Added a recipe update method.

CHANGES.txt

@@ -28,7 +28,12 @@ Next Release
 Feature Changes
 ---------------
 
-Renamed the runsetup command to setup. (The old name still works.)
+- Renamed the runsetup command to setup. (The old name still works.)
+
+- Added a recipe update method. Now install is only called when a part
+  is installed for the first time, or after an uninstall. Otherwise, 
+  update is called.  For backward compatibility, recipes that don't
+  define update methiods are still supported.
 
 1.0.0b9 (2006-10-02)
 ====================

src/zc/buildout/buildout.py

@@ -288,10 +288,21 @@ class Buildout(dict):
             for part in reversed(installed_parts):
                 if part in install_parts:
                     old_options = installed_part_options[part].copy()
-                    old_options.pop('__buildout_installed__')
+                    installed_files = old_options.pop('__buildout_installed__')
                     new_options = self.get(part)
                     if old_options == new_options:
-                        continue
+                        # The options are the same, but are all of the
+                        # installed files still there?  If not, we should
+                        # reinstall.
+                        if not installed_files:
+                            continue
+                        for f in installed_files.split('\n'):
+                            if not os.path.exists(self._buildout_path(f)):
+                                break
+                        else:
+                            continue
+
+                    # output debugging info
                     for k in old_options:
                         if k not in new_options:
                             self._logger.debug("Part: %s, dropped option %s",
@@ -305,6 +316,7 @@ class Buildout(dict):
                         if k not in old_options:
                             self._logger.debug("Part: %s, new option %s",
                                                part, k)
+
                 elif not uninstall_missing:
                     continue
 
@@ -316,17 +328,52 @@ class Buildout(dict):
 
             # install new parts
             for part in install_parts:
-                self._logger.info('Installing %s', part)
-                installed_part_options[part] = self[part].copy()
-                del self[part]['__buildout_signature__']
-                installed_files = recipes[part].install() or ()
+                signature = self[part].pop('__buildout_signature__')
+                saved_options = self[part].copy()
+                if part in installed_parts:
+                    self._logger.info('Updating %s', part)
+                    old_options = installed_part_options[part]
+                    old_installed_files = old_options['__buildout_installed__']
+                    try:
+                        update = recipes[part].update
+                    except AttributeError:
+                        update = recipes[part].install
+                        self._logger.warning(
+                            "The recipe for %s doesn't define an update "
+                            "method. Using it's install method",
+                            part)
+                        
+                    try:
+                        installed_files = update()
+                    except:
+                        installed_parts.remove(part)
+                        self._uninstall(old_installed_files)
+                        raise
+                    
+                    if installed_files is None:
+                        installed_files = old_installed_files.split('\n')
+
+                else:
+                    self._logger.info('Installing %s', part)
+                    installed_files = recipes[part].install()
+                    if installed_files is None:
+                        self._logger.warning(
+                            "The %s install returned None.  A path or "
+                            "iterable os paths should be returned.",
+                            part)
+                        installed_files = ()
+                    
                 if isinstance(installed_files, str):
                     installed_files = [installed_files]
-                installed_part_options[part]['__buildout_installed__'] = (
-                    '\n'.join(installed_files)
-                    )
+
+                installed_part_options[part] = saved_options
+                saved_options['__buildout_installed__'
+                              ] = '\n'.join(installed_files)
+                saved_options['__buildout_signature__'] = signature
+
                 if part not in installed_parts:
                     installed_parts.append(part)
+
         finally:
             installed_part_options['buildout']['parts'] = ' '.join(
                 [p for p in conf_parts if p in installed_parts]
@@ -475,7 +522,9 @@ class Buildout(dict):
         return self._buildout_path(self['buildout']['installed'])
 
     def _uninstall(self, installed):
-        for f in installed.split():
+        for f in installed.split('\n'):
+            if not f:
+                continue
             f = self._buildout_path(f)
             if os.path.isdir(f):
                 shutil.rmtree(f)

src/zc/buildout/tests.py

@@ -178,6 +178,8 @@ def test_comparing_saved_options_with_funny_characters():
     ...     def install(self):
     ...         open('t', 'w').write('t')
     ...         return 't'
+    ...
+    ...     update = install
     ... ''')
 
 
@@ -214,7 +216,7 @@ uninstalling anything because the configuration hasn't changed.
 
