How to use and install the embedPython module :

REQUIREMENTS:
=============

This module requires the Python-devel package, it has been tested with the 2.7 
version of the interpreter.

http://www.python.org

The module needs the PyRods Api which wraps the C Api of the iRods server. It is 
possible to remove this dependency if you parse the msParam_t parameters in the 
C microservice and pass the string or integer parameter when you call the 
Python method. It needs the Pyrods 3.0.0 version.

http://code.google.com/p/irodspython/
  

INSTALLATION:
=============

- Expand the package in the modules directory of the iRODS installation

- Adapt the Makefile to match your current directories and paths for the different
  libraries and object files. 
  
- Enable the microservice with the 'enabled' parameter in the info.txt file. You
  can also have to do a `./scripts/configure --enable-embedPython` in the iRODS
  root directory.

- Run `make` in the iRODS root directory and hopefully you will only have warnings
  and no errors.
  
- You will have to rebuild PyRods as object files are statically linked. (You will
  have to remove irods.so if you want to force the linking step)
  
USAGE:
======

- In the test directory of the module there are a set of test files that can be 
  used to check that the installation is working.
  
- the *.ir files have to be called with the `irule -vF test*.ir` command, the 
  results are either on the command line output or with local webmail (check the
  python code)
  
* The rule workflows have to begin with the msiPyInitialize microservice and end
  with the msiPyFinalize microservice. The interpreter is common between each
  steps meaning that you can pass parameters between steps via the global dict.
  
- All files call methods which are present in the process.py file, the path of
  the script is given as the first parameter of the microservice, the second
  parameter is the method name, the third one is the rule name. The remaining 
  parameters are the actual parameters of the python method.
  
- The naming convention for the different available microservices (msiLocal, 
  msiLocal1, msiRods1, ...) reflects the number of parameters in the python 
  scripts.
  
- The embedLocal* microservives takes as parameter a path of the script in the
  local filesystem of the server;
  
- The embedRods*  microservives takes as parameter a path of the script in iRODS
  
- The last parameter of the python script (not counted in the naming convention)
  corresponds to the ruleExecInfo_t parameter of microservices.    
  
- The parameters can be casted to strings or int with these calls : 
     * param.parseForPosInt()
     * param.parseForStr()
     
- The output parameters are returned with these calls :
     * fillIntInMsParam(param, 10)
     * fillStrInMsParam(param, "output")
     
- The msiExecPython microservice execute a python string code. It can be used 
  for instance to define variables or functions in the interpreter.
  
  
ISSUES :
========

- If you get USER_FILE_DOES_NOT_EXIST error, this should probably means that
  the module was not able to load the script which contains microservices. It's
  probably that the path to your python script does not exist or that there is 
  a syntax error (like indent problem).
  
- If you get NO_MICROSERVICE_FOUND_ERR error, this means that the module was not
  able to find the python microservice in the script you selected. Check the
  function name of the call (the second parameter in msiLocalPython...)
  
- If you get INVALID_OBJECT_TYPE error, this means that the CallFunction of the
  C Api failed. This happens for instance if the syntax of the python microservice
  is wrong or if you use undefined variables. The traceback should be printed
  in the rodsLog logfile with more precise information.