diff --git a/wagtail/wagtailadmin/static/wagtailadmin/js/page-editor.js b/wagtail/wagtailadmin/static/wagtailadmin/js/page-editor.js
index f91355961b..cbff2c8af8 100644
--- a/wagtail/wagtailadmin/static/wagtailadmin/js/page-editor.js
+++ b/wagtail/wagtailadmin/static/wagtailadmin/js/page-editor.js
@@ -1,3 +1,15 @@
+var halloPlugins = {
+    'halloformat': {},
+    'halloheadings': {formatBlocks: ["p", "h2", "h3", "h4", "h5"]},
+    'hallolists': {},
+    'hallohr': {},
+    'halloreundo': {},
+    'hallowagtaillink': {},
+};
+function registerHalloPlugin(name, opts) {
+    halloPlugins[name] = (opts || {});
+}
+
 function makeRichTextEditable(id) {
     var input = $('#' + id);
     var richText = $('<div class="richtext"></div>').html(input.val());
@@ -19,17 +31,7 @@ function makeRichTextEditable(id) {
     richText.hallo({
         toolbar: 'halloToolbarFixed',
         toolbarcssClass: 'testy',
-        plugins: {
-            'halloformat': {},
-            'halloheadings': {formatBlocks: ["p", "h2", "h3", "h4", "h5"]},
-            'hallolists': {},
-            'hallohr': {},
-            'halloreundo': {},
-            'hallowagtailimage': {},
-            'hallowagtailembeds': {},
-            'hallowagtaillink': {},
-            'hallowagtaildoclink': {}
-        }
+        plugins: halloPlugins
     }).bind('hallomodified', function(event, data) {
         input.val(data.content);
         if (!removeStylingPending) {
diff --git a/wagtail/wagtailadmin/templates/wagtailadmin/pages/_editor_css.html b/wagtail/wagtailadmin/templates/wagtailadmin/pages/_editor_css.html
index 9c6e832e8e..2e140c89c1 100644
--- a/wagtail/wagtailadmin/templates/wagtailadmin/pages/_editor_css.html
+++ b/wagtail/wagtailadmin/templates/wagtailadmin/pages/_editor_css.html
@@ -4,11 +4,6 @@
     CSS declarations to be included on the 'create page' and 'edit page' views
 {% endcomment %}
 
-{% comment %}
-    TODO: have a mechanism for sub-apps to specify their own declarations -
-    ideally wagtailadmin shouldn't have to know anything at all about wagtailimages and friends
-{% endcomment %}
-
 {% compress css %}
     <link rel="stylesheet" href="{{ STATIC_URL }}wagtailadmin/scss/layouts/page-editor.scss" type="text/x-scss" />
     <link rel="stylesheet" href="{{ STATIC_URL }}wagtailadmin/scss/panels/rich-text.scss" type="text/x-scss" />
diff --git a/wagtail/wagtailadmin/templates/wagtailadmin/pages/_editor_js.html b/wagtail/wagtailadmin/templates/wagtailadmin/pages/_editor_js.html
index 6efaecf12d..37d600f07d 100644
--- a/wagtail/wagtailadmin/templates/wagtailadmin/pages/_editor_js.html
+++ b/wagtail/wagtailadmin/templates/wagtailadmin/pages/_editor_js.html
@@ -4,6 +4,11 @@
     Javascript declarations to be included on the 'create page' and 'edit page' views
 {% endcomment %}
 
+<script>
+    window.chooserUrls = {
+        'pageChooser': '{% url "wagtailadmin_choose_page" %}'
+    };
+</script>
 
 {% compress js %}
     <script src="{{ STATIC_URL }}wagtailadmin/js/vendor/rangy-core.js"></script>
@@ -14,21 +19,9 @@
     <script src="{{ STATIC_URL }}wagtailadmin/js/hallo-plugins/hallo-wagtail-toolbar.js"></script>
     <script src="{{ STATIC_URL }}wagtailadmin/js/hallo-plugins/hallo-wagtaillink.js"></script>
     <script src="{{ STATIC_URL }}wagtailadmin/js/hallo-plugins/hallo-hr.js"></script>
-    <script src="{{ STATIC_URL }}wagtailimages/js/hallo-plugins/hallo-wagtailimage.js"></script>
-    <script src="{{ STATIC_URL }}wagtailembeds/js/hallo-plugins/hallo-wagtailembeds.js"></script>
-    <script src="{{ STATIC_URL }}wagtaildocs/js/hallo-plugins/hallo-wagtaildoclink.js"></script>
     <script src="{{ STATIC_URL }}wagtailadmin/js/page-editor.js"></script>
 