     >>> print system(buildout), # doctest: +ELLIPSIS
     buildout: Develop: ...setup.py
-    buildout: Installing debug
+    buildout: Updating debug
 """
 
 
@@ -277,22 +279,22 @@ Options:
 <BLANKLINE>
   -q
 <BLANKLINE>
-     Deccreaae the level of verbosity.  This option can be used multiple times.
+     Decrease the level of verbosity.  This option can be used multiple times.
 <BLANKLINE>
   -c config_file
 <BLANKLINE>
      Specify the path to the buildout configuration file to be used.
-     This defaults to the file named"buildout.cfg" in the current
-     working directory. 
+     This defaults to the file named "buildout.cfg" in the current
+     working directory.
 <BLANKLINE>
 Assignments are of the form: section:option=value and are used to
-provide configuration options that override those givem in the
+provide configuration options that override those given in the
 configuration file.  For example, to run the buildout in offline mode,
 use buildout:offline=true.
 <BLANKLINE>
 Options and assignments can be interspersed.
 <BLANKLINE>
-Commmonds:
+Commands:
 <BLANKLINE>
   install [parts]
 <BLANKLINE>
@@ -324,22 +326,22 @@ Options:
 <BLANKLINE>
   -q
 <BLANKLINE>
-     Deccreaae the level of verbosity.  This option can be used multiple times.
+     Decrease the level of verbosity.  This option can be used multiple times.
 <BLANKLINE>
   -c config_file
 <BLANKLINE>
      Specify the path to the buildout configuration file to be used.
-     This defaults to the file named"buildout.cfg" in the current
-     working directory. 
+     This defaults to the file named "buildout.cfg" in the current
+     working directory.
 <BLANKLINE>
 Assignments are of the form: section:option=value and are used to
-provide configuration options that override those givem in the
+provide configuration options that override those given in the
 configuration file.  For example, to run the buildout in offline mode,
 use buildout:offline=true.
 <BLANKLINE>
 Options and assignments can be interspersed.
 <BLANKLINE>
-Commmonds:
+Commands:
 <BLANKLINE>
   install [parts]
 <BLANKLINE>

src/zc/buildout/update.txt

@@ -44,6 +44,7 @@ zc.buildout used:
     ...         for project in 'zc.buildout', 'setuptools':
     ...             req = pkg_resources.Requirement.parse(project)
     ...             print project, pkg_resources.working_set.find(req).version
+    ...         return ()
     ... """)
 
 

zc.recipe.egg_/CHANGES.txt

@@ -8,6 +8,8 @@ To do
 Change History
 **************
 
+Updated to work with zc.buildout 1.0.0b10.
+
 1.0.0b1
 =======
 

zc.recipe.egg_/src/zc/recipe/egg/api.txt

@@ -38,6 +38,9 @@ around the egg recipe:
     ...         for d in ws:
     ...             print d
     ...         print 'extra paths:', self.egg.extra_paths
+    ...         return ()
+    ...
+    ...     update = install
     ... """)
 
 Here we instantiated the egg recipe in the constructor, saving it in

zc.recipe.egg_/src/zc/recipe/egg/custom.py

@@ -67,7 +67,7 @@ class Custom:
 
     def install(self):
         if self.buildout['buildout'].get('offline') == 'true':
-            return
+            return ()
         options = self.options
         distribution = options.get('eggs', self.name).strip()
         build_ext = dict([
@@ -80,3 +80,6 @@ class Custom:
             self.links, self.index, options['executable'], [options['_e']],
             )
         
+        return ()
+
+    update = install

zc.recipe.egg_/src/zc/recipe/egg/egg.py

@@ -119,3 +119,6 @@ class Egg:
                 interpreter=options.get('interpreter'),
                 )
 
+        return ()
+
+    update = install

zc.recipe.testrunner/CHANGES.txt

@@ -2,6 +2,8 @@
 Change History
 **************
 
+Updated to work with zc.buildout 1.0.0b10.
+
 1.0.0b2
 =======
 

zc.recipe.testrunner/src/zc/recipe/testrunner/__init__.py

@@ -54,6 +54,8 @@ class TestRunner:
                 )),
             )
 
+    update = install
+
 arg_template = """[
   '--test-path', %(TESTPATH)s,
   ]"""