If you wish to have a conditional filter, then you can use it this way

SELECT * FROM SomeTable
WHERE (:FilterName   = '' OR Name   LIKE :FilterName)
  AND (:FilterValue1 = '' OR Value1 LIKE :FilterValue1)
  AND (:FilterValue2 = '' OR Value2 LIKE :FilterValue2)

There is an interactive course about using IRIS REST and Angular, which you can try here, right from the browser, git it a try

What is the actual concern, then?

From my experience on different systems with highload, I did not see effects, that could point to think about it. 

Python may help

Class dc.Demo
{

ClassMethod ValidateJSON(data As %String = "") As %Status [ Language = python ]
{
import iris
import json
from json import JSONDecodeError

try:
    json.loads(data)
    return iris.system.Status.OK()
except JSONDecodeError as ex:
    return iris.system.Status.Error(5001, f"{ex.msg}: line {ex.lineno} column {ex.colno} (char {ex.pos})")
except Exception as ex:
    return iris.system.Status.Error(5001, repr(ex))
}

}

And result

USER>set status = ##class(dc.Demo).ValidateJSON("{""aa"":123 ""name"": ""value""}") do:'status $system.OBJ.DisplayError(status) 
ERROR #5001: Expecting ',' delimiter: line 1 column 11 (char 10)

USER>set status = ##class(dc.Demo).ValidateJSON("{""aa"": true, ") do:'status $system.OBJ.DisplayError(status) 
ERROR #5001: Expecting property name enclosed in double quotes: line 1 column 14 (char 13)

USER>set status = ##class(dc.Demo).ValidateJSON("{""aa"": wrong ") do:'status $system.OBJ.DisplayError(status) 
ERROR #5001: Expecting value: line 1 column 8 (char 7)

USER>set status = ##class(dc.Demo).ValidateJSON("{""aa"": true}") do:'status $system.OBJ.DisplayError(status)

try this

set objectContext = ##class(Some.Class).%OpenId(123)
write ##class(Ens.Rule.Definition).EvaluateRules("Rule.ClassName",,objectContext)

The error on screen shot saying Access Denied, why do you think it's Timeout?

Check the amount of connection available for you, and how much connection you do

Not so much magic in it, if you already know how to read it, the content of XData is just a Stream, which can be used both ways. Just Write to it, and %Save it. And you will probably need to compile the class

Class Demo.Test
{

XData OpenAPI [ MimeType = application/json ]
{
}

ClassMethod Update()
{
    set xdata = ##class(%Dictionary.XDataDefinition).IDKEYOpen($ClassName(), "OpenAPI")
    do xdata.Data.Write("{}")
    do xdata.%Save()
}

}

In VSCode, the content of XData will not appear after that, because it happened on the server, and VSCode will not see the changes, you'll need to export it manually

@John Bradshaw Converted from comment to a separate question, please update the zversion which you using 

my tool irissqlci supports CTE (except recursive). As well as SQLAlchemy with SQLAlchemy-IRIS

You can read journal files from any instance, but using Journals API, not using management portal

34

ClassMethod Check(w As %String) As %Boolean [ Language = python ]
{
return len(w)==len(set(w.lower()))
}

Well, the issue is that Caché, or even IRIS, still uses one Job to process requests for the same session. So, anything higher than 1.1 will not help at all. So, the only solution is to make sure that as much more possible static files are processed without Caché/IRIS or WebGateway, through a webserver configured for HTTP/2/3. And only API requests which require data would go to Caché/IRIS, and best case if it will be session-less queries, meaning that your requests are not tied to the session on the server, and those queries could be processed in parallel, and everything needed can be reconstructed from the query, e.g. username to check permissions should go from Authorization header.

Moving from HTTP/1.1 to HTTP/2/3 is not as simple as you expect, differences between protocols are significant. And requires a lot of work on the application.

Well the current version of IPM allows to build and publish to some private registry deployed packages. 

So, for companies that would like to distribute their packages through IPM, they can install own registry provide authentication for users who bought their product, so they will be able to connect to the registry and install the package.

I'm sure that the best way to test REST API would be to use some external tools, such as Postman/newman

You can look at my example project, which contains running tests against REST using newman

But it also contains some tests for REST on the IRIS side

Another solution is to use getattr

classname="%SYSTEM.SYS"
methodname="ProcessID"
pid = getattr(iris.cls(classname), 'ProcessID')()

myerror=iris.cls("%Exception.PythonException")._New("MyOops",123,"def+123^XYZ","SomeData")
for propertyname in ["Name","Code","Data","Location"]:
    print(getattr(myerror, propertyname))