Add realm-level settings to control inline image and url preview.

This gives users more control in case they don't want previews,
especially for the "previews of linked websites" feature.

Fixes: #2640.

static/js/admin.js

@@ -381,6 +381,10 @@ function _setup_page() {
         realm_restricted_to_domain: page_params.realm_restricted_to_domain,
         realm_invite_required: page_params.realm_invite_required,
         realm_invite_by_admins_only: page_params.realm_invite_by_admins_only,
+        realm_inline_image_preview: page_params.realm_inline_image_preview,
+        server_inline_image_preview: page_params.server_inline_image_preview,
+        realm_inline_url_embed_preview: page_params.realm_inline_url_embed_preview,
+        server_inline_url_embed_preview: page_params.server_inline_url_embed_preview,
         realm_authentication_methods: page_params.realm_authentication_methods,
         realm_create_stream_by_admins_only: page_params.realm_create_stream_by_admins_only,
         realm_name_changes_disabled: page_params.realm_name_changes_disabled,
@@ -623,6 +627,8 @@ function _setup_page() {
         var restricted_to_domain_status = $("#admin-realm-restricted-to-domain-status").expectOne();
         var invite_required_status = $("#admin-realm-invite-required-status").expectOne();
         var invite_by_admins_only_status = $("#admin-realm-invite-by-admins-only-status").expectOne();
+        var inline_image_preview_status = $("#admin-realm-inline-image-preview-status").expectOne();
+        var inline_url_embed_preview_status = $("#admin-realm-inline-url-embed-preview-status").expectOne();
         var authentication_methods_status = $("#admin-realm-authentication-methods-status").expectOne();
         var create_stream_by_admins_only_status = $("#admin-realm-create-stream-by-admins-only-status").expectOne();
         var name_changes_disabled_status = $("#admin-realm-name-changes-disabled-status").expectOne();
@@ -636,6 +642,8 @@ function _setup_page() {
         restricted_to_domain_status.hide();
         invite_required_status.hide();
         invite_by_admins_only_status.hide();
+        inline_image_preview_status.hide();
+        inline_url_embed_preview_status.hide();
         authentication_methods_status.hide();
         create_stream_by_admins_only_status.hide();
         name_changes_disabled_status.hide();
@@ -653,6 +661,8 @@ function _setup_page() {
         var new_restricted = $("#id_realm_restricted_to_domain").prop("checked");
         var new_invite = $("#id_realm_invite_required").prop("checked");
         var new_invite_by_admins_only = $("#id_realm_invite_by_admins_only").prop("checked");
+        var new_inline_image_preview = $("#id_realm_inline_image_preview").prop("checked");
+        var new_inline_url_embed_preview = $("#id_realm_inline_url_embed_preview").prop("checked");
         var new_create_stream_by_admins_only = $("#id_realm_create_stream_by_admins_only").prop("checked");
         var new_name_changes_disabled = $("#id_realm_name_changes_disabled").prop("checked");
         var new_email_changes_disabled = $("#id_realm_email_changes_disabled").prop("checked");
@@ -685,6 +695,8 @@ function _setup_page() {
             restricted_to_domain: JSON.stringify(new_restricted),
             invite_required: JSON.stringify(new_invite),
             invite_by_admins_only: JSON.stringify(new_invite_by_admins_only),
+            inline_image_preview: JSON.stringify(new_inline_image_preview),
+            inline_url_embed_preview: JSON.stringify(new_inline_url_embed_preview),
             authentication_methods: JSON.stringify(new_auth_methods),
             create_stream_by_admins_only: JSON.stringify(new_create_stream_by_admins_only),
             name_changes_disabled: JSON.stringify(new_name_changes_disabled),
@@ -728,6 +740,20 @@ function _setup_page() {
                         ui_report.success(i18n.t("Any user may now invite new users!"), invite_by_admins_only_status);
                     }
                 }
+                if (response_data.inline_image_preview !== undefined) {
+                    if (response_data.inline_image_preview) {
+                        ui.report_success(i18n.t("Previews of uploaded and linked images will be shown!"), inline_image_preview_status);
+                    } else {
+                        ui.report_success(i18n.t("Previews of uploaded and linked images will not be shown!"), inline_image_preview_status);
+                    }
+                }
+                if (response_data.inline_url_embed_preview !== undefined) {
+                    if (response_data.inline_url_embed_preview) {
+                        ui.report_success(i18n.t("Previews for linked websites will be shown!"), inline_url_embed_preview_status);
+                    } else {
+                        ui.report_success(i18n.t("Previews for linked websites will not be shown!"), inline_url_embed_preview_status);
+                    }
+                }
                 if (response_data.create_stream_by_admins_only !== undefined) {
                     if (response_data.create_stream_by_admins_only) {
                         ui_report.success(i18n.t("Only administrators may now create new streams!"), create_stream_by_admins_only_status);

