sfa/rspecs/version_manager.py

   1 import os
   2 from sfa.util.sfalogging import logger
   3
   4 class VersionManager:
   5     default_type = 'SFA'
   6     default_version_num = '1'
   7
   8     def __init__(self):
   9         self.versions = []
  10         self.load_versions()
  11
  12     def load_versions(self):
  13         path = os.path.dirname(os.path.abspath( __file__ ))
  14         versions_path = path + os.sep + 'versions'
  15         versions_module_path = 'sfa.rspecs.versions'
  16         valid_module = lambda x: os.path.isfile(os.sep.join([versions_path, x])) \
  17                         and not x.endswith('.pyc') and x not in ['__init__.py']
  18         files = [f for f in os.listdir(versions_path) if valid_module(f)]
  19         for filename in files:
  20             basename = filename.split('.')[0]
  21             module_path = versions_module_path +'.'+basename
  22             module = __import__(module_path, fromlist=module_path)
  23             for attr_name in dir(module):
  24                 attr = getattr(module, attr_name)
  25                 if hasattr(attr, 'version'):
  26                     self.versions.append(attr)
  27
  28     def _get_version(self, type, version_num=None, content_type=None):
  29         retval = None
  30         for version in self.versions:
  31             if type is None or type.lower() == version.type.lower():
  32                 if version_num is None or version_num == version.version:
  33                     if content_type is None or content_type.lower() == version.content_type.lower():
  34                         retval = version
  35         if not retval:
  36             raise InvalidRSpec("No such version format: %s version: %s type:%s "% (type, version_num, content_type))
  37         return retval
  38
  39     def get_version(self, version=None):
  40         retval = None
  41         if isinstance(version, dict):
  42             retval =  self._get_version(version.get('type'), version.get('version_num'), version.get('content_type'))
  43         elif isinstance(version, basestring):
  44             version_parts = version.split(' ')
  45             num_parts = len(version_parts)
  46             type = version_parts[0]
  47             version_num = None
  48             content_type = None
  49             if num_parts > 1:
  50                 version_num = version_parts[1]
  51             if num_parts > 2:
  52                 content_type = version_parts[2]
  53             retval = self._get_version(type, version_num, content_type)
  54         else:
  55             logger.info("Unable to parse rspec version, using default")
  56             retval = self._get_version(self.default_type, self.default_version_num)
  57
  58         return retval
  59
  60     def get_version_by_schema(self, schema):
  61         retval = None
  62         for version in self.versions:
  63             if schema == version.schema:
  64                 retval = version
  65         if not retval:
  66             raise InvalidRSpec("Unkwnown RSpec schema: %s" % schema)
  67         return retval
  68
  69 if __name__ == '__main__':
  70     v = VersionManager()
  71     print v.versions
  72     print v.get_version('sfa 1')
  73     print v.get_version('protogeni 2')
  74     print v.get_version('protogeni 2 advertisement')
  75     print v.get_version_by_schema('http://www.protogeni.net/resources/rspec/2/ad.xsd')
  76