org-settings: Add setting to turn off welcome emails.

This adds an organization-level setting to provide an option to turn
off the welcome emails.

Fixes #8000.

static/js/admin.js

@@ -59,6 +59,7 @@ function _setup_page() {
         realm_icon_source: page_params.realm_icon_source,
         realm_icon_url: page_params.realm_icon_url,
         realm_mandatory_topics: page_params.realm_mandatory_topics,
+        realm_send_welcome_emails: page_params.realm_send_welcome_emails,
     };
 
     var admin_tab = templates.render('admin_tab', options);

static/js/server_events_dispatch.js

@@ -70,6 +70,7 @@ exports.dispatch_normal_event = function dispatch_normal_event(event) {
             name: notifications.redraw_title,
             name_changes_disabled: settings_org.toggle_name_change_display,
             notifications_stream_id: noop,
+            send_welcome_emails: noop,
             signup_notifications_stream_id: noop,
             restricted_to_domain: noop,
             waiting_period_threshold: noop,

static/js/settings_org.js

@@ -281,6 +281,11 @@ function _set_up() {
                 type: 'text',
                 msg: i18n.t("Default language changed!"),
             },
+            send_welcome_emails: {
+                type: 'bool',
+                checked_msg: i18n.t("Send emails to new users explaining how to use Zulip!"),
+                unchecked_msg: i18n.t("Don't send emails to new users explaining how to use Zulip!"),
+            },
             allow_message_deleting: {
                 type: 'bool',
                 checked_msg: i18n.t("Users can delete their messages!"),

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

@@ -3,6 +3,7 @@
         <div class="alert" id="admin-realm-notifications-stream-status"></div>
         <div class="alert" id="admin-realm-signup-notifications-stream-status"></div>
         <div class="alert" id="admin-realm-default-language-status"></div>
+        <div class="alert" id="admin-realm-send-welcome-emails-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>
@@ -133,6 +134,16 @@
                     {{/each}}
                 </select>
             </div>
+            <div class="input-group">
+                <label class="checkbox">
+                    <input type="checkbox" id="id_realm_send_welcome_emails" name="realm_send_welcome_emails"
+                           {{#if realm_send_welcome_emails}}checked="checked"{{/if}} />
+                    <span></span>
+                </label>
+                <label for="id_realm_send_welcome_emails" id="id_realm_send_welcome_emails_label" class="inline-block">
+                    {{t "Send emails introducing Zulip to new users" }}
+                </label>
+            </div>
             {{#if is_admin }}
             <div class="input-group organization-submission">
                 <button class="button rounded sea-green save-language-org-settings">

zerver/lib/actions.py

@@ -363,7 +363,8 @@ def process_new_human_user(user_profile: UserProfile,
         PreregistrationUser.objects.filter(email__iexact=user_profile.email).update(status=0)
 
     notify_new_user(user_profile)
-    enqueue_welcome_emails(user_profile)
+    if user_profile.realm.send_welcome_emails:
+        enqueue_welcome_emails(user_profile)
 
     # We have an import loop here; it's intentional, because we want
     # to keep all the onboarding code in zerver/lib/onboarding.py.

zerver/migrations/0140_realm_send_welcome_emails.py

@@ -0,0 +1,20 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.11.6 on 2018-02-18 07:02
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('zerver', '0139_fill_last_message_id_in_subscription_logs'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='realm',
+            name='send_welcome_emails',
+            field=models.BooleanField(default=True),
+        ),
+    ]

zerver/models.py

@@ -150,6 +150,7 @@ class Realm(models.Model):
     name_changes_disabled = models.BooleanField(default=False)  # type: bool
     email_changes_disabled = models.BooleanField(default=False)  # type: bool
     description = models.TextField(null=True)  # type: Optional[Text]
+    send_welcome_emails = models.BooleanField(default=True)  # type: bool
 
     allow_message_deleting = models.BooleanField(default=False)  # type: bool
     allow_message_editing = models.BooleanField(default=True)  # type: bool
@@ -196,6 +197,7 @@ class Realm(models.Model):
         name=Text,
         name_changes_disabled=bool,
         restricted_to_domain=bool,
+        send_welcome_emails=bool,
         waiting_period_threshold=int,
     )  # type: Dict[str, Union[type, Tuple[type, ...]]]
 

zerver/tests/test_home.py

@@ -141,6 +141,7 @@ class HomeTest(ZulipTestCase):
             "realm_password_auth_enabled",
             "realm_presence_disabled",
             "realm_restricted_to_domain",
+            "realm_send_welcome_emails",
             "realm_show_digest_email",
             "realm_signup_notifications_stream_id",
             "realm_uri",

zerver/views/realm.py

@@ -49,7 +49,8 @@ def update_realm(
         authentication_methods: Optional[Dict[Any, Any]]=REQ(validator=check_dict([]), default=None),
         notifications_stream_id: Optional[int]=REQ(validator=check_int, default=None),
         signup_notifications_stream_id: Optional[int]=REQ(validator=check_int, default=None),
-        message_retention_days: Optional[int]=REQ(converter=to_not_negative_int_or_none, default=None)
+        message_retention_days: Optional[int]=REQ(converter=to_not_negative_int_or_none, default=None),
+        send_welcome_emails: Optional[bool]=REQ(validator=check_bool, default=None)
 ) -> HttpResponse:
     realm = user_profile.realm