)
+
+    # Pagination
+    p = request.GET.get('p', 1)
+    paginator = Paginator(doc.get_usage(), 20)
+
+    try:
+        used_by = paginator.page(p)
+    except PageNotAnInteger:
+        used_by = paginator.page(1)
+    except EmptyPage:
+        used_by = paginator.page(paginator.num_pages)
+
+    return render(request, "wagtaildocs/documents/usage.html", {
+        'document': doc,
+        'used_by': used_by
+    })

wagtail/wagtailimages/admin_urls.py

@@ -10,6 +10,7 @@ urlpatterns = [
     url(r'^(\d+)/generate_url/$', images.url_generator, name='wagtailimages_url_generator'),
     url(r'^(\d+)/generate_url/(.*)/$', images.generate_url, name='wagtailimages_generate_url'),
     url(r'^add/$', images.add, name='wagtailimages_add_image'),
+    url(r'^usage/(\d+)/$', images.usage, name='wagtailimages_image_usage'),
 
     url(r'^multiple/add/$', multiple.add, name='wagtailimages_add_multiple'),
     url(r'^multiple/(\d+)/$', multiple.edit, name='wagtailimages_edit_multiple'),

wagtail/wagtailimages/models.py

@@ -16,6 +16,7 @@ from django.conf import settings
 from django.utils.translation import ugettext_lazy  as _
 from django.utils.encoding import python_2_unicode_compatible
 from django.utils.functional import cached_property
+from django.core.urlresolvers import reverse
 
 from unidecode import unidecode
 
@@ -25,6 +26,7 @@ from wagtail.wagtailsearch import indexed
 from wagtail.wagtailimages.utils.validators import validate_image_format
 from wagtail.wagtailimages.utils.focal_point import FocalPoint
 from wagtail.wagtailimages.utils.feature_detection import FeatureDetector, opencv_available
+from wagtail.wagtailadmin.utils import get_object_usage
 
 
 @python_2_unicode_compatible
@@ -57,6 +59,14 @@ class AbstractImage(models.Model, TagSearchable):
     focal_point_width = models.PositiveIntegerField(null=True, editable=False)
     focal_point_height = models.PositiveIntegerField(null=True, editable=False)
 
+    def get_usage(self):
+        return get_object_usage(self)
+
+    @property
+    def usage_url(self):
+        return reverse('wagtailimages_image_usage',
+                       args=(self.id,))
+
     search_fields = TagSearchable.search_fields + (
         indexed.FilterField('uploaded_by_user'),
     )

wagtail/wagtailimages/templates/wagtailimages/images/edit.html

@@ -13,10 +13,10 @@
 
 {% block content %}
     {% trans "Editing" as editing_str %}
-    {% include "wagtailadmin/shared/header.html" with title=editing_str subtitle=image.title icon="image" %}
-    
+    {% include "wagtailadmin/shared/header.html" with title=editing_str subtitle=image.title icon="image" usage_object=image %}
+
     <div class="row row-flush nice-padding">
-       
+
         <div class="col7">
             <form action="{% url 'wagtailimages_edit_image' image.id %}" method="POST" enctype="multipart/form-data">
                 {% csrf_token %}

wagtail/wagtailimages/templates/wagtailimages/images/usage.html

@@ -0,0 +1,49 @@
+{% extends "wagtailadmin/base.html" %}
+{% load i18n %}
+{% block titletag %}{% blocktrans with title=image.title %}Usage of {{ title }}{% endblocktrans %}{% endblock %}
+{% block content %}
+    {% trans "Usage of" as usage_str %}
+    {% include "wagtailadmin/shared/header.html" with title=usage_str subtitle=image.title %}
+
+    <div class="nice-padding">
+        <table class="listing">
+            <col />
+            <col width="30%"/>
+            <col width="15%"/>
+            <col width="15%"/>
+            <thead>
+                <tr>
+                    <th class="title">{% trans "Title" %}</th>
+                    <th>{% trans "Parent" %}</th>
+                    <th>{% trans "Type" %}</th>
+                    <th>{% trans "Status" %}</th>
+                </tr>
+            </thead>
+            <tbody>
+                {% for page in used_by %}
+                    <tr>
+                        <td class="title" valign="top">
+                            <h2><a href="{% url 'wagtailadmin_pages_edit' page.id %}" title="{% trans 'Edit this page' %}">{{ page.title }}</a></h2>
+                        </td>
+                        <td>
+                            {% if page.get_parent %}
+                                <a href="{% url 'wagtailadmin_explore' page.get_parent.id %}">{{ page.get_parent.title }}</a>
+                            {% endif %}
+                        </td>
+                        <td>
+                            {{ page.content_type.model_class.get_verbose_name }}
+                        </td>
+                        <td>
+                            {% if page.live %}
+                                <a href="{{ page.url }}" target="_blank" class="status-tag {% if page.status_string != "draft" %}primary{% endif %}">{{ page.status_string }}</a>
+                            {% else %}
+                                <span class="status-tag {% if page.status_string != "draft" %}primary{% endif %}">{{ page.status_string }}</span>
+                            {% endif %}
+                        </td>
+                    </tr>
+                {% endfor %}
+            </tbody>
+        </table>
+    </div>
+    {% include "wagtailadmin/shared/pagination_nav.html" with items=used_by linkurl="-" %}
+{% endblock %}

