AllAccepted answers
Robert Cemper · Mar 7, 2018

Hi Evgeny,

class %DeepSee.UserPortal.DashboardViewer  has a property saveAction as %ZEN.Datatype.string;

Container for the current save mode for source control.

http://localhost:57774/csp/documatic/%25CSP.Documatic.cls?PAGE=CLASS&LIBRARY=samples&CLASSNAME=%25DeepSee.UserPortal.DashboardViewer#PROPERTY_saveAction

if you combine this with standard $system.OBJ.Export()  this may do it.

SAMPLES>s sc=$system.OBJ.Export("B*.DFI","DeepSee.xml")
 
Exporting to XML started on 03/07/2018 09:36:32
Exporting type : Basic Dashboard Demo.dashboard.DFI
Export finished successfully.
Robert Cemper · Mar 5, 2018

try to encode / decode your text to base64 to make sure you don't get in conflict with transmission control chars.

http://docs.intersystems.com/latest/csp/documatic/%25CSP.Documatic.cls?PAGE=CLASS&LIBRARY=%25SYS&CLASSNAME=%25SYSTEM.Encryption#METHOD_Base64Encode

http://docs.intersystems.com/latest/csp/documatic/%25CSP.Documatic.cls?PAGE=CLASS&LIBRARY=%25SYS&CLASSNAME=%25SYSTEM.Encryption#METHOD_Base64Decode

Robert Cemper · Mar 4, 2018

A good friend of mine provided this solution using also  JSON types and internal $LB() types for more detailed type analysis.
Of course there's no guaranty  for the hidden types in $LB() . 
 

types ; Show COS-Datatypes ; kav ; 2018-03-04
 //
 set obj=##class(Person).%New()
 write "VALUE",?15,"JSON",?22,"$LISTBUILD",! ,$TR($J("",32)," ","-"),!
 for val="453","abcd",1234,"abc"_$c(352), -34, 1.3, -7.9, $double(1.25),obj {
   write val,?15,$$TypeOf1(val),?22,$$TypeOf2(val,.txt),.txt! }
 quit
 // Return JSON datatype by the documented way
 //
TypeOf1(val) Public
{
  quit [(val)].%GetTypeOf(0) }
 // Return datatype by the undocumented $LB() way
 //
TypeOf2(val) Public
 { if $length(val)>253 { 
    set typ=$ziswide(val)+1 } 
  else { 
    set typ=$a($lb(val),2) }
  set txt=$case(typ
    ,1:" 8bitString"
    ,2:" 16bitString"
    ,4:" nonNegativeInteger"
    ,5:" negativeInteger"
    ,6:" nonNegativeFloat"
    ,7:" negativeFloat"
    ,8:" double"
    , :" ??? never seen before")
   quit typ
}
d ^types
VALUE          JSON   $LISTBUILD
--------------------------------
453            string 1 8bitString
abcd           string 1 8bitString
1234           number 4 nonNegativeInteger
abcŠ           string 2 16bitString
-34            number 5 negativeInteger
1.3            number 6 nonNegativeFloat
-7.9           number 7 negativeFloat
1.25           number 8 double
1@User.Person  oref   1 8bitString
 
Robert Cemper · Mar 1, 2018

the code causing the problem in MyClass.2.int looks most likely like this:

Set oid=$select(i%Myproperty="":"",1:$listbuild(i%Myproperty_""))

you are inside an ObjectMethod   and miss the actual Object  reference.
This happens when you try to access a property inside a Classmethod.
 classic mistake:

ClassMethod MyMethod(1,2,3) as %Status {
 set x=..Myproperty
}

correct use: 

ClassMethod MyMethod(oref,1,2,3) as %Status {
 set x=oref.Myproperty
}
Robert Cemper · Mar 1, 2018

Whether external backup or backup from a mirror (also asynchronous) or Caché backup you always have to identify
the point in time when your DB is logically consistent. What I think of is no open transactions, no open dependencies.

If you know that point in time you could separate your async mirror or shadow and run any backup from there.
Or just shut down your async server instance and run snapshots.
But there might also be a time gap between master and async server.
Once completed your async server can join again and catch up whatever time that may take.   
The critical point is to know when the async server has reached consistency.
But that depends on the application.
 

Robert Cemper · Feb 28, 2018

for a file stream it's a physical file, for a global stream it's a global or part of it.
if you clear it you either delete the file or the global (or its part )that holds the stream.
stream in Caché describes a sequence of persistent bytes on disk that you work on with dedicated common methods.

this must not be mixed up with a stream of characters on a network connection. if you miss a character there it's gone. 

Robert Cemper · Feb 28, 2018

Hi Alexey,
You hit the point: "lightweight"  just documents the relation.  Full stop. No further service.
You have to service (ie. Delete) it at both ends.
If you use a serial object with OREF + Status)  you still have to service both ends.

The "heavy" variant does it centralized at one place.
Though from storage point of view you move out the additional subscript level from array.

Robert Cemper · Feb 27, 2018

Hi, Evegeny!
for both variants you work along the array by GetNext() method
for each employee you have an array with the OREFs of the company. So you have the full object at hands.
similar the opposite direction from company to employee and employee->nae in SQL or employee.name

And as we always have a Collection type Array indexing is simple either by (KEY) or (ELEMENT). whether you  need the ID or the OREF
http://docs.intersystems.com/latest/csp/docbook/DocBook.UI.Page.cls?KEY=GSQLOPT_indices#GSQLOPT_indices_collections

The only tricky action is DELETE: there you have to have a method to "DisRelate" before delete.
But real commercial systems never delete anything. Just set a flag "isDeleted". Which is much easier for any "undo" action.