[Opensim-dev] Adding an assembly reference to make available via script

[J Lothian]

I'm not so sure that the current setup includes the System namespace.  The
only assembly, other than the OpenSim specific ones, that is loaded is
System.Collections.Generic.  I had to add System before I could even use
Exceptions, which seems to indicate that only parts of System that are
pulled in are the parts used by the other assemblies that are loaded.

Melanie's response (which I mostly agree with) is why I didn't post it on
the Wiki.  This isn't something the average user (specifically OpenGrid
users) should probably be doing.  But rather than saying "absolutely not", I
have to wonder if there's some reasonable middle ground that can do the job
of both 1) protecting the average installation from arbitrary library code
inclusion/execution, and 2) allowing an easier way to include that facility,
for users that -do- need it, as a way for others to make OpenSim more
flexible.

Compile-time isn't a show-stopper, but something that makes the process
easier, like a module, or something in the build system/environment like an
"scriptengine_additional_libraries" variable might be handy.  Basically,
narrowing down a potential point of failure to one place, instead of three.

Thanks again though, my team here really appreciates all the hard work you
all put into this.

--Jeremy Lothian

On Thu, May 27, 2010 at 8:11 PM, Justin Clark-Casey <
jjustincc at googlemail.com> wrote:

> Melanie wrote:
>
>> A generic means to add extra libs would be highly DANGEROUS. It
>> definitely needs to be compile-time. Probably has to be, anyway,
>> from the way the scripts work.
>>
>
> C# scripts are insecure anyway since anybody who can create them has access
> to the System namespaces.  They are still useful in contexts where script
> creation and editing are restricted or all parties are highly trusted.
>
>
>
>> Melanie
>>
>> Justin Clark-Casey wrote:
>>
>>> J Lothian wrote:
>>>
>>>> Justin,
>>>>  Thanks for pointing me in a direction, this was -very- helpful.  It
>>>> wasn't nearly as straightforward as I was expecting, but it did give me the
>>>> opportunity/excuse to get my hands dirty and dig into the projects and code
>>>> a bit.  I'm going to document the process a bit here, so it gets archived
>>>> for future reference.  I'm pretty sure I've narrowed down the steps needed.
>>>> The actual project that needs the assembly reference added to it is
>>>> OpenSim.Region.ScriptEngine.Shared.CodeTools, but this is just the start.
>>>>  This gets the assembly detectable by the compiler.  The next step is adding
>>>> the reference to the script being compiled.  In
>>>> OpenSim.Region.ScriptEngine.Shared.CodeTools.Compiler (Compiler.cs), in the
>>>> function CompileFromDotNetText, there is a section where
>>>> ReferencedAssemblies are added to the compiler as parameters, and the
>>>> assembly needs to be added here as well.  For example, to add a standard
>>>> library, the following line would be used:
>>>>  parameters.ReferencedAssemblies.Add("System.dll");
>>>>  Which, it turns out, I needed to do, as System.dll isn't added by
>>>> default, and our test script included a try/catch where Exception was not
>>>> detected as a type.  To add something like the MySql dll that comes with
>>>> OpenSim, it would look like this:
>>>>
>>>> parameters.ReferencedAssemblies.Add(
>>>>
>>>> Path.Combine(rootPath,"MySql.Data.dll"));The script engine automatically
>>>> wraps scripts in boilerplate code to put them inside a class and make them
>>>> compilable.  This has the side-effect of making "using" or "import"
>>>> statements inside scripts impossible, so these also need to be added to the
>>>> code. For example, if your script is C#, then the function to alter is
>>>> CreateCSCompilerScript (in the same Compile.cs), adding the using statement
>>>> to the list inside this function.
>>>>  If I get the chance later this summer, I may try to develop a more
>>>> robust system that attempts to (at the very least) detect the default
>>>> mono/.net libraries and automatically adjust this boilerplate to include
>>>> them...
>>>>  Again, thanks for the help!
>>>>
>>> Glad that was of some use!  Would very much look forward to a boilerplate
>>> adjuster - being able to include extra libraries from OpenSim C# 'scripts'
>>> would be really useful.
>>>
>>> Also, it would be great if you could copy the above into a new wiki page
>>> off http://opensimulator.org/wiki/Developer_Documentation#Scripting.
>>>  Things tend to stay a little bit more visible there.  Thanks!
>>>
>>> _______________________________________________
>> Opensim-dev mailing list
>> Opensim-dev at lists.berlios.de
>> https://lists.berlios.de/mailman/listinfo/opensim-dev
>>
>>
>
> --
> Justin Clark-Casey (justincc)
> http://justincc.org
> http://twitter.com/justincc
> _______________________________________________
>  Opensim-dev mailing list
> Opensim-dev at lists.berlios.de
> https://lists.berlios.de/mailman/listinfo/opensim-dev
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://opensimulator.org/pipermail/opensim-dev/attachments/20100527/65e626c9/attachment-0001.html>