wagtail/wagtailimages/tests.py

@@ -8,6 +8,7 @@ from django.utils import six
 from django.utils.http import urlquote
 from django.utils import timezone
 from django.test import TestCase
+from django.test.utils import override_settings
 from django import template
 from django.contrib.auth import get_user_model
 from django.contrib.auth.models import Group, Permission
@@ -27,6 +28,8 @@ from wagtail.wagtailimages.backends.pillow import PillowBackend
 from wagtail.wagtailimages.utils.crop import crop_to_point, CropBox
 from wagtail.wagtailimages.utils.focal_point import FocalPoint
 from wagtail.wagtailimages.utils.crypto import generate_signature, verify_signature
+from wagtail.tests.models import EventPage, EventPageCarouselItem
+from wagtail.wagtailcore.models import Page
 
 
 def get_test_image_file():
@@ -484,6 +487,55 @@ class TestFormat(TestCase):
         self.assertEqual(result, self.format)
 
 
+class TestUsageCount(TestCase):
+    fixtures = ['wagtail/tests/fixtures/test.json']
+
+    def setUp(self):
+        self.image = Image.objects.create(
+            title="Test image",
+            file=get_test_image_file(),
+        )
+
+    @override_settings(WAGTAIL_USAGE_COUNT_ENABLED=True)
+    def test_unused_image_usage_count(self):
+        self.assertEqual(self.image.get_usage().count(), 0)
+
+    @override_settings(WAGTAIL_USAGE_COUNT_ENABLED=True)
+    def test_used_image_document_usage_count(self):
+        page = EventPage.objects.get(id=4)
+        event_page_carousel_item = EventPageCarouselItem()
+        event_page_carousel_item.page = page
+        event_page_carousel_item.image = self.image
+        event_page_carousel_item.save()
+        self.assertEqual(self.image.get_usage().count(), 1)
+
+
+class TestGetUsage(TestCase):
+    fixtures = ['wagtail/tests/fixtures/test.json']
+
+    def setUp(self):
+        self.image = Image.objects.create(
+            title="Test image",
+            file=get_test_image_file(),
+        )
+
+    def test_image_get_usage_not_enabled(self):
+        self.assertEqual(list(self.image.get_usage()), [])
+
+    @override_settings(WAGTAIL_USAGE_COUNT_ENABLED=True)
+    def test_unused_image_get_usage(self):
+        self.assertEqual(list(self.image.get_usage()), [])
+
+    @override_settings(WAGTAIL_USAGE_COUNT_ENABLED=True)
+    def test_used_image_document_get_usage(self):
+        page = EventPage.objects.get(id=4)
+        event_page_carousel_item = EventPageCarouselItem()
+        event_page_carousel_item.page = page
+        event_page_carousel_item.image = self.image
+        event_page_carousel_item.save()
+        self.assertTrue(issubclass(Page, type(self.image.get_usage()[0])))
+
+
 class TestMultipleImageUploader(TestCase, WagtailTestUtils):
     """
     This tests the multiple image upload views located in wagtailimages/views/multiple.py

wagtail/wagtailimages/views/images.py

@@ -38,7 +38,6 @@ def index(request):
         if form.is_valid():
             query_string = form.cleaned_data['q']
 
