streams: Add frontend to set/update message_retention_days of a stream.

This commit adds frontend support for setting and updating message
retention days of a stream from stream settings.

Message retention days can be changed from stream privacy modal of the
stream and can be set from stream_creation_form while creating streams.

Only admins can create streams with message_retention_days value other
than realm_default.

This commit also contains relevant changes to docs.

frontend_tests/node_tests/stream_data.js

@@ -474,6 +474,7 @@ run_test('stream_settings', () => {
         invite_only: true,
         history_public_to_subscribers: true,
         stream_post_policy: stream_data.stream_post_policy_values.admins.code,
+        message_retention_days: 10,
     };
     stream_data.clear_subscriptions();
     stream_data.add_sub(cinnamon);
@@ -496,6 +497,7 @@ run_test('stream_settings', () => {
     assert.equal(sub_rows[0].history_public_to_subscribers, true);
     assert.equal(sub_rows[0].stream_post_policy ===
         stream_data.stream_post_policy_values.admins.code, true);
+    assert.equal(sub_rows[0].message_retention_days, 10);
 
     const sub = stream_data.get_sub('a');
     stream_data.update_stream_privacy(sub, {
@@ -503,11 +505,13 @@ run_test('stream_settings', () => {
         history_public_to_subscribers: false,
     });
     stream_data.update_stream_post_policy(sub, 1);
+    stream_data.update_message_retention_setting(sub, -1);
     stream_data.update_calculated_fields(sub);
     assert.equal(sub.invite_only, false);
     assert.equal(sub.history_public_to_subscribers, false);
     assert.equal(sub.stream_post_policy,
                  stream_data.stream_post_policy_values.everyone.code);
+    assert.equal(sub.message_retention_days, -1);
 
     // For guest user only retrieve subscribed streams
     sub_rows = stream_data.get_updated_unsorted_subs();

frontend_tests/node_tests/stream_events.js

@@ -156,6 +156,17 @@ run_test('update_property', () => {
             assert.equal(args.val, stream_data.stream_post_policy_values.admins.code);
         });
     });
+
+    // Test stream message_retention_days change event
+    with_overrides(function (override) {
+        global.with_stub(function (stub) {
+            override('stream_data.update_message_retention_setting', stub.f);
+            stream_events.update_property(1, 'message_retention_days', 20);
+            const args = stub.get_args('sub', 'val');
+            assert.equal(args.sub.stream_id, 1);
+            assert.equal(args.val, 20);
+        });
+    });
 });
 
 run_test('marked_subscribed', () => {

static/js/stream_create.js

@@ -169,6 +169,13 @@ function create_stream() {
 
     data.stream_post_policy = JSON.stringify(stream_post_policy);
 
+    let message_retention_selection = $('#stream_creation_form select[name=stream_message_retention_setting]').val();
+    if (message_retention_selection === "retain_for_period") {
+        message_retention_selection = parseInt($('#stream_creation_form input[name=stream-message-retention-days]').val(), 10);
+    }
+
+    data.message_retention_days = JSON.stringify(message_retention_selection);
+
     const announce = stream_data.realm_has_notifications_stream() &&
         $('#announce-new-stream input').prop('checked');
     data.announce = JSON.stringify(announce);
@@ -266,6 +273,8 @@ exports.show_new_stream_modal = function () {
     // Make the options default to the same each time:
     // public, "announce stream" on.
     $('#make-invite-only input:radio[value=public]').prop('checked', true);
+    $("#stream_creation_form .stream-message-retention-days-input").hide();
+    $("#stream_creation_form select[name=stream_message_retention_setting]").val("realm_default");
 
     if (stream_data.realm_has_notifications_stream()) {
         $('#announce-new-stream').show();

static/js/stream_data.js

@@ -427,6 +427,10 @@ exports.update_stream_privacy = function (sub, values) {
     sub.history_public_to_subscribers = values.history_public_to_subscribers;
 };
 
+exports.update_message_retention_setting  = function (sub, message_retention_days) {
+    sub.message_retention_days = message_retention_days;
+};
+
 exports.receives_notifications = function (stream_name, notification_name) {
     const sub = exports.get_sub(stream_name);
     if (sub === undefined) {

static/js/stream_edit.js

@@ -63,6 +63,34 @@ exports.get_users_from_subscribers = function (subscribers) {
     });
 };
 
+exports.get_display_text_for_realm_message_retention_setting = function () {
+    const realm_message_retention_days = page_params.realm_message_retention_days;
+    if (realm_message_retention_days === -1 || realm_message_retention_days === null) {
+        return i18n.t("(forever)");
+    }
+    return i18n.t("(__message_retention_days__ days)", {message_retention_days: realm_message_retention_days});
+};
+
+function change_stream_message_retention_days_block_display_property(value) {
+    if (value === "retain_for_period") {
+        $('.stream-message-retention-days-input').show();
+    } else {
+        $('.stream-message-retention-days-input').hide();
+    }
+}
+
+function set_stream_message_retention_setting_dropdown(stream) {
+    let value = "retain_for_period";
+    if (stream.message_retention_days === null) {
+        value = "realm_default";
+    } else if (stream.message_retention_days === -1) {
+        value = "forever";
+    }
+
+    $(".stream_message_retention_setting").val(value);
+    change_stream_message_retention_days_block_display_property(value);
+}
+
 function clear_edit_panel() {
     $(".display-type #add_new_stream_title").hide();
     $(".display-type #stream_settings_title, .right .settings").show();
@@ -380,6 +408,7 @@ function change_stream_privacy(e) {
 
     const privacy_setting = $('#stream_privacy_modal input[name=privacy]:checked').val();
     const stream_post_policy = parseInt($('#stream_privacy_modal input[name=stream-post-policy]:checked').val(), 10);
+    let message_retention_days = $('#stream_privacy_modal select[name=stream_message_retention_setting]').val();
 
     let invite_only;
     let history_public_to_subscribers;
@@ -395,6 +424,10 @@ function change_stream_privacy(e) {
         history_public_to_subscribers = true;
     }
 