static/js/server_events.js

@@ -62,6 +62,10 @@ function dispatch_normal_event(event) {
             page_params.realm_invite_required = event.value;
         } else if (event.op === 'update' && event.property === 'invite_by_admins_only') {
             page_params.realm_invite_by_admins_only = event.value;
+        } else if (event.op === 'update' && event.property === 'inline_image_preview') {
+            page_params.realm_inline_image_preview = event.value;
+        } else if (event.op === 'update' && event.property === 'inline_url_embed_preview') {
+            page_params.realm_inline_url_embed_preview = event.value;
         } else if (event.op === 'update' && event.property === 'create_stream_by_admins_only') {
             page_params.realm_create_stream_by_admins_only = event.value;
             if (!page_params.is_admin) {

static/templates/settings/organization-settings-admin.handlebars

@@ -7,6 +7,8 @@
     <div class="alert" id="admin-realm-restricted-to-domain-status"></div>
     <div class="alert" id="admin-realm-invite-required-status"></div>
     <div class="alert" id="admin-realm-invite-by-admins-only-status"></div>
+    <div class="alert" id="admin-realm-inline-image-preview-status"></div>
+    <div class="alert" id="admin-realm-inline-url-embed-preview-status"></div>
     <div class="alert" id="admin-realm-create-stream-by-admins-only-status"></div>
     <div class="alert" id="admin-realm-add-emoji-by-admins-only-status"></div>
     <div class="alert" id="admin-realm-message-editing-status"></div>
@@ -55,6 +57,30 @@
         {{t "Only admins may invite" }}
       </label>
     </div>
+    {{#if server_inline_image_preview}}
+    <div class="input-group">
+      <input type="checkbox" class="inline-block" id="id_realm_inline_image_preview" name="realm_inline_image_preview"
+        {{#if realm_inline_image_preview}}checked="checked"{{/if}} />
+      <label for="id_realm_inline_image_preview"
+        id="id_realm_inline_image_preview_label"
+        title="{{t 'If checked, image previews will be shown.' }}"
+        class="inline-block" style="width:initial">
+        {{t "Show previews of uploaded and linked images" }}
+      </label>
+    </div>
+    {{/if}}
+    {{#if server_inline_url_embed_preview}}
+    <div class="input-group">
+      <input type="checkbox" class="inline-block" id="id_realm_inline_url_embed_preview" name="realm_inline_url_embed_preview"
+        {{#if realm_inline_url_embed_preview}}checked="checked"{{/if}} />
+      <label for="id_realm_inline_url_embed_preview"
+        id="id_realm_inline_url_embed_preview_label"
+        title="{{t 'If checked, previews of linked websites will be shown.' }}"
+        class="inline-block">
+        {{t "Show previews of linked websites" }}
+      </label>
+    </div>
+    {{/if}}
     <div class="input-group">
       <input type="checkbox" class="inline-block" id="id_realm_create_stream_by_admins_only"
              name="realm_create_stream_by_admins_only"

zerver/lib/actions.py

@@ -12,7 +12,8 @@ from django.core import validators
 from analytics.lib.counts import COUNT_STATS, do_increment_logging_stat
 from zerver.lib.bugdown import (
     BugdownRenderingException,
-    version as bugdown_version
+    version as bugdown_version,
+    url_embed_preview_enabled_for_realm
 )
 from zerver.lib.cache import (
     to_dict_cache_key,
@@ -479,6 +480,30 @@ def do_set_realm_invite_by_admins_only(realm, invite_by_admins_only):
     )
     send_event(event, active_user_ids(realm))
 
