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[22202] JSON to DynamicData deserializer #1093

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Mario-DL merged 2 commits into from
Jul 10, 2025
Merged

[22202] JSON to DynamicData deserializer #1093

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fbe5760
Refs #22202. JSON to DynamicData deserializer
juanlofer-eprosima Jul 4, 2025
62f7f96
Refs #22202. Apply suggestions
juanlofer-eprosima Jul 9, 2025
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62 changes: 52 additions & 10 deletions code/DDSCodeTester.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -1239,7 +1239,11 @@ class TypeIntrospectionSubscriber : public DomainParticipantListener

// Serialize DynamicType into its IDL representation
std::stringstream idl;
idl_serialize(remote_type, idl);
if (RETCODE_OK != idl_serialize(remote_type, idl))
{
// Error
return;
}

// Print IDL representation
std::cout << "Type discovered:\n" << idl.str() << std::endl;
Expand All @@ -1255,8 +1259,8 @@ class TypeIntrospectionSubscriber : public DomainParticipantListener
// Get remote type information
xtypes::TypeObject remote_type_object;
if (RETCODE_OK != DomainParticipantFactory::get_instance()->type_object_registry().get_type_object(
info.type_information.type_information.complete().typeid_with_size().type_id(),
remote_type_object))
info.type_information.type_information.complete().typeid_with_size().type_id(),
remote_type_object))
{
// Error
return;
Expand All @@ -1268,7 +1272,11 @@ class TypeIntrospectionSubscriber : public DomainParticipantListener

// Serialize DynamicType into its IDL representation
std::stringstream idl;
idl_serialize(remote_type, idl);
if (RETCODE_OK != idl_serialize(remote_type, idl))
{
// Error
return;
}

// Print IDL representation
std::cout << "Type discovered:\n" << idl.str() << std::endl;
Expand All @@ -1280,25 +1288,59 @@ class TypeIntrospectionSubscriber : public DomainParticipantListener
void on_data_available(
DataReader* reader)
{
// Dynamic DataType
// Create data using the DynamicType created from discovered TypeObject or through Dynamic Language Binding API
DynamicData::_ref_type new_data =
DynamicDataFactory::get_instance()->create_data(dyn_type_);
DynamicDataFactory::get_instance()->create_data(dyn_type_serialization_);

SampleInfo info;

while ((RETCODE_OK == reader->take_next_sample(&new_data, &info)))
{
std::stringstream output;
output << std::setw(4);

// Serialize DynamicData into JSON string format
json_serialize(new_data, DynamicDataJsonFormat::EPROSIMA, output);
if (RETCODE_OK != json_serialize(
new_data,
DynamicDataJsonFormat::EPROSIMA,
output))
{
// Error
return;
}

// Print JSON representation
std::cout << "Message received:\n" << output.str() << std::endl;
}
}

// DynamicType created in discovery callback
DynamicType::_ref_type dyn_type_;
// DynamicType corresponding to received data
DynamicType::_ref_type dyn_type_serialization_;
//!--

//!--

//!--JSON_DYNDATA_DESERIALIZATION
void json_to_data(
const std::string& json_data)
{
// Deserialize JSON string into DynamicData
// The required DynamicType can be created from discovered TypeObject or through Dynamic Language Binding API
DynamicData::_ref_type new_data;
if (RETCODE_OK != json_deserialize(
json_data,
dyn_type_deserialization_,
DynamicDataJsonFormat::EPROSIMA,
new_data))
{
// Error
return;
}

// Process the new data
}

// DynamicType corresponding to JSON data to be deserialized into DynamicData
DynamicType::_ref_type dyn_type_deserialization_;
//!--
};
//!--
Expand Down
1 change: 1 addition & 0 deletions docs/03-exports/aliases-api.include
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Expand Up @@ -1093,6 +1093,7 @@
.. |TypeObjectUtils-api| replace:: :cpp:class:`TypeObjectUtils <eprosima::fastdds::dds::xtypes::TypeObjectUtils>`
.. |XTypesUtils-idl_serialize-api| replace:: :cpp:func:`idl_serialize <eprosima::fastdds::dds::idl_serialize>`
.. |XTypesUtils-json_serialize-api| replace:: :cpp:func:`json_serialize <eprosima::fastdds::dds::json_serialize>`
.. |XTypesUtils-json_deserialize-api| replace:: :cpp:func:`json_deserialize <eprosima::fastdds::dds::json_deserialize>`
.. }}}

.. |DomainParticipant::set_listener-api| replace:: :cpp:func:`DomainParticipant::set_listener()<eprosima::fastdds::dds::DomainParticipant::set_listener>`
Expand Down
33 changes: 31 additions & 2 deletions docs/fastdds/xtypes/type_serializing.rst
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Expand Up @@ -53,8 +53,10 @@ remote type discovery.
:end-before: //!--
:dedent: 4

.. _xtypes_serialization_utilities_dyndata_json:

DynamicData to JSON
--------------------
-------------------

In the context of DDS (Data Distribution Service), |DynamicType-api| represents the structure of the data being
distributed across the system.
Expand All @@ -64,6 +66,8 @@ To enhance interoperability and readability, it is often useful to serialize |Dy
manageable format, to enable easier data processing and analysis across different systems and applications.
The method |XTypesUtils-json_serialize-api| converts a |DynamicData-api| object into a JSON object, then
dumped into a ``std::ostream``.
The inverse conversion is also possible using the method |XTypesUtils-json_deserialize-api|, as described in the
:ref:`corresponding section<xtypes_serialization_utilities_json_dyndata>`.

Supported Types
^^^^^^^^^^^^^^^
Expand Down Expand Up @@ -288,7 +292,7 @@ would be serialized as follows:
.. literalinclude:: /../code/json/Bitsets.json
:language: json

.. _xtypes_serialization_utilities_json_example:
.. _xtypes_serialization_utilities_dyndata_json_example:

Example: Convert received data into JSON format
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Expand All @@ -305,3 +309,28 @@ remote type discovery.
:dedent: 4
:start-after: //!--DYNDATA_JSON_SERIALIZATION
:end-before: //!--

.. _xtypes_serialization_utilities_json_dyndata:

JSON to DynamicData
-------------------

Apart from having the possibility to serialize :ref:`DynamicData to JSON<xtypes_serialization_utilities_dyndata_json>`,
Fast DDS also provides a way to perform the inverse conversion.
The method |XTypesUtils-json_deserialize-api| is able to convert a JSON object into a |DynamicData-api| instance,
by only providing its associated |DynamicType-api|.
This method is useful for injecting data from external sources into a DDS network, allowing for the integration of data
from various systems and applications.

.. _xtypes_serialization_utilities_json_dyndata_example:

Example: Convert JSON data into DynamicData
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
The following code demonstrates how to use the |XTypesUtils-json_deserialize-api| function in Fast DDS to convert
JSON data into a |DynamicData-api| object.

.. literalinclude:: /../code/DDSCodeTester.cpp
:language: c++
:dedent: 4
:start-after: //!--JSON_DYNDATA_DESERIALIZATION
:end-before: //!--