[Modeling-cvs] ProjectModeling/Modeling Model.py,1.4.2.1,1.4.2.2

[<sbi...@us...>]

Update of /cvsroot/modeling/ProjectModeling/Modeling
In directory sc8-pr-cvs1:/tmp/cvs-serv4177

Modified Files:
      Tag: brch-0_9pre7-1-PyModel
	Model.py 
Log Message:
Added updateModelWithCFG(), loadModel(), searchModel()

Index: Model.py
===================================================================
RCS file: /cvsroot/modeling/ProjectModeling/Modeling/Model.py,v
retrieving revision 1.4.2.1
retrieving revision 1.4.2.2
diff -C2 -d -r1.4.2.1 -r1.4.2.2
*** Model.py	15 May 2003 17:44:20 -0000	1.4.2.1
--- Model.py	17 Jun 2003 16:55:54 -0000	1.4.2.2
***************
*** 49,52 ****
--- 49,236 ----
    from Persistent import Persistent
  
+ def updateModelWithCFG(model, cfg_path=None):
+   """
+   Updates the model's connection dictionary and adaptorName with the values
+   in file 'cfg_path'. If cfg_path is omitted or None, the value stored
+   in the environment variable MDL_DB_CONNECTIONS_CFG is used instead.
+ 
+   A sample configuration file is like::
+ 
+     [DEFAULT]
+     host: localhost
+ 
+     [ModelName_1]
+     user: user_1
+     password: pwd_1
+ 
+     [ModelName_2]
+     adaptor: MySQL
+     user: user_2
+     password: pwd_2
+ 
+   The special field 'adaptor', if present, changes the adaptorName of the
+   model.
+ 
+   Raises IOError if file 'cfg_path' cannot be found.
+ 
+   See also: ModelSet.addModel()
+ 
+   Parameters:
+ 
+     model -- the model whose conn.dict. should be updated
+ 
+     cfg_path -- the full path to the configuration file, or if omitted or
+       None, defaults to the value stored in the env. variable
+       MDL_DB_CONNECTIONS_CFG
+     
+   """
+   import os
+   if cfg_path is None:
+     cfg_path=os.environ.get('MDL_DB_CONNECTIONS_CFG')
+ 
+   from ConfigParser import ConfigParser
+   defaults=model.connectionDictionary()
+   cp=ConfigParser()
+   try:
+     cp.readfp(open(cfg_path))
+   except IOError:
+     import traceback, cStringIO, sys
+     exc_raised=sys.exc_info()[:2]
+     err_msg="Unable to open file '%s' (passed in parameter 'cfg_path' or taken from env. variable MDL_DB_CONNECTIONS_CFG"%cfg_path
+     exc=cStringIO.StringIO()
+     traceback.print_exception(exc_raised[0], exc_raised[1], None, file=exc)
+     err_msg+="\nOriginal exception was: %s"%exc.getvalue()
+     raise IOError, err_msg
+ 
+   try: options=cp.options(model.name())
+   except: return
+   try: options.remove('adaptor')
+   except ValueError: pass
+   for key in options:
+     defaults[key]=cp.get(model.name(), key)
+   model.setConnectionDictionary(defaults)
+   try:
+     model.setAdaptorName(cp.get(model.name(), 'adaptor'))
+   except:
+     pass
+ 
+ def loadModel(path):
+   """
+   Load a model stored in the file 'path'. The lookup procedure is:
+ 
+     - if path ends with '.py', we assume it is a python module. This module is
+       imported and the following attributes are searched within it, in that
+       order:
+ 
+         1. 'model' (either an attribute or a function): if found, we assume
+            this is an instance of Modeling.Model.Model and we return the value
+ 
+         2. 'pymodel' (id.): if found, we assume this is an instance of
+            Modeling.PyModel.Model and we return its 'component' attribute
+ 
+         3. 'model_src' (id.): if found, we assume this is a string and return
+            the model build from it with ModelSet.addModelFromXML()
+         
+     - if path ends with '.xml', we assume this is a xml-file and we return the
+       model build with ModelSet.addModelFromXML()
+ 
+   Returns: the loaded Modeling.Model.Model instance
+ 
+   Raises IOError if file 'path' cannot be found
+ 
+   Parameter:
+ 
+     path -- the path of the file where the model is stored
+     
+   """
+   if path[-3:]=='.py':
+     import os,imp
+     dir,filename=os.path.dirname(path),os.path.basename(path)
+     modulename=filename[:-3]
+     file=None
+     try:
+       try:
+         file,pathname,description=imp.find_module(modulename, [dir])
+         module=imp.load_module(modulename,file,pathname,description)
+ 
+         if hasattr(module, 'model'):
+           model=module.model
+           if callable(model):
+             model=model()
+           updateModelWithCFG(model)
+           return model
+ 
+         if hasattr(module, 'pymodel'):
+           model=module.pymodel
+           if callable(pymodel):
+             pymodel=pymodel()
+           updateModelWithCFG(pymodel.component)
+           return pymodel.component
+         
+         if hasattr(module, 'model_src'):
+           model_src=module.model_src
+           if callable(model_src):
+             model_src=model_src()
+           from ModelSet import ModelSet
+           model=ModelSet().addModelFromXML({'string': model_src})
+           updateModelWithCFG(model)
+           return model
+         
+         raise IOError, "Couldn't find any of these attributes in python file '%s': model, pymodel (PyModel) or model_src (xml)"%path
+ 
+       except:
+         import cStringIO, traceback
+         exc=cStringIO.StringIO()
+         traceback.print_exc(file=exc)
+         raise IOError, 'Unable to handle python file %s\nReason: exception raised:\n%s'%(path,exc.getvalue())
+       
+     finally:
+       if file: file.close()
+   elif path[-4:]=='.xml':
+     from ModelSet import ModelSet
+     return ModelSet().addModelFromXML({'file': path})
+     
+   else:
+     raise IOError, 'Unable to load file %s'%path
+   
+ def searchModel(modelName, path=None, verbose=0):
+   """
+   Searches for the model named 'modelName' by trying loadModel() with the
+   following paths: 'pymodel_<modelName>.py', 'model_<modelName>.py' and
+   'model_<modelName>.xml' in the current directory and the MDL/ directory.
+   
+   Returns the model, or None if it cannot be found/loaded
+ 
+   """
+   if verbose:
+     import sys
+     mylog=lambda msg, stderr=sys.stderr:stderr.write('[Model.searchModel] %s\n'%msg)
+   else:
+     mylog=lambda msg: None
+ 
+   searchList=('pymodel_%s.py', 'model_%s.py', 'model_%s.xml',
+               'MDL/pymodel_%s.py', 'MDL/model_%s.py', 'MDL/model_%s.xml')
+   for file in searchList:
+     model=None
+     file=file%modelName
+     if path:
+       import os
+       file=os.path.join(path, file)
+     try:
+       mylog('Trying %s'%file)
+       model=loadModel(file)
+     except IOError:
+       import cStringIO, traceback
+       exc=cStringIO.StringIO()
+       traceback.print_exc(file=exc)
+       mylog('Not found: %s\n  Exception:%s'%(file,exc.getvalue()))
+       del exc
+       pass
+     if model:
+       return model
+     mylog('Not found: %s'%file)
+   mylog('modelName %s: All possibilities exhausted -- returning None'%modelName)
+   return None
+ 
  class Model(Persistent, XMLCapability, KeyValueCoding):
    "Describes a model"