+def do_set_realm_inline_image_preview(realm, inline_image_preview):
+    # type: (Realm, bool) -> None
+    realm.inline_image_preview = inline_image_preview
+    realm.save(update_fields=['inline_image_preview'])
+    event = dict(
+        type="realm",
+        op="update",
+        property='inline_image_preview',
+        value=inline_image_preview,
+    )
+    send_event(event, active_user_ids(realm))
+
+def do_set_realm_inline_url_embed_preview(realm, inline_url_embed_preview):
+    # type: (Realm, bool) -> None
+    realm.inline_url_embed_preview = inline_url_embed_preview
+    realm.save(update_fields=['inline_url_embed_preview'])
+    event = dict(
+        type="realm",
+        op="update",
+        property='inline_url_embed_preview',
+        value=inline_url_embed_preview,
+    )
+    send_event(event, active_user_ids(realm))
+
 def do_set_realm_authentication_methods(realm, authentication_methods):
     # type: (Realm, Dict[str, bool]) -> None
     for key, value in list(authentication_methods.items()):
@@ -924,7 +949,7 @@ def do_send_messages(messages_maybe_none):
             event['sender_queue_id'] = message['sender_queue_id']
         send_event(event, users)
 
-        if settings.INLINE_URL_EMBED_PREVIEW and links_for_embed:
+        if url_embed_preview_enabled_for_realm(message['message']) and links_for_embed:
             event_data = {
                 'message_id': message['message'].id,
                 'message_content': message['message'].content,

zerver/lib/bugdown/__init__.py

@@ -63,6 +63,32 @@ if False:
 class BugdownRenderingException(Exception):
     pass
 
+def url_embed_preview_enabled_for_realm(message):
+    # type: (Message) -> bool
+    if message is not None:
+        realm = message.get_realm()
+    else:
+        realm = None
+
+    if not settings.INLINE_URL_EMBED_PREVIEW:
+        return False
+    if realm is None:
+        return True
+    return realm.inline_url_embed_preview
+
+def image_preview_enabled_for_realm():
+    # type: () -> bool
+    global current_message
+    if current_message is not None:
+        realm = current_message.get_realm()
+    else:
+        realm = None
+    if not settings.INLINE_IMAGE_PREVIEW:
+        return False
+    if realm is None:
+        return True
+    return realm.inline_image_preview
+
 def unescape(s):
     # type: (Text) -> (Text)
     if six.PY2:
@@ -327,7 +353,7 @@ class InlineInterestingLinkProcessor(markdown.treeprocessors.Treeprocessor):
 
     def is_image(self, url):
         # type: (Text) -> bool
-        if not settings.INLINE_IMAGE_PREVIEW:
+        if not image_preview_enabled_for_realm():
             return False
         parsed_url = urllib.parse.urlparse(url)
         # List from http://support.google.com/chromeos/bin/answer.py?hl=en&answer=183093
@@ -384,7 +410,7 @@ class InlineInterestingLinkProcessor(markdown.treeprocessors.Treeprocessor):
 
     def youtube_id(self, url):
         # type: (Text) -> Optional[Text]
-        if not settings.INLINE_IMAGE_PREVIEW:
+        if not image_preview_enabled_for_realm():
             return None
         # Youtube video id extraction regular expression from http://pastebin.com/KyKAFv1s
         # If it matches, match.group(2) is the video id.
@@ -620,7 +646,7 @@ class InlineInterestingLinkProcessor(markdown.treeprocessors.Treeprocessor):
             if db_data and db_data['sent_by_bot']:
                 continue
 
-            if current_message is None or not settings.INLINE_URL_EMBED_PREVIEW:
+            if current_message is None or not url_embed_preview_enabled_for_realm(current_message):
                 continue
             try:
                 extracted_data = link_preview.link_embed_data_from_cache(url)

zerver/lib/events.py

@@ -97,6 +97,8 @@ def fetch_initial_state_data(user_profile, event_types, queue_id,
         state['realm_restricted_to_domain'] = user_profile.realm.restricted_to_domain
         state['realm_invite_required'] = user_profile.realm.invite_required
         state['realm_invite_by_admins_only'] = user_profile.realm.invite_by_admins_only
+        state['realm_inline_image_preview'] = user_profile.realm.inline_image_preview
+        state['realm_inline_url_embed_preview'] = user_profile.realm.inline_url_embed_preview
         state['realm_authentication_methods'] = user_profile.realm.authentication_methods_dict()
         state['realm_create_stream_by_admins_only'] = user_profile.realm.create_stream_by_admins_only
         state['realm_add_emoji_by_admins_only'] = user_profile.realm.add_emoji_by_admins_only

