Hoe to add a persisten tag on a custom GH Component

Does anyone know how to add a persitant tag (string parameter) as an attribute or other property that can ibe instantiated once a custom gh component has been instantiead for the first time by the user?

I want this tag to be written somewhere as a persitent attribute to the component that can be re-read once the user saves a GH document and reopens it.

Basically this tag would tell teh user what instatiation number the component is on the canvas,

cheers

Replies to This Discussion

Permalink Reply by David Rutten on August 10, 2012 at 6:28am

Hi Steve,

can you please elaborate what you mean by "attribute", "property", "tag" and "persistent"?

David Rutten

david@mcneel.com

Poprad, Slovakia

Permalink Reply by Steve Lewis on August 15, 2012 at 11:00pm

I want my user to assign a nameID to my component. This is taken as a string input parameter. I want this name to be then be stored as a permanent variable by my custom component say - strOriginalComponentNameID.

When grasshopper is saved, the document closed, and the docuemnt reopened, I want the component to have stored this variable internally as a persistent data variable.

I know I can do this be changing the nickname variable of the component. This is updated, saved and restored when a document is closed and reopened. However, I dont want my component to allow user to chnage the Nickname. Right now though this is the only way i can think of doing this,

Steve

Permalink Reply by David Rutten on August 16, 2012 at 9:20am

Ok, I think I understand. You want to have private variables on your component that are (de)serialized, right?

To do this, you'll need to override the Write() and Read() methods:

Public Overrides Function Write(ByVal writer As GH_IWriter) As Boolean
writer.SetString("CustomNameID", m_customNameId)

Return MyBase.Write(writer)
End Function

Public Overrides Function Read(ByVal reader As GH_IReader) As Boolean
m_customNameId = Nothing
reader.TryGetString("CustomNameID", m_customNameId)

Return MyBase.Read(reader)
End Function

David Rutten

david@mcneel.com

Poprad, Slovakia

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