submodule: Fleshed out interface, and a partial test which is not yet usable. It showed that the ConfigParser needs some work. If the root is set, it also needs to refer to the root_commit instead of to the root-tree, as it will have to decide whether it works on the working tree's version of the .gitmodules file or the one in the repository

4 files changed, 139 insertions, 30 deletions

diff --git a/lib/git/config.py b/lib/git/config.py
index 09bad0b6..e919838b 100644
--- a/lib/git/config.py
+++ b/lib/git/config.py
@@ -15,7 +15,7 @@ import cStringIO
 from git.odict import OrderedDict
 from git.util import LockFile
 
-__all__ = ('GitConfigParser', )
+__all__ = ('GitConfigParser', 'SectionConstraint')
 
 class MetaParserBuilder(type):
 	"""Utlity class wrapping base-class methods into decorators that assure read-only properties"""
@@ -63,7 +63,29 @@ def set_dirty_and_flush_changes(non_const_func):
 	flush_changes.__name__ = non_const_func.__name__
 	return flush_changes
 	
+
+class SectionConstraint(object):
+	"""Constrains a ConfigParser to only option commands which are constrained to 
+	always use the section we have been initialized with.
+	
+	It supports all ConfigParser methods that operate on an option"""
+	__slots__ = ("_config", "_section_name")
+	_valid_attrs_ = ("get_value", "set_value", "get", "set", "getint", "getfloat", "getboolean", "has_option")
 	
+	def __init__(self, config, section):
+		self._config = config
+		self._section_name = section
+		
+	def __getattr__(self, attr):
+		if attr in self._valid_attrs_:
+			return lambda *args, **kwargs: self._call_config(attr, *args, **kwargs)
+		return super(SectionConstraint,self).__getattribute__(attr)
+		
+	def _call_config(self, method, *args, **kwargs):
+		"""Call the configuration at the given method which must take a section name 
+		as first argument"""
+		return getattr(self._config, method)(self._section_name, *args, **kwargs)
+		
 
 class GitConfigParser(cp.RawConfigParser, object):
 	"""Implements specifics required to read git style configuration files.
diff --git a/lib/git/ext/gitdb b/lib/git/ext/gitdb
-Subproject 78665b13ff4125f4ce3e5311d040c027bdc92a9
+Subproject 2ddc5bad224d8f545ef3bb2ab3df98dfe063c5b
diff --git a/lib/git/objects/submodule.py b/lib/git/objects/submodule.py
index 1f571a48..b0fd0e35 100644
--- a/lib/git/objects/submodule.py
+++ b/lib/git/objects/submodule.py
@@ -1,4 +1,8 @@
 import base
+from cStringIO import StringIO
+from git.config import GitConfigParser
+from git.util import join_path_native
+from git.exc import InvalidGitRepositoryError, NoSuchPathError
 
 __all__ = ("Submodule", )
 
@@ -7,10 +11,115 @@ class Submodule(base.IndexObject):
 	represents a commit in the submodule's repository which is to be checked out
 	at the path of this instance. 
 	The submodule type does not have a string type associated with it, as it exists
-	solely as a marker in the tree and index"""
+	solely as a marker in the tree and index.
+	
+	All methods work in bare and non-bare repositories."""
+	
+	kModulesFile = '.gitmodules'
 	