zerver/migrations/0065_realm_inline_image_preview.py

@@ -0,0 +1,20 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.10.5 on 2017-03-21 15:56
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('zerver', '0064_sync_uploads_filesize_with_db'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='realm',
+            name='inline_image_preview',
+            field=models.BooleanField(default=True),
+        ),
+    ]

zerver/migrations/0066_realm_inline_url_embed_preview.py

@@ -0,0 +1,20 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.10.5 on 2017-03-21 15:58
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('zerver', '0065_realm_inline_image_preview'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='realm',
+            name='inline_url_embed_preview',
+            field=models.BooleanField(default=True),
+        ),
+    ]

zerver/models.py

@@ -116,6 +116,8 @@ class Realm(ModelReprMixin, models.Model):
     restricted_to_domain = models.BooleanField(default=False) # type: bool
     invite_required = models.BooleanField(default=True) # type: bool
     invite_by_admins_only = models.BooleanField(default=False) # type: bool
+    inline_image_preview = models.BooleanField(default=True) # type: bool
+    inline_url_embed_preview = models.BooleanField(default=True) # type: bool
     create_stream_by_admins_only = models.BooleanField(default=False) # type: bool
     add_emoji_by_admins_only = models.BooleanField(default=False) # type: bool
     mandatory_topics = models.BooleanField(default=False) # type: bool

zerver/tests/test_bugdown.py

@@ -2,7 +2,7 @@
 from __future__ import print_function
 from __future__ import absolute_import
 from django.conf import settings
-from django.test import TestCase
+from django.test import TestCase, override_settings
 
 from zerver.lib import bugdown
 from zerver.lib.actions import (
@@ -37,6 +37,7 @@ from zerver.models import (
     Recipient,
 )
 
+import copy
 import mock
 import os
 import ujson
@@ -229,6 +230,65 @@ class BugdownTest(TestCase):
 
         self.assertEqual(converted, '<p>Check out the debate: <a href="http://www.youtube.com/watch?v=hx1mjT73xYE" target="_blank" title="http://www.youtube.com/watch?v=hx1mjT73xYE">http://www.youtube.com/watch?v=hx1mjT73xYE</a></p>\n<div class="youtube-video message_inline_image"><a data-id="hx1mjT73xYE" href="http://www.youtube.com/watch?v=hx1mjT73xYE" target="_blank" title="http://www.youtube.com/watch?v=hx1mjT73xYE"><img src="https://i.ytimg.com/vi/hx1mjT73xYE/default.jpg"></a></div>')
 
