How do I find Metadata for a publication through its GUID using the API?

Question

I have the GUID, but I am not able to get Metadata for it. I am able to get it for Maps.

I used (Maybe I am using the wrong function. If so, what is the right one?):

var ext = new Trisoft.InfoShare.API25.DocumentObj();

string requestedMetadata = "<ishfields>" +
"<ishfield name='VERSION' level='version'/>" +
"<ishfield name='FTITLE' level='logical'/>" +
"<ishfield name='FSTATUS' level='lng'/>" +
"</ishfields>";

var version = mapVersion; // it is 2 in this case

var guid = "GUID-xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx";

var objectList = ext.GetMetadata(guid, ref version, "en", "", requestedMetadata);

Error I get:

Trisoft.InfoShare.Business.ObjectNotFoundException: The object GUID-11111111-2222-3333-4444-555555555555=2=en= does not exist. [co:"GUID-11111111-2222-3333-4444-555555555555=2=en="]
at Trisoft.InfoShare.Business.DocumentObject.GetComponentObject(String logicalId, CardTypes cardTypes, IshVersion& ishVersion, IshLovValue language, IshLovValue resolution, Boolean writable, Boolean throwIfNotFound, ComponentInformationSet& informationSet)
at Trisoft.InfoShare.Business.DocumentObject.GetMetadata(String logicalId, IshVersion& ishVersion, IshLovValue language, IshLovValue resolution, IshRequestedFields ishFieldsRequestedMetadata)
at Trisoft.InfoShare.API25.DocumentObj.GetMetadata(String logicalId, String& version, String language, String resolution, String xmlRequestedMetadata)

Dave De Meyer · Answer

Hi, 
 In short, the class DocumentObj25 covers content objects like OASIS Dita Maps, Topics, Library Topics, Images and Other. Because of business logic differences, publicaitons and publication outputs are handled over PublicationOutput25 class... Much of your code is good but the initial new is different. 
 I see you make assembly bound linking, do note that this requires a full Tridion Docs applicaiton server is involved. If possible I would suggest more soft linking by using the Public SOAP API calls. 
 A variation of your questions and some more background is on RE: Need to use the API or IshRemote to create publication objects 
 Best wishes, Dave

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How do I find Metadata for a publication through its GUID using the API?