     <script src="{{ STATIC_URL }}wagtailadmin/js/page-chooser.js"></script>
-    {% comment %}
-        TODO: use the insert_editor_js hook to inject things like image-chooser.js and hallo-wagtailimage.js
-        from their respective apps such as wagtailimages -
-        ideally wagtailadmin shouldn't have to know anything at all about wagtailimages.
-        TODO: a method of injecting these sorts of things on demand when the modal is spawned.
-    {% endcomment %}
-    <script src="{{ STATIC_URL }}wagtailimages/js/image-chooser.js"></script>
-    <script src="{{ STATIC_URL }}wagtaildocs/js/document-chooser.js"></script>
-    <script src="{{ STATIC_URL }}wagtailsnippets/js/snippet-chooser.js"></script>
     <script src="{{ STATIC_URL }}admin/js/urlify.js"></script>
 
     {% hook_output 'insert_editor_js' %}
@@ -41,19 +34,10 @@
 
 {% comment %}
     Additional js from widgets media. Allows for custom widgets in admin panel.
-    Can be used for TODO above (including image-choser.js at wagtailimages)
 {% endcomment %}
 {{ edit_handler.form.media.js }}
 
 <script>
-    window.chooserUrls = {
-        'documentChooser': '{% url "wagtaildocs_chooser" %}',
-        'imageChooser': '{% url "wagtailimages_chooser" %}',
-        'embedsChooser': '{% url "wagtailembeds_chooser" %}',
-        'pageChooser': '{% url "wagtailadmin_choose_page" %}',
-        'snippetChooser': '{% url "wagtailsnippets_choose_generic" %}'
-    };
-
     {% get_date_format_override as format_override %}
     window.overrideDateInputFormat ='{{ format_override }}';
 
diff --git a/wagtail/wagtaildocs/wagtail_hooks.py b/wagtail/wagtaildocs/wagtail_hooks.py
index 8e86221279..3ab1ad9bfa 100644
--- a/wagtail/wagtaildocs/wagtail_hooks.py
+++ b/wagtail/wagtaildocs/wagtail_hooks.py
@@ -1,5 +1,7 @@
+from django.conf import settings
 from django.conf.urls import include, url
 from django.core import urlresolvers
+from django.utils.html import format_html, format_html_join
 from django.utils.translation import ugettext_lazy as _
 
 from wagtail.wagtailadmin import hooks
@@ -21,3 +23,23 @@ def construct_main_menu(request, menu_items):
             MenuItem(_('Documents'), urlresolvers.reverse('wagtaildocs_index'), classnames='icon icon-doc-full-inverse', order=400)
         )
 hooks.register('construct_main_menu', construct_main_menu)
+
+
+def editor_js():
+    js_files = [
+        'wagtaildocs/js/hallo-plugins/hallo-wagtaildoclink.js',
+        'wagtaildocs/js/document-chooser.js',
+    ]
+    js_includes = format_html_join('\n', '<script src="{0}{1}"></script>',
+        ((settings.STATIC_URL, filename) for filename in js_files)
+    )
+    return js_includes + format_html(
+        """
+        <script>
+            window.chooserUrls.documentChooser = '{0}';
+            registerHalloPlugin('hallowagtaildoclink');
+        </script>
+        """,
+        urlresolvers.reverse('wagtaildocs_chooser')
+    )
+hooks.register('insert_editor_js', editor_js)
diff --git a/wagtail/wagtailembeds/embeds.py b/wagtail/wagtailembeds/embeds.py
index d66c5ebcc1..f8ab35f165 100644
--- a/wagtail/wagtailembeds/embeds.py
+++ b/wagtail/wagtailembeds/embeds.py
@@ -152,6 +152,17 @@ def get_embed(url, max_width=None, finder=None):
         finder = get_default_finder()
     embed_dict = finder(url, max_width)
 
+    # Make sure width and height are valid integers before inserting into database
+    try:
+        embed_dict['width'] = int(embed_dict['width'])
+    except (TypeError, ValueError):
+        embed_dict['width'] = None
+
+    try:
+        embed_dict['height'] = int(embed_dict['height'])
+    except (TypeError, ValueError):
+        embed_dict['height'] = None
+
     # Create database record
     embed, created = Embed.objects.get_or_create(
         url=url,
diff --git a/wagtail/wagtailembeds/tests.py b/wagtail/wagtailembeds/tests.py
index e3ac82d2ba..b1eefdb178 100644
--- a/wagtail/wagtailembeds/tests.py
+++ b/wagtail/wagtailembeds/tests.py
@@ -8,6 +8,20 @@ class TestEmbeds(TestCase):
     def setUp(self):
         self.hit_count = 0
 
+    def dummy_finder(self, url, max_width=None):
+        # Up hit count
+        self.hit_count += 1
+
+        # Return a pretend record
+        return {
+            'title': "Test: " + url,
+            'type': 'video',
+            'thumbnail_url': '',
+            'width': max_width if max_width else 640,
+            'height': 480,
+            'html': "<p>Blah blah blah</p>",
+        }
+
     def test_get_embed(self):
         embed = get_embed('www.test.com/1234', max_width=400, finder=self.dummy_finder)
 
@@ -31,20 +45,23 @@ class TestEmbeds(TestCase):
         embed = get_embed('www.test.com/4321', finder=self.dummy_finder)
         self.assertEqual(self.hit_count, 3)
 