+    if (message_retention_days === 'retain_for_period') {
+        message_retention_days = parseInt($('#stream_privacy_modal input[name=stream-message-retention-days]').val(), 10);
+    }
+
     $(".stream_change_property_info").hide();
     const data = {
         stream_name: sub.name,
@@ -402,6 +435,7 @@ function change_stream_privacy(e) {
         is_private: JSON.stringify(invite_only),
         stream_post_policy: JSON.stringify(stream_post_policy),
         history_public_to_subscribers: JSON.stringify(history_public_to_subscribers),
+        message_retention_days: JSON.stringify(message_retention_days),
     };
 
     channel.patch({
@@ -523,10 +557,17 @@ exports.initialize = function () {
             is_private_with_public_history: stream.invite_only &&
                 stream.history_public_to_subscribers,
             is_admin: page_params.is_admin,
+            zulip_plan_is_not_limited: page_params.zulip_plan_is_not_limited,
+            stream_message_retention_days: stream.message_retention_days,
+            realm_message_retention_setting:
+                exports.get_display_text_for_realm_message_retention_setting(),
+            upgrade_text_for_wide_organization_logo:
+                page_params.upgrade_text_for_wide_organization_logo,
         };
         const change_privacy_modal = render_subscription_stream_privacy_modal(template_data);
         $("#stream_privacy_modal").remove();
         $("#subscriptions_table").append(change_privacy_modal);
+        set_stream_message_retention_setting_dropdown(stream);
         overlays.open_modal('#stream_privacy_modal');
         e.preventDefault();
         e.stopPropagation();
@@ -687,6 +728,11 @@ exports.initialize = function () {
             exports.open_edit_panel_for_row(this);
         }
     });
+
+    $("#subscriptions_table").on("change", ".stream_message_retention_setting", function (e) {
+        const dropdown_value = e.target.value;
+        change_stream_message_retention_days_block_display_property(dropdown_value);
+    });
 };
 
 window.stream_edit = exports;

static/js/stream_events.js

@@ -55,6 +55,9 @@ exports.update_property = function (stream_id, property, value, other_values) {
     case 'stream_post_policy':
         subs.update_stream_post_policy(sub, value);
         break;
+    case 'message_retention_days':
+        stream_data.update_message_retention_setting(sub, value);
+        break;
     default:
         blueslip.warn("Unexpected subscription property type", {property: property,
                                                                 value: value});

static/js/subs.js

@@ -586,6 +586,11 @@ exports.setup_page = function (callback) {
             is_admin: page_params.is_admin,
             stream_post_policy_values: stream_data.stream_post_policy_values,
             stream_post_policy: stream_data.stream_post_policy_values.everyone.code,
+            zulip_plan_is_not_limited: page_params.zulip_plan_is_not_limited,
+            realm_message_retention_setting:
+                stream_edit.get_display_text_for_realm_message_retention_setting,
+            upgrade_text_for_wide_organization_logo:
+                page_params.upgrade_text_for_wide_organization_logo,
         };
 
         const rendered = render_subscription_table_body(template_data);

static/styles/subscriptions.scss

@@ -1061,6 +1061,20 @@ ul.grey-box {
                 margin-right: 5px;
             }
         }
+
+        input[type=text] {
+            width: 5ch;
+            text-align: right;
+        }
+
+        label.dropdown-title {
+            display: block;
+        }
+
+        select {
+            width: auto;
+            margin-bottom: 0px;
+        }
     }
 }
 

static/templates/stream_types.hbs

@@ -31,4 +31,33 @@
         </label>
     </li>
     {{/each}}
+    {{#if is_admin}}
+    <h4>{{t "Message retention for stream" }}</h4>
+
+    {{> settings/upgrade_tip_widget}}
+
+    <li>
+        <div class="input-group inline-block">
+            <label for="stream_message_retention_setting" class="dropdown-title">{{t "Message retention period" }}</label>
+            <select name="stream_message_retention_setting"
+              class="stream_message_retention_setting" class="prop-element"
+              {{#unless zulip_plan_is_not_limited}}disabled{{/unless}}>
+                <option value="realm_default">{{t 'Use organization level settings '}}{{realm_message_retention_setting}} </option>
+                <option value="forever">{{t 'Retain forever' }}</option>
+                <option value="retain_for_period">{{t 'Retain for N days after posting' }}</option>
+            </select>
+
+            <div class="dependent-inline-block stream-message-retention-days-input">
+                <label class="inline-block">
+                    {{t 'N' }}:
+                </label>
+                <input type="text" autocomplete="off"
+                  name="stream-message-retention-days"
+                  class="stream-message-retention-days"
+                  value="{{ stream_message_retention_days }}"
+                  {{#unless zulip_plan_is_not_limited}}disabled{{/unless}}/>
+            </div>
+        </div>
+    </li>
+    {{/if}}
 </ul>