Introduction to Plugin Development

Plugins allow you to extend the functionality of User Defined Data encoder and decoder without touching MisbCore SDK or encoding / decoding applications that use them.

Plugin location

MisbCore tries to locate plugins in a ./plugins subdirectory, so installing a plugin simply means copying the plugin binaries to this folder.

RVT User Defined Data plugin

The RVT User Defined Data plugin enables proprietary data encoding, decoding, and presentation within the MISB 601 and MISB 806 standards. Once your proprietary data is inserted into a STANAG 4609 stream, users with the plugin installed can seamlessly decode and display the user-defined data as JSON (or detailed JSON with field descriptions). Users without the plugin will see only a binary buffer.

Plugin interface

Every plugin for RvtUserDefinedData must implement IRvtUserDefinedData interface

public interface IRvtUserDefinedData
{
    /// <summary>
    /// Supported data type ids
    /// </summary>
    string[] DataTypes { get; }

    /// <summary>
    /// Brief plugin description
    /// </summary>
    string Description { get; }

    /// <summary>
    /// Decode Item buffer with user defined data
    /// </summary>
    /// <param name="id">string</param>  data type id
    /// <param name="tag">ushort</param> item tag
    /// <param name="buf">byte[]</param> item buffer
    /// <returns>JProperty</returns>
    JProperty DecodeItemBuffer(string id, ushort tag, byte[] buf);

    /// <summary>
    /// Encode packet with user defined data. 
    /// This method receives a json packet and returns a list of encoded values 
    /// </summary>
    /// <param name="pckt">JToken</param>
    /// <returns>List<Tuple<ushort, byte[]>></returns>
    List<Tuple<ushort, byte[]>> EncodeBuffer(JToken pckt);

    /// <summary>
    /// Convert json packet (compact to detailed)
    /// </summary>
    /// <param name="pckt">JObject</param>
    /// <returns>JObject</returns>
    JObject ToDetailed(JObject pckt);
}

Demo plugin

Plugin development is fairly straightforward - the code must implement the IRvtUserDefinedData interface. MISB 806 includes a demo project called RvtUserDefinedDataPluginDemo that illustrates this.

The demo shows some basic implementations for simple data types, such as bytes, integers, and strings. It also includes other values (such as latitude, longitude, and altitude) that require mapping based on a specified range, similar to the MISB0601 implementation.