-    def dummy_finder(self, url, max_width=None):
-        # Up hit count
-        self.hit_count += 1
-
-        # Return a pretend record
+    def dummy_finder_invalid_width(self, url, max_width=None):
+        # Return a record with an invalid width
         return {
             'title': "Test: " + url,
             'type': 'video',
             'thumbnail_url': '',
-            'width': max_width if max_width else 640,
+            'width': '100%',
             'height': 480,
             'html': "<p>Blah blah blah</p>",
         }
 
+    def test_invalid_width(self):
+        embed = get_embed('www.test.com/1234', max_width=400, finder=self.dummy_finder_invalid_width)
+
+        # Width must be set to None
+        self.assertEqual(embed.width, None)
+
 
 class TestChooser(TestCase):
     def setUp(self):
diff --git a/wagtail/wagtailembeds/wagtail_hooks.py b/wagtail/wagtailembeds/wagtail_hooks.py
index 0db627881d..89c5e66a55 100644
--- a/wagtail/wagtailembeds/wagtail_hooks.py
+++ b/wagtail/wagtailembeds/wagtail_hooks.py
@@ -1,4 +1,7 @@
+from django.conf import settings
 from django.conf.urls import include, url
+from django.core import urlresolvers
+from django.utils.html import format_html
 
 from wagtail.wagtailadmin import hooks
 from wagtail.wagtailembeds import urls
@@ -9,3 +12,18 @@ def register_admin_urls():
         url(r'^embeds/', include(urls)),
     ]
 hooks.register('register_admin_urls', register_admin_urls)
+
+
+def editor_js():
+    return format_html("""
+            <script src="{0}{1}"></script>
+            <script>
+                window.chooserUrls.embedsChooser = '{2}';
+                registerHalloPlugin('hallowagtailembeds');
+            </script>
+        """,
+        settings.STATIC_URL,
+        'wagtailembeds/js/hallo-plugins/hallo-wagtailembeds.js',
+        urlresolvers.reverse('wagtailembeds_chooser')
+    )
+hooks.register('insert_editor_js', editor_js)
diff --git a/wagtail/wagtailimages/wagtail_hooks.py b/wagtail/wagtailimages/wagtail_hooks.py
index f14d229043..51492d4046 100644
--- a/wagtail/wagtailimages/wagtail_hooks.py
+++ b/wagtail/wagtailimages/wagtail_hooks.py
@@ -1,5 +1,7 @@
+from django.conf import settings
 from django.conf.urls import include, url
 from django.core import urlresolvers
+from django.utils.html import format_html, format_html_join
 from django.utils.translation import ugettext_lazy as _
 
 from wagtail.wagtailadmin import hooks
@@ -21,3 +23,23 @@ def construct_main_menu(request, menu_items):
             MenuItem(_('Images'), urlresolvers.reverse('wagtailimages_index'), classnames='icon icon-image', order=300)
         )
 hooks.register('construct_main_menu', construct_main_menu)
+
+
+def editor_js():
+    js_files = [
+        'wagtailimages/js/hallo-plugins/hallo-wagtailimage.js',
+        'wagtailimages/js/image-chooser.js',
+    ]
+    js_includes = format_html_join('\n', '<script src="{0}{1}"></script>',
+        ((settings.STATIC_URL, filename) for filename in js_files)
+    )
+    return js_includes + format_html(
+        """
+        <script>
+            window.chooserUrls.imageChooser = '{0}';
+            registerHalloPlugin('hallowagtailimage');
+        </script>
+        """,
+        urlresolvers.reverse('wagtailimages_chooser')
+    )
+hooks.register('insert_editor_js', editor_js)
diff --git a/wagtail/wagtailsnippets/wagtail_hooks.py b/wagtail/wagtailsnippets/wagtail_hooks.py
index 35468f7d88..3745d1a510 100644
--- a/wagtail/wagtailsnippets/wagtail_hooks.py
+++ b/wagtail/wagtailsnippets/wagtail_hooks.py
@@ -1,5 +1,7 @@
+from django.conf import settings
 from django.conf.urls import include, url
 from django.core import urlresolvers
+from django.utils.html import format_html
 from django.utils.translation import ugettext_lazy as _
 
 from wagtail.wagtailadmin import hooks
@@ -22,3 +24,15 @@ def construct_main_menu(request, menu_items):
             MenuItem(_('Snippets'), urlresolvers.reverse('wagtailsnippets_index'), classnames='icon icon-snippet', order=500)
         )
 hooks.register('construct_main_menu', construct_main_menu)
+
+
+def editor_js():
+    return format_html("""
+            <script src="{0}{1}"></script>
+            <script>window.chooserUrls.snippetChooser = '{2}';</script>
+        """,
+        settings.STATIC_URL,
+        'wagtailsnippets/js/snippet-chooser.js',
+        urlresolvers.reverse('wagtailsnippets_choose_generic')
+    )
+hooks.register('insert_editor_js', editor_js)