CLASSPARAMETERS are static and apply to class compile time. 
You refer to it by ..#paramname in your class code
https://cedocs.intersystems.com/latest/csp/docbook/Doc.View.cls?KEY=RCOS_fparameter
see section References to Other Class Members

or by  COS function $PARAMETER(class,parameter)

For Multiline SQL you may do it his way:

no solution for coloring inside a String 

on "html to pdf converter freeware" google gave me 3 270 000 hits.
Why reinventing the wheel. 
Place your HTML into a local file and let someone else do the dirty job.
There are enough solutions for a call-out to trigger the conversion.

#1) I'd suggest to increase the size of your LockTab as suggested by @Vic Sun 

#2) There is a class in %SYS .  ^SYS.Lock that could be useful for multiple  Lock deletes.
and as I just learned to adjust LockTab size (SetMaxLockTableSize) 
https://cedocs.intersystems.com/latest/csp/documatic/%25CSP.Documatic.cls?PAGE=CLASS&LIBRARY=%25SYS&CLASSNAME=SYS.Lock

#3) ^LOCKTAB from terminal command line in %SYS also shows the Locktab 

 

So a possible workaround could be to have a  VIEW on Oracle including ROWNUM as a column
like SELECT ROWNUM as row, * from  whatever_table
and then map the View instead of the original table just for this purpose.
 

see this example to reproduce and explain that there is an unnecessary conversion on the way

as you showed in your example
              "text": "Condição de pagamento sujeito a análise de crédito: "

you may take this example from OpenExchange:
 https://openexchange.intersystems.com/package/Light-weight-EXCEL-download

Al you have to do is to out-comment in  ClassMethod OnPreHTTP()  
this line :  #; set %response.ContentType="application/vnd.ms-excel"

and the table goes to your browser.

you have to mimic %Next() as %session.Data is a Multidimensional Array)

If I understand you correct you expect something  like

INSERT INTO new.MESSAGE (SELECT * from  EnsLib.HL7.Message  where id = ? )

this may work for rather modest designed relational tables but I doubt it will work for some complex structure as EnsLib.HL7.Message .

Subclassing is not the way to solve your problem for 2 reasons:

• A subclass has always to match the .IsA() class type of its parent    (e.g. Employee as subclass of Person. Employee is also always a Person)
• SubClasses share the storage with its parent. There are dirty tricks to avoid this but I assume you do not intend to change  EnsLib.HL7.Message.

There are ways to do something like this if you fiddle around in the storage structures. 
BUT: for reasons of transparency, documentation, and maintainability
I'd strongly recommend to use DTL. 

Fiddling around with COS in Ensemble is a rather tricky exercise.
Based on practical experience I can confirm that your successors will never forget you.

Hi Jenna,

I took some time to verify my suspicion.  (Caché 18.1)

You depend on the type of stream that is used in your object

#A)  %Library.GlobalBinaryStream or %Library.GlobalCharacterStream

• if you have no stream yet you run do obj.MyStream.Write("whatever") then your stream will land in ^SSA.DocumentCacheS as expected
• but if you get an already existing external stream and set obj.MyStream = myStreamOref then just the oref / OID of the stream is set including ^CacheStream.

Which seems to be your case   ​​​​​​​  
it's not a big surprise as ENSEMBLE may still use the old style. 

#B) using %Stream.GlobalBinary, ...

• Both cases ended as expected with the stream in ^SSA.DocumentCacheS It seems to me that a CopyFromStream happens during the assignment. I'd name it expected behavior.   

Hi Nigel,
About a year ago a faced a similar problem and found 2 possible workarounds.

Instead of writing a WS client a delegated it out to JavaScript.
#1)  Using CSP
#2) my preferred one with node.js
Both examples are available on OpenExchange 

Client for WebSockets based on CSP

Client for WebSockets based on Node.js

as Websockets ar so natural to JavaScript the result is no rocket science.

Stay healthy 

@Julius Kavay is fully correct.

The compiler was first written ~10 years before the idea of LLVM started  @ University of  Illinois.
Various interfaces allow your development very close to the data store. 

I'd suggest you contact your Sales Engineer @ InterSystems (Darmstadt ?) for disclosure of internals. 
 

why not use a free local mail server for testing?
I personally use the german speaking Hamster. But there are lots of them. Google is your friend

make your formula  f = x + 20(y*y) > z
a calculated, SQLcomputed property in your TABLE
and provide it with a bitmap index and it will run distributed and be incredible fast 

docs: 

https://docs.intersystems.com/iris20192/csp/docbook/DocBook.UI.Page.cls?KEY=GOBJ_proplit#GOBJ_proplit_computed
https://docs.intersystems.com/iris20192/csp/docbook/Doc.View.cls?KEY=RSQL_C145362
 

error -400 means there is an internal error

It might be caused by using object properties as  :context.anyname inside embedded SQL

give it a try and use "simple variables"  as :%myanyname , :%myShipmentTrackingNo 
and fill the context object outside the embedded SQL
as you do with SQLCODE

I'm surprised you don't see the obvious performance difference of looking for something of distinct length at the beginning of a string
vs. scanning an eventual rather long string for some bytes somewhere eventually including also composed strings as %AB%CD%.

keep in mind: Caché is built for speed, not for the comfort of the average programmer 

%STARTSWITH relates better to Caché internal structures and is faster in larger scale

USER>w $ZDATETIME($h,3)
2020-02-08 00:59:59
USER>w $ZDATETIME($h,-2)
1581120005

docs: https://cedocs.intersystems.com/latest/csp/docbook/DocBook.UI.Page.cls?KEY=RCOS_fzdatetime

Once the query is running it is not interested in any browser activity.

BUT:
the query is stopped when you fall into the session timeout
and the related process (and any query) is terminated.
SO it not running forever!

in Caché Terminal you may

;;; see I/O device guide for more details

The name of the io table is really just UTF8 with no hyphen !

So you force translation to internal format.