sfa/rspecs/version_manager.py

   1 import os
   2
   3 class VersionManager:
   4     default_type = 'SFA'
   5     default_version_num = '1'
   6
   7     def __init__(self):
   8         self.versions = []
   9         self.load_versions()
  10
  11     def load_versions(self):
  12         path = os.path.dirname(os.path.abspath( __file__ ))
  13         versions_path = path + os.sep + 'versions'
  14         versions_module_path = 'sfa.rspecs.versions'
  15         valid_module = lambda x: os.path.isfile(os.sep.join([versions_path, x])) \
  16                         and not x.endswith('.pyc') and x not in ['__init__.py']
  17         files = [f for f in os.listdir(versions_path) if valid_module(f)]
  18         for filename in files:
  19             basename = filename.split('.')[0]
  20             module_path = versions_module_path +'.'+basename
  21             module = __import__(module_path, fromlist=module_path)
  22             for attr_name in dir(module):
  23                 attr = getattr(module, attr_name)
  24                 if hasattr(attr, 'version'):
  25                     self.versions.append(attr)
  26
  27     def _get_version(self, type, version_num=None, content_type=None):
  28         retval = None
  29         for version in self.versions:
  30             if type is None or type.lower() == version.type.lower():
  31                 if version_num is None or version_num == version.version:
  32                     if content_type is None or content_type.lower() == version.content_type.lower():
  33                         retval = version
  34         if not retval:
  35             raise Exception, "No such version format: %s version: %s type:%s "% (type, version_num, content_type)
  36         return retval
  37
  38     def get_version(self, version):
  39         retval = None
  40         if isinstance(version, dict):
  41             retval =  self._get_version(version.get('type'), version.get('version_num'), version.get('content_type'))
  42         elif isinstance(version, basestring):
  43             version_parts = version.split(' ')
  44             num_parts = len(version_parts)
  45             type = version_parts[0]
  46             version_num = None
  47             content_type = None
  48             if num_parts > 1:
  49                 version_num = version_parts[1]
  50             if num_parts > 2:
  51                 content_type = version_parts[2]
  52             retval = self._get_version(type, version_num, content_type)
  53         else:
  54             logger.info("Unable to parse rspec version, using default")
  55             retval = self._get_version(self.default_type, self.default_version_num)
  56
  57         return retval
  58
  59 if __name__ == '__main__':
  60     v = VersionManager()
  61     print v.versions
  62     print v.get_version('sfa 1')
  63     print v.get_version('protogeni 2')
  64     print v.get_version('protogeni 2 advertisement')
  65
  66