.. _microxrceddsgen_label:

eProsima Micro XRCE-DDS Gen
===========================

*eProsima Micro XRCE-DDS Gen* is a Java application used to generate source code for the *eProsima Micro XRCE-DDS* software.

This tool can generate from a given IDL specification file, the C struct associated with the
Topic, as well as the serialization and deserialization methods.
Also, it can generate a sample demo that works with the proposed topic.

To find out how to install this package, refer to the :ref:`install_gen` section.

As an example of the potential of this tool, the following shows the source code generated from the ShapeDemo IDL file.

::

    // ShapeType.idl

    struct ShapeType {
        @key string color;
        long x;
        long y;
        long shapesize;
    };

If we will perform the following command: ::

   $ microxrceddsgen ShapeType.idl

it will generate the following header file and its corresponding source:

.. code-block:: C

    /*!
     * @file ShapeType.h
     * This header file contains the declaration of the described types in the IDL file.
     *
     * This file was generated by the tool gen.
     */

    #ifndef _ShapeType_H_
    #define _ShapeType_H_

    #include <stdint.h>
    #include <stdbool.h>

    /*!
     * @brief This struct represents the structure ShapeType defined by the user in the IDL file.
     * @ingroup SHAPETYPE
     */
    typedef struct ShapeType
    {
        char color[255];
        int32_t x;
        int32_t y;
        int32_t shapesize;

    } ShapeType;

    struct ucdrBuffer;

    bool ShapeType_serialize_topic(struct ucdrBuffer* writer, const ShapeType* topic);
    bool ShapeType_deserialize_topic(struct ucdrBuffer* reader, ShapeType* topic);
    uint32_t ShapeType_size_of_topic(const ShapeType* topic, uint32_t size);

    #endif // _ShapeType_H_


*eProsima Micro XRCE-DDS Gen* is also able to generate both *publisher* and *subscriber* source code examples, related with the topic specified in the IDL file, by adding the flag ``-example``: ::

    $ microxrceddsgen -example <file.idl>


The *Client* library must be compiled with the ``WRITE_ACCESS_PROFILE`` option for the *publisher*, to use these examples
and the ``READ_ACCESS_PROFILE`` option for the *subscriber*.

.. note::

    At present, *eProsima Micro XRCE-DDS Gen* only supports Structs composed of integer, string, array and sequence types,
    even though it is planned to enhance the capabilities of the *eProsima Micro XRCE-DDS Gen* tool in a near future.