Caché-Error: <MAXSTRING>zgetAtFromArray+46^EnsLib.HL7.Segment.1
Hi,
we get HL7 MDM messages with embedded PDF documents that are Base64 encoded. When the embedded PDF document exceeds the size of 3.6 MB the following error occurs:
FEHLER <Ens>ErrBPTerminated: BP Main HL7 MDM # wird wegen folgenden Fehlers beendet: FEHLER #5002: Caché-Fehler: <MAXSTRING>zgetAtFromArray+46^EnsLib.HL7.Segment.1
> FEHLER #5002: Caché-Fehler: <MAXSTRING>zgetAtFromArray+46^EnsLib.HL7.Segment.1
In other posts I read that you can avoid these errors, if you use the data type %VarString instead of normal %String. Are there prebuilt classes that already use VarStrings or do I have to develop them on my own?
How do you work with large PDF documents in MDM messages? Do you keep them embedded or are you working with references to a file in a shared folder.
Thanks for your help.
Comments
if you take a look to method ##class(EnsLib.HL7.Segment).getAtFromArray(...)
you see that the segment data is assembled in row 1008 of the class by Set data=data_value
without checking the size.
So it is designed to fail with large documents as your Base64 encoded PDF (~+33% of original)
So just using a reference to an external stored file as you suggested should work.
BTW datatype %VarString is just a shortcut of %String(MAXLEN="") and a sometimes appropriate SQLTYPE.
There are methods for dealing with what are essentially embedded streams in HL7 Objects. See the methods GetFieldStreamRaw() and StoreFieldStreamRaw() in class EnsLib.HL7.Message; these are useful for copying streams from one message to another. If the need is to extract the Base64 stream as a binary stream for writing to a file, there's also GetFieldStreamBase64() in the same class; the stream obtained from it can be used with file-based streams to write to a disk file.
Thanks for your help. Now also large documents appear in the HIS.