It's a valid sample. You just can't write directly into ZEN context. Well, you can, obviously, but that causes errors.

Where exactly in samples?

Try commenting out all write statements in sqlTest method.

You can use RESTForms. It supplies converting object-to-JSON and JSON-to-object.

1. https certificate would apply to the cache and csp sites defined under IIS.  It would apply  to everyrhing really.

2. Not sure about html landing page being a security threat. That depends on your setup. Do you embed http parts in your (future) https pages?

I'd recommend as a first step to install let's encrypt certificate - it's free and easy.

Then force http->https redirect on your iis server.

After that check how your html landing page behaves.

I'm not raising exceptions, but rather do logging. Here's the article.

Thank you! That's very useful.

Is there a way to return real implementation class?

For example, consider these classes:

Class App.Use {

ClassMethod Test()
{
    w 1/0
}
}

and:

Class App.Use2 Extends App.Use
{
}

If I call:

do ##class(App.Use2).Test()

I get  the following CLS source line:

App.Use2:Test+1

Yet, the relevant code is actually implemented in

App.Use:Test+1

One approach I see is checking %Dictionary.MethodDefinition recursively till I find a method definition, but there's bound to be many problems multiple inheritance.

I don't understand your question. Please elaborate on the following points:

1. Do you want to create arbitrary relationships programmatically at design time (possible) or at runtime (not really)?
2. What difficulties in managing relationships you have encountered?
3. Can you provide some mock code demonstrating what you want to achieve?

Documentation.

Use TO_DATE SQL function.

You can set PasswordValidationRoutine in  the Security.System class. When a user is created in the Cache security database, or a user changes their password, the specified routine is called to validate the password. A tag reference may also be included in the property. The routine should be provided by the user, and must exist in the %SYS namespace (it may be mapped to a different database however.) The routine will take 2 parameters, a Username and new password, and should return a %Status code of $$$OK for successful password validation, or an error code formatted into a %Status variable. The username passed into the function will be in all lowercase, and will contain the domain name if multiple domains are enabled for the system.
 

Allowing client to specify server-side is not a recommended approach.

"C:\"_%request.MimeData("FileStream",1).FileName

Use incremented integers, hashes or guids instead.

Can you also post OnResponse1 method of FCH.BPL.PATWISJSONEPICXML.Context class?