-            is_searching = True
             if not request.user.has_perm('wagtailimages.change_image'):
                 # restrict to the user's own images
                 images = Image.search(query_string, filters={'uploaded_by_user_id': request.user.id})
@@ -214,3 +213,24 @@ def add(request):
     return render(request, "wagtailimages/images/add.html", {
         'form': form,
     })
+
+
+@permission_required('wagtailadmin.access_admin')
+def usage(request, image_id):
+    image = get_object_or_404(get_image_model(), id=image_id)
+
+    # Pagination
+    p = request.GET.get('p', 1)
+    paginator = Paginator(image.get_usage(), 20)
+
+    try:
+        used_by = paginator.page(p)
+    except PageNotAnInteger:
+        used_by = paginator.page(1)
+    except EmptyPage:
+        used_by = paginator.page(paginator.num_pages)
+
+    return render(request, "wagtailimages/images/usage.html", {
+        'image': image,
+        'used_by': used_by
+    })

wagtail/wagtailsnippets/models.py

@@ -1,4 +1,7 @@
 from django.contrib.contenttypes.models import ContentType
+from django.core.urlresolvers import reverse
+
+from wagtail.wagtailadmin.utils import get_object_usage
 
 SNIPPET_MODELS = []
 
@@ -18,5 +21,15 @@ def get_snippet_content_types():
 
 def register_snippet(model):
     if model not in SNIPPET_MODELS:
+        model.get_usage = get_object_usage
+        model.usage_url = get_snippet_usage_url
         SNIPPET_MODELS.append(model)
         SNIPPET_MODELS.sort(key=lambda x: x._meta.verbose_name)
+
+
+def get_snippet_usage_url(self):
+    content_type = ContentType.objects.get_for_model(self)
+    return reverse('wagtailsnippets_usage',
+                   args=(content_type.app_label,
+                         content_type.model,
+                         self.id,))

wagtail/wagtailsnippets/templates/wagtailsnippets/snippets/edit.html

@@ -4,12 +4,12 @@
 {% block bodyclass %}menu-snippets{% endblock %}
 {% block content %}
     {% trans "Editing" as editing_str %}
-    {% include "wagtailadmin/shared/header.html" with title=editing_str subtitle=instance icon="snippet" %}
+    {% include "wagtailadmin/shared/header.html" with title=editing_str subtitle=instance icon="snippet" usage_object=instance %}
 
     <form action="{% url 'wagtailsnippets_edit' content_type.app_label content_type.model instance.id %}" method="POST">
         {% csrf_token %}
         {{ edit_handler.render_form_content }}
-    
+
         <footer>
             <ul>
                 <li class="actions">

wagtail/wagtailsnippets/templates/wagtailsnippets/snippets/usage.html

@@ -0,0 +1,49 @@
+{% extends "wagtailadmin/base.html" %}
+{% load i18n %}
+{% block titletag %}{% blocktrans with title=instance %}Usage of {{ title }}{% endblocktrans %}{% endblock %}
+{% block content %}
+    {% trans "Usage of" as usage_str %}
+    {% include "wagtailadmin/shared/header.html" with title=usage_str subtitle=instance %}
+
+    <div class="nice-padding">
+        <table class="listing">
+            <col />
+            <col width="30%"/>
+            <col width="15%"/>
+            <col width="15%"/>
+            <thead>
+                <tr>
+                    <th class="title">{% trans "Title" %}</th>
+                    <th>{% trans "Parent" %}</th>
+                    <th>{% trans "Type" %}</th>
+                    <th>{% trans "Status" %}</th>
+                </tr>
+            </thead>
+            <tbody>
+                {% for page in used_by %}
+                    <tr>
+                        <td class="title" valign="top">
+                            <h2><a href="{% url 'wagtailadmin_pages_edit' page.id %}" title="{% trans 'Edit this page' %}">{{ page.title }}</a></h2>
+                        </td>
+                        <td>
+                            {% if page.get_parent %}
+                                <a href="{% url 'wagtailadmin_explore' page.get_parent.id %}">{{ page.get_parent.title }}</a>
+                            {% endif %}
+                        </td>
+                        <td>
+                            {{ page.content_type.model_class.get_verbose_name }}
+                        </td>
+                        <td>
+                            {% if page.live %}
+                                <a href="{{ page.url }}" target="_blank" class="status-tag {% if page.status_string != "draft" %}primary{% endif %}">{{ page.status_string }}</a>
+                            {% else %}
+                                <span class="status-tag {% if page.status_string != "draft" %}primary{% endif %}">{{ page.status_string }}</span>
+                            {% endif %}
+                        </td>
+                    </tr>
+                {% endfor %}
+            </tbody>
+        </table>
+    </div>
+    {% include "wagtailadmin/shared/pagination_nav.html" with items=used_by linkurl="-"%}
+{% endblock %}

