From 6cf519bfabdfd4281614c7dd5238fe0bbec92d38 Mon Sep 17 00:00:00 2001
From: Juan Lopez Fernandez <juanlopez@eprosima.com>
Date: Tue, 21 Jul 2026 09:44:21 +0200
Subject: [PATCH] Refs #24125. Add documentation for writer side filtering on
 late joiners

Signed-off-by: Juan Lopez Fernandez <juanlopez@eprosima.com>
---
 code/ProDDSCodeTester.cpp                     | 17 ++++++++-
 code/ProXMLTester.xml                         | 23 +++++++++++
 .../contentFilteredTopic/writerFiltering.rst  | 38 +++++++++++++++++++
 3 files changed, 77 insertions(+), 1 deletion(-)

diff --git a/code/ProDDSCodeTester.cpp b/code/ProDDSCodeTester.cpp
index 4ff4063fc..cb9671d7d 100644
--- a/code/ProDDSCodeTester.cpp
+++ b/code/ProDDSCodeTester.cpp
@@ -1,9 +1,10 @@
 #include <cstdint>
 
 #include <fastdds/dds/domain/qos/DomainParticipantQos.hpp>
+#include <fastdds/dds/publisher/qos/DataWriterQos.hpp>
 #include <fastdds/rtps/transport/ethernet/EthernetTransportDescriptor.hpp>
-#include <fastdds/rtps/transport/low-bandwidth/PayloadCompressionTransportDescriptor.hpp>
 #include <fastdds/rtps/transport/low-bandwidth/HeaderReductionTransportDescriptor.hpp>
+#include <fastdds/rtps/transport/low-bandwidth/PayloadCompressionTransportDescriptor.hpp>
 #include <fastdds/rtps/transport/udp_tsn/TSN_UDPv4TransportDescriptor.hpp>
 #include <fastdds/rtps/transport/udp_tsn/UDPPriorityMappings.hpp>
 
@@ -451,3 +452,17 @@ void rpcdds_custom_scheduling_examples()
     };
     //!--
 }
+
+void dds_domain_examples_pro()
+{
+    {
+        // CONTENT_FILTERING_ON_LATE_JOINERS_PROPERTY
+        DataWriterQos wqos;
+
+        // Enable content filtering on late joiners for this DataWriter
+        wqos.properties().properties().emplace_back(
+            "fastdds.content_filtering_on_late_joiners",
+            "true");
+        //!--
+    }
+}
diff --git a/code/ProXMLTester.xml b/code/ProXMLTester.xml
index ab41973f5..fea27a8a4 100644
--- a/code/ProXMLTester.xml
+++ b/code/ProXMLTester.xml
@@ -220,6 +220,29 @@
     </profiles>
 </dds>
 <-->
+<!--><-->
+
+<!-->CONTENT_FILTERING_ON_LATE_JOINERS_PROPERTY<-->
+<!--
+<?xml version="1.0" encoding="UTF-8" ?>
+<dds>
+    <profiles xmlns="http://www.eprosima.com">
+-->
+        <data_writer profile_name="cft_on_late_joiners_xml_profile">
+            <propertiesPolicy>
+                <properties>
+                    <!-- Enable content filtering on late joiners -->
+                    <property>
+                        <name>fastdds.content_filtering_on_late_joiners</name>
+                        <value>true</value>
+                    </property>
+                </properties>
+            </propertiesPolicy>
+        </data_writer>
+<!-->
+    </profiles>
+</dds>
+<-->
 <!--><-->
 
     </profiles>
diff --git a/docs/fastdds/dds_layer/topic/contentFilteredTopic/writerFiltering.rst b/docs/fastdds/dds_layer/topic/contentFilteredTopic/writerFiltering.rst
index 52f19270b..1f7fe56e8 100644
--- a/docs/fastdds/dds_layer/topic/contentFilteredTopic/writerFiltering.rst
+++ b/docs/fastdds/dds_layer/topic/contentFilteredTopic/writerFiltering.rst
@@ -49,3 +49,41 @@ Publications made after the updated discovery information is received will use t
 
 If some critical application considers this race condition issue unbearable, filtering on the writer side
 can be disabled by setting the maximum value on |WriterResourceLimitsQos::reader_filters_allocation-api| to 0.
+
+.. _dds_layer_topic_contentFilteredTopic_writer_side_late_joiners:
+
+Writer side filtering on late joiners |Pro|
+-------------------------------------------
+
+By default, when a late joiner DataReader is discovered (non-volatile durability scenario), the DataWriter will not
+apply the filter for that DataReader on historical samples.
+This means that the late joiner DataReader will receive all historical samples, even those that would not match its
+filter, which could cause performance degradation on resource-limited systems.
+
+It is possible however to configure a DataWriter to perform writer-side filtering on late joiners by setting the
+|DataWriterQos| property ``fastdds.content_filtering_on_late_joiners`` to ``true``.
+
+.. list-table::
+   :header-rows: 1
+   :align: left
+
+   * - PropertyPolicyQos name
+     - PropertyPolicyQos value
+     - Default value
+   * - ``"fastdds.content_filtering_on_late_joiners"``
+     - ``bool``
+     - ``false``
+
+.. tab-set-code::
+
+    .. literalinclude:: /../code/ProDDSCodeTester.cpp
+        :language: c++
+        :start-after: // CONTENT_FILTERING_ON_LATE_JOINERS_PROPERTY
+        :end-before: //!--
+        :dedent: 8
+
+    .. literalinclude:: /../code/ProXMLTester.xml
+        :language: xml
+        :start-after: <!-->CONTENT_FILTERING_ON_LATE_JOINERS_PROPERTY<-->
+        :end-before: <!--><-->
+        :lines: 2-4,6-16,18-19