Le 09/06/2012 13:53, Jacques Le Roux a écrit :
From: "Adrian Crum" <adrian.c...@sandglass-software.com>
I'm working on the Mini-language <set-current-user-login> element,
and I wanted some feedback about this TYPE of operation.
Background: There are some things in the Mini-language script
execution context that, from my perspective, should be read-only.
Some of those things are the delegator and security credentials
(there are others - see SimpleMethod.java, line 85). From a scripting
standpoint, I believe it helps the developer if those things are
constant or immutable, and provide a means to override them
explicitly in certain circumstances. In other words, the scripting
language should be designed in a way that facilitates writing good
scripts.
Giving the developer the ability to override those things opens up
the potential for quirky and possibly unsafe code. Changing the
delegator or user credentials mid-script might seem convenient at
first glance, but it becomes a debugging and code maintenance
nightmare later on. There is a better way to handle the need to use
different artifacts during script execution. For example, instead of
changing the script's delegator, entity operations could support
specifying the delegator to use. The explicit use of an alternate
delegator is easier to understand and debug than a delegator change
that occurred somewhere else in the script execution path (a path
that might include other simple methods).
The same thing could be done for security credentials. The
Mini-language schema says the <set-current-user-login> element "...is
mostly used for calling services, etc" - but you can provide an
alternate UserLogin to the service via the IN attributes. Therefore,
that element is not necessary.
A lot of existing Mini-language code performs those mid-script
artifact changes, so this isn't something that can be changed
overnight. What I propose is a "best practice" where that type of
operation is discouraged in the Mini-language documentation. Maybe in
a future version of the grammar, elements of that type can be
deprecated.
What do you think?
Those ideas seem sound and well founded to me. We could already
deprecate <set-current-user-login> since we can pass the login. We
have to make those changes very explicit though. Normally this one
(<set-current-user-login>) is known anyway...
+1
min-language should be usefull for all "classical" operations,
<set-current-user-login> is not "classical" and the developer which want
to use it should know that he can do that by providing UserLogin to the
service via the IN attributes. So +1 to already deprecated it.
Jacques
-Adrian