 	# this is a bogus type for base class compatability
 	type = 'submodule'
 	
-	# TODO: Add functions to retrieve a repo for the submodule, to allow 
-	# its initiailization and handling
+	__slots__ = ('_root_tree', '_url', '_ref')
+	
+	def _set_cache_(self, attr):
+		if attr == 'size':
+			raise ValueError("Submodules do not have a size as they do not refer to anything in this repository")
+		elif attr == '_root_tree':
+			# set a default value, which is the root tree of the current head
+			self._root_tree = self.repo.tree()
+		elif attr in ('path', '_url', '_ref'):
+			reader = self.config_reader()
+			# default submodule values
+			self._path = reader.get_value('path')
+			self._url = reader.get_value('url')
+			# git-python extension values - optional
+			self._ref = reader.get_value('ref', 'master')
+		else:
+			super(Submodule, self)._set_cache_(attr)
+		# END handle attribute name
+	
+	def _fp_config(self):
+		""":return: Configuration file as StringIO - we only access it through the respective blob's data"""
+		return StringIO(self._root_tree[self.kModulesFile].datastream.read())
+		
+	def _config_parser(self, read_only):
+		""":return: Config Parser constrained to our submodule in read or write mode"""
+		parser = GitConfigParser(self._fp_config(), read_only = read_only)
+		return SectionConstraint(parser, 'submodule "%s"' % self.path)
+		
+	#{ Edit Interface
+	
+	@classmethod
+	def add(cls, repo, path, url, skip_init=False):
+		"""Add a new submodule to the given repository. This will alter the index
+		as well as the .gitmodules file, but will not create a new commit.
+		:param repo: Repository instance which should receive the submodule
+		:param path: repository-relative path at which the submodule should be located
+			It will be created as required during the repository initialization.
+		:param url: git-clone compatible URL, see git-clone reference for more information
+		:param skip_init: if True, the new repository will not be cloned to its location.
+		:return: The newly created submodule instance"""
+		
+	def set_root_tree(self, root_tree):
+		"""Set this instance to use the given tree which is supposed to contain the 
+		.gitmodules blob.
+		:param root_tree: Tree'ish reference pointing at the root_tree
+		:raise ValueError: if the root_tree didn't contain the .gitmodules blob."""
+		tree = self.repo.tree(root_tree)
+		if self.kModulesFile not in tree:
+			raise ValueError("Tree %s did not contain the %s file" % (root_tree, self.kModulesFile))
+		# END handle exceptions
+		self._root_tree = tree
+		
+		# clear the possibly changing values
+		del(self.path)
+		del(self._ref)
+		del(self._url)
+		
+	def config_writer(self):
+		""":return: a config writer instance allowing you to read and write the data
+		belonging to this submodule into the .gitmodules file."""
+		return self._config_parser(read_only=False)
+		
+	#} END edit interface
+	
+	#{ Query Interface
+	
+	def module(self):
+		""":return: Repo instance initialized from the repository at our submodule path
+		:raise InvalidGitRepositoryError: if a repository was not available"""
+		if self.repo.bare:
+			raise InvalidGitRepositoryError("Cannot retrieve module repository in bare parent repositories")
+		# END handle bare mode
+		
+		repo_path = join_path_native(self.repo.working_tree_dir, self.path)
+		try:
+			return Repo(repo_path)
+		except (InvalidGitRepositoryError, NoSuchPathError):
+			raise InvalidGitRepositoryError("No valid repository at %s" % self.path)
+		# END handle exceptions
+		
+	def ref(self):
+		""":return: The reference's name that we are to checkout"""
+		return self._ref
+		
+	def url(self):
+		""":return: The url to the repository which our module-repository refers to"""
+		return self._url
+	
+	def root_tree(self):
+		""":return: Tree instance referring to the tree which contains the .gitmodules file
+		we are to use
+		:note: will always point to the current head's root tree if it was not set explicitly"""
+		return self._root_tree
+	
+	def config_reader(self):
+		""":return: ConfigReader instance which allows you to qurey the configuration values
+		of this submodule, as provided by the .gitmodules file
+		:note: The config reader will actually read the data directly from the repository
+			and thus does not need nor care about your working tree.
+		:note: Should be cached by the caller and only kept as long as needed"""
+		return self._config_parser.read_only(read_only=True)
+		
+	#} END query interface
diff --git a/lib/git/remote.py b/lib/git/remote.py
index 52dd787d..135e37d7 100644
--- a/lib/git/remote.py
+++ b/lib/git/remote.py
@@ -7,7 +7,8 @@
 
 from exc import GitCommandError
 from objects import Commit
-from ConfigParser import NoOptionError 
+from ConfigParser import NoOptionError
+from config import SectionConstraint
 
 from git.util import (
 						LazyMixin,
@@ -30,29 +31,6 @@ import os
 
 __all__ = ('RemoteProgress', 'PushInfo', 'FetchInfo', 'Remote')
 
-class _SectionConstraint(object):
-	"""Constrains a ConfigParser to only option commands which are constrained to 
-	always use the section we have been initialized with.
-	
-	It supports all ConfigParser methods that operate on an option"""
-	__slots__ = ("_config", "_section_name")
-	_valid_attrs_ = ("get_value", "set_value", "get", "set", "getint", "getfloat", "getboolean", "has_option")
-	
-	def __init__(self, config, section):
-		self._config = config
-		self._section_name = section
-		
-	def __getattr__(self, attr):
-		if attr in self._valid_attrs_:
-			return lambda *args, **kwargs: self._call_config(attr, *args, **kwargs)
-		return super(_SectionConstraint,self).__getattribute__(attr)
-		
-	def _call_config(self, method, *args, **kwargs):
-		"""Call the configuration at the given method which must take a section name 
-		as first argument"""
-		return getattr(self._config, method)(self._section_name, *args, **kwargs)
-		
-		
 class RemoteProgress(object):
 	"""
 	Handler providing an interface to parse progress information emitted by git-push
@@ -449,7 +427,7 @@ class Remote(LazyMixin, Iterable):
 	
 	def _set_cache_(self, attr):
 		if attr == "_config_reader":
-			self._config_reader = _SectionConstraint(self.repo.config_reader(), self._config_section_name())
+			self._config_reader = SectionConstraint(self.repo.config_reader(), self._config_section_name())
 		else:
 			super(Remote, self)._set_cache_(attr)
 			
@@ -735,4 +713,4 @@ class Remote(LazyMixin, Iterable):
 		
 		# clear our cache to assure we re-read the possibly changed configuration
 		del(self._config_reader)
-		return _SectionConstraint(writer, self._config_section_name())
+		return SectionConstraint(writer, self._config_section_name())