+    @override_settings(INLINE_IMAGE_PREVIEW=True)
+    def test_inline_image_preview(self):
+        # type: () -> None
+        with_preview = '<p><a href="http://cdn.wallpapersafari.com/13/6/16eVjx.jpeg" target="_blank" title="http://cdn.wallpapersafari.com/13/6/16eVjx.jpeg">http://cdn.wallpapersafari.com/13/6/16eVjx.jpeg</a></p>\n<div class="message_inline_image"><a href="http://cdn.wallpapersafari.com/13/6/16eVjx.jpeg" target="_blank" title="http://cdn.wallpapersafari.com/13/6/16eVjx.jpeg"><img src="https://external-content.zulipcdn.net/389b5d7148a0cbc7475ed564e1b03ceb476bdacb/687474703a2f2f63646e2e77616c6c70617065727361666172692e636f6d2f31332f362f313665566a782e6a706567"></a></div>'
+        without_preview = '<p><a href="http://cdn.wallpapersafari.com/13/6/16eVjx.jpeg" target="_blank" title="http://cdn.wallpapersafari.com/13/6/16eVjx.jpeg">http://cdn.wallpapersafari.com/13/6/16eVjx.jpeg</a></p>'
+        content = 'http://cdn.wallpapersafari.com/13/6/16eVjx.jpeg'
+
+        sender_user_profile = get_user_profile_by_email("othello@zulip.com")
+        msg = Message(sender=sender_user_profile, sending_client=get_client("test"))
+        converted = render_markdown(msg, content)
+        self.assertEqual(converted, with_preview)
+
+        realm = msg.get_realm()
+        setattr(realm, 'inline_image_preview', False)
+        realm.save()
+
+        sender_user_profile = get_user_profile_by_email("othello@zulip.com")
+        msg = Message(sender=sender_user_profile, sending_client=get_client("test"))
+        converted = render_markdown(msg, content)
+        self.assertEqual(converted, without_preview)
+
+    @override_settings(INLINE_IMAGE_PREVIEW=False)
+    def test_image_preview_enabled_for_realm(self):
+        # type: () -> None
+        ret = bugdown.image_preview_enabled_for_realm()
+        self.assertEqual(ret, False)
+
+        settings.INLINE_IMAGE_PREVIEW = True
+
+        sender_user_profile = get_user_profile_by_email("othello@zulip.com")
+        bugdown.current_message = copy.deepcopy(Message(sender=sender_user_profile, sending_client=get_client("test")))
+        realm = bugdown.current_message.get_realm()
+
+        ret = bugdown.image_preview_enabled_for_realm()
+        self.assertEqual(ret, realm.inline_image_preview)
+
+        bugdown.current_message = None
+        ret = bugdown.image_preview_enabled_for_realm()
+        self.assertEqual(ret, True)
+
+    @override_settings(INLINE_URL_EMBED_PREVIEW=False)
+    def test_url_embed_preview_enabled_for_realm(self):
+        # type: () -> None
+        sender_user_profile = get_user_profile_by_email("othello@zulip.com")
+        message = copy.deepcopy(Message(sender=sender_user_profile, sending_client=get_client("test")))
+        realm = message.get_realm()
+
+        ret = bugdown.url_embed_preview_enabled_for_realm(message)
+        self.assertEqual(ret, False)
+
+        settings.INLINE_URL_EMBED_PREVIEW = True
+
+        ret = bugdown.url_embed_preview_enabled_for_realm(message)
+        self.assertEqual(ret, realm.inline_image_preview)
+
+        message = None
+        ret = bugdown.url_embed_preview_enabled_for_realm(message)
+        self.assertEqual(ret, True)
+
     def test_inline_dropbox(self):
         # type: () -> None
         msg = 'Look at how hilarious our old office was: https://www.dropbox.com/s/ymdijjcg67hv2ta/IMG_0923.JPG'

zerver/tests/test_events.py

@@ -51,6 +51,8 @@ from zerver.lib.actions import (
     do_set_realm_invite_by_admins_only,
     do_set_name_changes_disabled,
     do_set_email_changes_disabled,
+    do_set_realm_inline_image_preview,
+    do_set_realm_inline_url_embed_preview,
     do_set_realm_message_editing,
     do_set_realm_default_language,
     do_set_realm_authentication_methods,
@@ -711,6 +713,34 @@ class EventsRegisterTest(ZulipTestCase):
             error = schema_checker('events[0]', events[0])
             self.assert_on_error(error)
 
+    def test_change_realm_inline_image_preview(self):
+        # type: () -> None
+        schema_checker = check_dict([
+            ('type', equals('realm')),
+            ('op', equals('update')),
+            ('property', equals('inline_image_preview')),
+            ('value', check_bool),
+        ])
+        do_set_realm_inline_image_preview(self.user_profile.realm, inline_image_preview=False)
+        for inline_image_preview in (True, False):
+            events = self.do_test(lambda: do_set_realm_inline_image_preview(self.user_profile.realm, inline_image_preview))
+            error = schema_checker('events[0]', events[0])
+            self.assert_on_error(error)
+
+    def test_change_realm_inline_url_embed_preview(self):
+        # type: () -> None
+        schema_checker = check_dict([
+            ('type', equals('realm')),
+            ('op', equals('update')),
+            ('property', equals('inline_url_embed_preview')),
+            ('value', check_bool),
+        ])
+        do_set_realm_inline_url_embed_preview(self.user_profile.realm, inline_url_embed_preview=False)
+        for inline_url_embed_preview in (True, False):
+            events = self.do_test(lambda: do_set_realm_inline_url_embed_preview(self.user_profile.realm, inline_url_embed_preview))
+            error = schema_checker('events[0]', events[0])
+            self.assert_on_error(error)
+
     def test_change_realm_default_language(self):
         # type: () -> None
         schema_checker = check_dict([