wagtail/wagtailsnippets/tests.py

@@ -2,6 +2,7 @@ from django.test import TestCase
 from django.core.urlresolvers import reverse
 
 from wagtail.tests.utils import WagtailTestUtils
+from django.test.utils import override_settings
 from wagtail.tests.models import Advert, AlphaSnippet, ZuluSnippet
 from wagtail.wagtailsnippets.models import register_snippet, SNIPPET_MODELS
 
@@ -9,6 +10,7 @@ from wagtail.wagtailsnippets.views.snippets import (
     get_snippet_edit_handler
 )
 from wagtail.wagtailsnippets.edit_handlers import SnippetChooserPanel
+from wagtail.wagtailcore.models import Page
 
 
 class TestSnippetIndexView(TestCase, WagtailTestUtils):
@@ -185,3 +187,21 @@ class TestSnippetOrdering(TestCase):
         # may get registered elsewhere during test
         self.assertLess(SNIPPET_MODELS.index(AlphaSnippet),
                         SNIPPET_MODELS.index(ZuluSnippet))
+
+
+class TestUsageCount(TestCase):
+    fixtures = ['wagtail/tests/fixtures/test.json']
+
+    @override_settings(WAGTAIL_USAGE_COUNT_ENABLED=True)
+    def test_snippet_usage_count(self):
+        advert = Advert.objects.get(id=1)
+        self.assertEqual(advert.get_usage().count(), 1)
+
+
+class TestUsedBy(TestCase):
+    fixtures = ['wagtail/tests/fixtures/test.json']
+
+    @override_settings(WAGTAIL_USAGE_COUNT_ENABLED=True)
+    def test_snippet_used_by(self):
+        advert = Advert.objects.get(id=1)
+        self.assertEqual(type(advert.get_usage()[0]), Page)

wagtail/wagtailsnippets/urls.py

@@ -13,4 +13,5 @@ urlpatterns = [
     url(r'^(\w+)/(\w+)/new/$', snippets.create, name='wagtailsnippets_create'),
     url(r'^(\w+)/(\w+)/(\d+)/$', snippets.edit, name='wagtailsnippets_edit'),
     url(r'^(\w+)/(\w+)/(\d+)/delete/$', snippets.delete, name='wagtailsnippets_delete'),
+    url(r'^(\w+)/(\w+)/(\d+)/usage/$', snippets.usage, name='wagtailsnippets_usage'),
 ]

wagtail/wagtailsnippets/views/snippets.py

@@ -7,6 +7,8 @@ from django.contrib import messages
 from django.contrib.auth.decorators import permission_required
 from django.core.exceptions import PermissionDenied
 from django.utils.translation import ugettext as _
+from django.core.urlresolvers import reverse
+from django.core.paginator import Paginator, EmptyPage, PageNotAnInteger
 
 from wagtail.wagtailadmin.edit_handlers import ObjectList, extract_panel_definitions_from_model_class
 
@@ -182,7 +184,7 @@ def edit(request, content_type_app_name, content_type_model_name, id):
         'content_type': content_type,
         'snippet_type_name': snippet_type_name,
         'instance': instance,
-        'edit_handler': edit_handler,
+        'edit_handler': edit_handler
     })
 
 
@@ -213,3 +215,26 @@ def delete(request, content_type_app_name, content_type_model_name, id):
         'snippet_type_name': snippet_type_name,
         'instance': instance,
     })
+
+
+@permission_required('wagtailadmin.access_admin')
+def usage(request, content_type_app_name, content_type_model_name, id):
+    content_type = get_content_type_from_url_params(content_type_app_name, content_type_model_name)
+    model = content_type.model_class()
+    instance = get_object_or_404(model, id=id)
+
+    # Pagination
+    p = request.GET.get('p', 1)
+    paginator = Paginator(instance.get_usage(), 20)
+
+    try:
+        used_by = paginator.page(p)
+    except PageNotAnInteger:
+        used_by = paginator.page(1)
+    except EmptyPage:
+        used_by = paginator.page(paginator.num_pages)
+
+    return render(request, "wagtailsnippets/snippets/usage.html", {
+        'instance': instance,
+        'used_by': used_by
+    })