Postconditionals are to be used only for the most simple checks, for example:

set:a="" a=10

instead of

if a="" {
  set a=10
}

But several conditions (or several lines inside) should be as if, I agree.

For one-line if I prefer postconditionals:

set:a b=a

As for For - the option with braces. It's more readable. And one line inside For loop quickly and often becomes several lines, so braces become mandatory anyway.

Why do you need to check it at runtime? If source and target are from different but related  classes you can copy by their common ancestor (or by specified ancestor class). Or do you copy properties between two unrelated classes?

Nice example of using method generators.

Why do you need ExistsProperty? Here's a check I usually employ for class properties in generators:

 if prop.Internal || prop.Calculated || prop.ReadOnly || prop.Private || prop.Identity || prop.MultiDimensional  CONTINUE

It filters out all systems properties like Concurrency, %%OID and so on.

When talking about speed, one of the most important questions is what exactly do you need to speed up? You need to determine:

• what queries are the most popular
• what queries take the most time

to fix it. Some ways to fix performance are (easy to hard):

• Add indices
• Change classes
• Change application architecture

Because in your case I see at least two request types which require different actions to speed them up:

• Get last X changes
• Get last X modified subjects

Versioning for example. Temporal queries and so on.

Header itself is another layer because it's meta information for the BPL state machine, which you're inside of. So I don't see how you can get header Id from inside the state machine without violating abstractions in place.

Still, %Context, %Process and %LastError are documented and acceptable to use.

You can access %Ensemble("%Process") as ..%Process so:

..%Process.%PrimaryRequestHeader.%Id()

Reference WebDAV implementation for Caché.

Check out Caché FileServer project for a sample of file upload/download.

Use any of the existing Git hooks for Studio or Atelier.  They would work with GitHub and GitLab both.

Check EvaluateRules method of Ens.Rule.Definition class. It evaluates rule by name and context. You can call it from Studio or Terminal.

Got it. Usually after enabling HTTPS I add server-wide redirect from HTTP to HTTPS. So in cube I specify port 80 and it automatically redirects to HTTPS.

HTTPS access is implemented and easily configurable.

If Caché does not work through IIS, you need to configure it.  On Windows you can configure Caché to work with IIS, Apache or Nginx.

After you have configured the web server to work with Caché, add https support.  For example use Let's encrypt as a CA.

You can use DATEPART function:

w $SYSTEM.SQL.DATEPART("year", $h)
>2018
w $SYSTEM.SQL.DATEPART("month", $h)
>1

The advantage of this approach is more readable code.

Learning.intersystems.com has a lot of courses you can access for free. They start right from the basics.

while i was using your code, i am getting this error in response, which says "read" method is unknown

You're getting this error because list of objects does not have this method. Check your list of objects for contents. Seems like json is already converted so you don't need to do that.