zerver/tests/test_home.py

@@ -105,6 +105,8 @@ class HomeTest(ZulipTestCase):
             "realm_filters",
             "realm_icon_source",
             "realm_icon_url",
+            "realm_inline_image_preview",
+            "realm_inline_url_embed_preview",
             "realm_invite_by_admins_only",
             "realm_invite_required",
             "realm_message_content_edit_limit_seconds",
@@ -117,6 +119,8 @@ class HomeTest(ZulipTestCase):
             "referrals",
             "save_stacktraces",
             "server_generation",
+            "server_inline_image_preview",
+            "server_inline_url_embed_preview",
             "server_uri",
             "share_the_love",
             "show_digest_email",

zerver/tests/test_link_embed.py

@@ -256,6 +256,20 @@ class PreviewTestCase(ZulipTestCase):
         msg = self._send_message_with_test_org_url(sender_email='prospero@zulip.com')
         self.assertIn(embedded_link, msg.rendered_content)
 
+    def test_inline_url_embed_preview(self):
+        # type: () -> None
+        with_preview = '<p><a href="http://test.org/" target="_blank" title="http://test.org/">http://test.org/</a></p>\n<div class="message_embed"><a class="message_embed_image" href="http://test.org/" style="background-image: url(http://ia.media-imdb.com/images/rock.jpg)" target="_blank"></a><div class="data-container"><div class="message_embed_title"><a href="http://test.org/" target="_blank" title="The Rock">The Rock</a></div><div class="message_embed_description">Description text</div></div></div>'
+        without_preview = '<p><a href="http://test.org/" target="_blank" title="http://test.org/">http://test.org/</a></p>'
+        msg = self._send_message_with_test_org_url(sender_email='hamlet@zulip.com')
+        self.assertEqual(msg.rendered_content, with_preview)
+
+        realm = msg.get_realm()
+        setattr(realm, 'inline_url_embed_preview', False)
+        realm.save()
+
+        msg = self._send_message_with_test_org_url(sender_email='prospero@zulip.com', queue_should_run=False)
+        self.assertEqual(msg.rendered_content, without_preview)
+
     def test_http_error_get_data(self):
         # type: () -> None
         url = 'http://test.org/'

zerver/tests/test_realm.py

@@ -135,6 +135,20 @@ class RealmTest(ZulipTestCase):
         realm = update_with_api(invite_by_admins_only=False)
         self.assertEqual(realm.invite_by_admins_only, False)
 
+        # inline_image_preview
+        set_up_db('inline_image_preview', True)
+        realm = update_with_api(inline_image_preview=False)
+        self.assertEqual(realm.inline_image_preview, False)
+        realm = update_with_api(inline_image_preview=True)
+        self.assertEqual(realm.inline_image_preview, True)
+
+        # inline_url_embed_preview
+        set_up_db('inline_url_embed_preview', False)
+        realm = update_with_api(inline_url_embed_preview=True)
+        self.assertEqual(realm.inline_url_embed_preview, True)
+        realm = update_with_api(inline_url_embed_preview=False)
+        self.assertEqual(realm.inline_url_embed_preview, False)
+
         # create_stream_by_admins_only
         set_up_db('create_stream_by_admins_only', False)
         realm = update_with_api(create_stream_by_admins_only=True)

zerver/views/home.py

@@ -206,6 +206,8 @@ def home_real(request):
         server_generation     = settings.SERVER_GENERATION,
         use_websockets        = settings.USE_WEBSOCKETS,
         save_stacktraces      = settings.SAVE_FRONTEND_STACKTRACES,
+        server_inline_image_preview = settings.INLINE_IMAGE_PREVIEW,
+        server_inline_url_embed_preview = settings.INLINE_URL_EMBED_PREVIEW,
 
         # realm data.
         # TODO: Move all of these data to register_ret and pull from there
@@ -299,6 +301,8 @@ def home_real(request):
         'realm_icon_source',
         'realm_icon_url',
         'realm_invite_by_admins_only',
+        'realm_inline_image_preview',
+        'realm_inline_url_embed_preview',
         'realm_invite_required',
         'realm_message_content_edit_limit_seconds',
         'realm_name',

zerver/views/messages.py

@@ -972,6 +972,7 @@ def update_message_backend(request, user_profile,
     message, ignored_user_message = access_message(user_profile, message_id)
 
