1 #============================================================================ 

     2 #Name        : api.py 

     3 #Part of     : Helium 

     4 

     5 #Copyright (c) 2009 Nokia Corporation and/or its subsidiary(-ies).

     6 #All rights reserved.

     7 #This component and the accompanying materials are made available

     8 #under the terms of the License "Eclipse Public License v1.0"

     9 #which accompanies this distribution, and is available

    10 #at the URL "http://www.eclipse.org/legal/epl-v10.html".

    11 #

    12 #Initial Contributors:

    13 #Nokia Corporation - initial contribution.

    14 #

    15 #Contributors:

    16 #

    17 #Description:

    18 #===============================================================================

    19 

    20 import logging

    21 logger = logging.getLogger("datasources.api")

    22 

    23 class MissingProperty(Exception):

    24     """ An exception to indicate about a missing property """

    25     pass

    26 

    27 class DataSource(object):

    28     """ This abstract class defines a DataSource for the packager application. """

    29     def __init__(self, epocroot, data=None):

    30         self.epocroot = epocroot

    31         self._data = data

    32         if data is None:

    33             self._data = {}

    34             

    35     def getComponents(self):

    36         """ The getComponents method must return a list of BuildData object (one per component).

    37             In case of error (e.g incomplete configuration) the method will raise an Exception.

    38         """

    39         raise NotImplementedError 

    40 

    41     def getHelp(self):

    42         return None

    43     

    44     help = property(lambda self: self.getHelp())

    45 

    46 

    47 DATASOURCES = {}

    48 

    49 def getDataSource(name, epocroot, data):

    50     if name in DATASOURCES:

    51         logger.debug("Creating datasource for %s." % name) 

    52         return DATASOURCES[name](epocroot, data)

    53     else:

    54         logger.info("Loading %s." % name)

    55         def class_import(name):

    56             try:

    57                 components = name.split('.')

    58                 klassname = components.pop()

    59                 mod = __import__('.'.join(components), globals(), locals(), [klassname])

    60                 return getattr(mod, klassname)

    61             except:

    62                 raise Exception("Could not load %s" % name)

    63         return class_import(name)(epocroot, data)

    64 

    65 

    66 def getDataSourceHelp():

    67     doc = ""

    68     for name in DATASOURCES:

    69         dshelp = DATASOURCES[name](None, None).help

    70         if dshelp is not None:

    71             doc = doc + "--- %s -----------------------------------\n" % name + dshelp +\

    72                     "\n------------------------------------------\n"

    73     return doc