Saturday, September 26, 2009

More on globals and classes in Caché

Interesting - it seems that "dynamic languages" have been around for much longer than (us) Ruby users would think. Here's Caché's own version of it at work:

Class Definition: TransactionData

/// Test class - Julian, Sept 2009
Class User.TransactionData Extends %Persistent
Property Message As %String;
Property Token As %Integer;

Routine: test.mac

Set ^tdp = ##class(User.TransactionData).%New()
Set ^tdp.Message = "XXXX^QPR^JTX"
Set ^tdp.Token = 131

Write !, "Created: " _ ^tdp


USER> do ^test
... Created 1@User.TransactionData

Studio: Globals

^tdp = "1@User.TransactionData"
^tdp.Message = "XXXX^QPR^JTX"
^tdp.Token = 131

The order of creation is:
  1. create the class
  2. this will create the SQL objects
  3. populating the SQL table will instantiate the globals
  4. the globals are: classD for data, classI for index

Objects can be created (%New)/opened(%OpenId) from code, but to be saved (%Save: which will update the database), the restrictions must be met (required properties, unique indexes, etc).

Also, I finally got the .NET gateway generator to work: it creates native .NET classes that can communicate with Cache objects. Here is a sample of the client code:

InterSystems.Data.CacheClient.CacheConnection cn = new InterSystems.Data.CacheClient.CacheConnection("Server=Irikiki; Port=1972;" +
"Log File = D:\\CacheNet\\DotNetCurrentAccess.log; Namespace = USER;" +
"Password = ______; USER ID = ____");
PatientInfo pi = new PatientInfo(cn);
pi.PatientName = "New Patient";
pi.PatientID = new byte[1]{6};
InterSystems.Data.CacheTypes.CacheStatus x = pi.Save();

PatientInfo is a class defined in Cache, as follows:

Class User.PatientInfo Extends %Persistent

Property PatientName As %String [ Required ];
Property PatientDOB As %Date;
Property PatientID As %ObjectIdentity;

Method getVersion() As %String
Quit "Version 1.0"

Index IndexPatientName On PatientName;
Index IndexPatientId On PatientID [ IdKey, PrimaryKey, Unique ];


Easy enough, the getVersion() method is available to the C# code, as are the persistence and all the other methdods natively available in ObjectScript. The generated code is here.