     # You only have permission to edit a message if:
+    # you change this value also change those two parameters in message_edit.js.
     # 1. You sent it, OR:
     # 2. This is a topic-only edit for a (no topic) message, OR:
     # 3. This is a topic-only edit and you are an admin.
@@ -1034,7 +1035,7 @@ def update_message_backend(request, user_profile,
                                        propagate_mode, content, rendered_content)
     # Include the number of messages changed in the logs
     request._log_data['extra'] = "[%s]" % (number_changed,)
-    if links_for_embed and getattr(settings, 'INLINE_URL_EMBED_PREVIEW', None):
+    if links_for_embed and bugdown.url_embed_preview_enabled_for_realm(message):
         event_data = {
             'message_id': message.id,
             'message_content': message.content,

zerver/views/realm.py

@@ -12,6 +12,8 @@ from zerver.lib.actions import (
     do_set_realm_invite_by_admins_only,
     do_set_name_changes_disabled,
     do_set_email_changes_disabled,
+    do_set_realm_inline_image_preview,
+    do_set_realm_inline_url_embed_preview,
     do_set_realm_add_emoji_by_admins_only,
     do_set_realm_invite_required,
     do_set_realm_message_editing,
@@ -35,6 +37,8 @@ def update_realm(request, user_profile, name=REQ(validator=check_string, default
                  invite_by_admins_only=REQ(validator=check_bool, default=None),
                  name_changes_disabled=REQ(validator=check_bool, default=None),
                  email_changes_disabled=REQ(validator=check_bool, default=None),
+                 inline_image_preview=REQ(validator=check_bool, default=None),
+                 inline_url_embed_preview=REQ(validator=check_bool, default=None),
                  create_stream_by_admins_only=REQ(validator=check_bool, default=None),
                  add_emoji_by_admins_only=REQ(validator=check_bool, default=None),
                  allow_message_editing=REQ(validator=check_bool, default=None),
@@ -42,7 +46,7 @@ def update_realm(request, user_profile, name=REQ(validator=check_string, default
                  default_language=REQ(validator=check_string, default=None),
                  waiting_period_threshold=REQ(converter=to_non_negative_int, default=None),
                  authentication_methods=REQ(validator=check_dict([]), default=None)):
-    # type: (HttpRequest, UserProfile, Optional[str], Optional[str], Optional[bool], Optional[bool], Optional[bool], Optional[bool], Optional[bool], Optional[bool], Optional[bool], Optional[bool], Optional[int], Optional[str], Optional[int], Optional[dict]) -> HttpResponse
+    # type: (HttpRequest, UserProfile, Optional[str], Optional[str], Optional[bool], Optional[bool], Optional[bool], Optional[bool], Optional[bool], Optional[bool], Optional[bool], Optional[bool], Optional[bool], Optional[bool], Optional[int], Optional[str], Optional[int], Optional[dict]) -> HttpResponse
     # Validation for default_language
     if default_language is not None and default_language not in get_available_language_codes():
         raise JsonableError(_("Invalid language '%s'" % (default_language,)))
@@ -71,6 +75,12 @@ def update_realm(request, user_profile, name=REQ(validator=check_string, default
     if email_changes_disabled is not None and realm.email_changes_disabled != email_changes_disabled:
         do_set_email_changes_disabled(realm, email_changes_disabled)
         data['email_changes_disabled'] = email_changes_disabled
+    if inline_image_preview is not None and realm.inline_image_preview != inline_image_preview:
+        do_set_realm_inline_image_preview(realm, inline_image_preview)
+        data['inline_image_preview'] = inline_image_preview
+    if inline_url_embed_preview is not None and realm.inline_url_embed_preview != inline_url_embed_preview:
+        do_set_realm_inline_url_embed_preview(realm, inline_url_embed_preview)
+        data['inline_url_embed_preview'] = inline_url_embed_preview
     if authentication_methods is not None and realm.authentication_methods_dict() != authentication_methods:
         if True not in list(authentication_methods.values()):
             return json_error(_("At least one authentication method must be enabled."),