Persistent Data

Dear forum.

I've been struggling with getting a persistent parameter to work on my component after a file save. Basically, I'm creating my own parameter using the GH_PersistentParam<T> class, where I'm using a GH_ObjectWrapper type. This may not be the best way about doing this, but it does work.

localSettings of type EM_Settings is the data that gets wrapped and then added to the Parameter.

Whilst everything works fine first time around, when I re-open the GH file the persistent data is lost. I need to serialize the data in some way in order to write it to a GH file and I'm not entirely sure how to do this.... I've tried for quite a while now, looking through the forum & SDK which offer clues but no joy... so I'm admitting defeat and running here!!!

Here are some of the CS bits:

public class MyComponent : GH_Component
{
    .........
    private EM_SettingsParam myParam;

    private EM_Settings localSettings;

    private EM_Settings mySettings;

    protected override void RegisterInputParams(GH_Component.GH_InputParamManager pm)
    {

          ...
       myParam = new EM_SettingsParam();
       EM_Settings localSettings = new EM_Settings();
       myParam.PersistentData.Append(new GH_ObjectWrapper(localSettings));
       pm.AddParameter(myParam, "Settings", "Se", "MySettings", GH_ParamAccess.item);
    }

    protected override void SolveInstance(IGH_DataAccess DA)
    {
       GH_ObjectWrapper temp = new GH_ObjectWrapper();
       if (!DA.GetData(5, ref temp)){ return; }
       mySettings = (EM_Settings)temp.Value;

       ...

    }
}


public class EM_SettingsParam : GH_PersistentParam<GH_ObjectWrapper>
{
     public EM_SettingsParam():
     base(new GH_InstanceDescription("Settings", "Settings", "Represents a collection of Settings", "Params", "Primitive"))
     {
     }

     ...blah singular blah plural blah exposure.hidden blah...

}

public class EM_Settings
{
     public bool Preview {get; set;}
     // (more parameters here)

     public EM_Settings()
     {
         Preview = true;
     }

}

Any help much appreciated $:)

John.