[IronPython] Embedding IronPython and calling python functions from C#

[Michael Foord]

Patrick van der Willik wrote:
> Alright, that actually really worked pretty good, and I finally got it 
> all working as it should. However, I'm running into 1 more little 
> issue, now I need to go the other way around aswell. I have several 
> functions marked in my application as PythonExportable. In a certain 
> startup phase of the application, after creating the IronPython 
> hosting environment, I walk over all these classes using Reflection, 
> take the tagged functions and put these into my IP scope.
>
> However, my simple tests for some reason cause my SetVariable() calls 
> to not work. I added 2 tests to my scripts, one where I add a variable 
> into the scope and another one where I add a delegate. However, in 
> both cases, whenever I use these variables from within my scripts, 
> they don't seem to work. Code:
>                Func<string> test = new Func<string>(Test);
>                scope.SetVariable("x", 10);
>                scope.SetVariable("Test", test);
>
> Accessing them in my scripts have the effect of triggering an 
> exception that shows that x is undefined.

Can you show the actual code that attempts to use them and the actual 
exception message raised.

Michael

>
> Some insights into this would be of great help.
>
> Patrick
>
> Michael Foord wrote:
>> See this section of my hosting article:
>>
>> http://www.voidspace.org.uk/ironpython/hosting_api.shtml#functions-as-delegates 
>>
>>
>> You cast the function to a delegate as you fetch it out of the scope.
>>
>> Michael
>>
>> Patrick van der Willik wrote:
>>> I'm a bit late with responding to this as I was kinda busy. I used 
>>> the code that was given Stephen and it seems to run properly without 
>>> throwing exceptions. However, I created a little autoexec.py file 
>>> with a simple function in it with 2 parameters.
>>>
>>> The main problem here is: How do I call the function through the 
>>> scope? I used engine.CreateScope() to create myself a new scope, but 
>>> from there on, I'm basically lost(again). What I basically want to 
>>> do, is call my function 'add' with 2 parameters(say, 10 and 15). The 
>>> modules itself are loaded into a ScriptSource.
>>>
>>> Thanks,
>>> Patrick
>>>
>>> Lepisto, Stephen P wrote:
>>>>
>>>> What I do when I want to work with python modules from embedded 
>>>> IronPython is set the IronPython search path with the path of the 
>>>> module to load then  create and execute a small python script that 
>>>> loads the main python modules into the current scope.
>>>>
>>>>  
>>>>
>>>> string moduleName = Path.GetFileName(modulePath);
>>>>
>>>> string path = Path.GetDirectoryName(modulePath);
>>>>
>>>>  
>>>>
>>>> ICollection<string> paths = _pythonEngine.GetSearchPaths();
>>>>
>>>> if (!paths.Contains(path))
>>>>
>>>> {
>>>>
>>>>     paths.Add(path);
>>>>
>>>>     _pythonEngine.SetSearchPaths(paths);
>>>>
>>>> }
>>>>
>>>> string modInvoke = String.Format("import {0}\nfrom {0} import *\n", 
>>>> moduleName);
>>>>
>>>> ScriptSource source = 
>>>> _pythonEngine.CreateScriptSourceFromString(modInvoke,
>>>>
>>>>                                                                  
>>>> Microsoft.Scripting.SourceCodeKind.Statements);
>>>>
>>>>  
>>>>
>>>> Where modulePath is the full path to the python module or package 
>>>> to load.
>>>>
>>>>  
>>>>
>>>> I can then invoke methods or access attributes using the IronPython 
>>>> scope.  In this way, I can interact with the python modules for as 
>>>> long as necessary before closing down the scope/engine.
>>>>
>>>>  
>>>>
>>>>  
>>>>
>>>> *From:* users-bounces at lists.ironpython.com 
>>>> [mailto:users-bounces at lists.ironpython.com] *On Behalf Of *Dody 
>>>> Gunawinata
>>>> *Sent:* Thursday, June 11, 2009 9:09 AM
>>>> *To:* Discussion of IronPython
>>>> *Subject:* Re: [IronPython] Embedding IronPython and calling python 
>>>> functions from C#
>>>>
>>>>  
>>>>
>>>> You can read all yours file scripts, then using StringBuilder to 
>>>> combine then and call CreateScriptSourceFromString()
>>>>
>>>> Then you can call your functions within the combined scripts 
>>>> normally. Pretty much you are creating a giant source code on the fly.
>>>>
>>>>  
>>>>
>>>> On Thu, Jun 11, 2009 at 5:32 PM, Patrick van der Willik 
>>>> <patrick at toolmaker.nl <mailto:patrick at toolmaker.nl>> wrote:
>>>>
>>>> I'm currently attempting to embed the IronPython 2 runtimes into an 
>>>> existing application written in C#. However, I find the amount of 
>>>> documentation lacking on what I'm trying to do. I currently have a 
>>>> proof-of-concept version which uses Lua and LuaInterface, but the 
>>>> people who have to write the scripts dislike Lua(Well, more hate it 
>>>> with a passion) and would love to see this working with Python.
>>>>
>>>> My host application is a networked application that must trigger 
>>>> certain scripts functions on events generated by the connected 
>>>> clients. The idea is that when my application starts, it will load 
>>>> the IronPython script environment, launches an 'autoexec.py' which 
>>>> will load various other scripts files and do some housekeeping. 
>>>> Once this all is completed, it will start listening to incoming 
>>>> connections. However, in various scenarios, the application has to 
>>>> trigger scripted functions when data is received from a client. 
>>>> Which script function is called is different per client and per 
>>>> event. I have events for connecting, logging on, disconnecting and 
>>>> a set of data specific events after receiving data. This highly 
>>>> depends on the received packets.
>>>>
>>>> My question here is: How do I embed IronPython in such a fashion 
>>>> that I can load my scripts and then trigger various functions 
>>>> within that? I've seen many examples that just call 
>>>> CreateScriptSourceFromString() or File each time in which just 1 
>>>> piece of code is implemented. This is not suitable for the needs 
>>>> here because the scripted systems can become quite complex.
>>>>
>>>> With regards,
>>>> Patrick
>>>>
>>>>
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>>>>
>>>>
>>>>
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