Add a ``schema`` command to cmd ctrl to generate schema image.

This changeset add the new commande and do some refactoring in cwconfig and
schema.py to allow the use of CubicWebNoAppConfiguration with
CubicWebSchemaLoader.

devtools/devctl.py

@@ -14,12 +14,16 @@ from os import mkdir, chdir, getcwd
 from os.path import join, exists, abspath, basename, normpath, split, isdir
 from copy import deepcopy
 from warnings import warn
+from tempfile import NamedTemporaryFile
+from subprocess import Popen
 
 from logilab.common import STD_BLACKLIST
 from logilab.common.modutils import get_module_files
 from logilab.common.textutils import splitstrip
 from logilab.common.shellutils import ASK
-from logilab.common.clcommands import register_commands
+from logilab.common.clcommands import register_commands, pop_arg
+
+from yams import schema2dot
 
 from cubicweb.__pkginfo__ import version as cubicwebversion
 from cubicweb import CW_SOFTWARE_ROOT as BASEDIR, BadCommandUsage
@@ -35,15 +39,10 @@ class DevCubeConfiguration(ServerConfiguration, WebConfiguration):
     cubicweb_appobject_path = ServerConfiguration.cubicweb_appobject_path | WebConfiguration.cubicweb_appobject_path
     cube_appobject_path = ServerConfiguration.cube_appobject_path | WebConfiguration.cube_appobject_path
 
-    def __init__(self, cube):
-        super(DevCubeConfiguration, self).__init__(cube)
-        if cube is None:
-            self._cubes = ()
-        else:
-            self._cubes = self.reorder_cubes(self.expand_cubes(self.my_cubes(cube)))
-
-    def my_cubes(self, cube):
-        return (cube,) + self.cube_dependencies(cube) + self.cube_recommends(cube)
+    def __init__(self, *cubes):
+        super(DevCubeConfiguration, self).__init__(cubes[0])
+        self._cubes = self.reorder_cubes(self.expand_cubes(cubes,
+                                         with_recommends=True))
 
     @property
     def apphome(self):
@@ -61,9 +60,6 @@ class DevDepConfiguration(DevCubeConfiguration):
     to filter out message ids from cubicweb and dependencies of a cube
     """
 
-    def my_cubes(self, cube):
-        return self.cube_dependencies(cube) + self.cube_recommends(cube)
-
     def default_log_file(self):
         return None
 
@@ -624,9 +620,42 @@ class ExamineLogCommand(Command):
         for clocktime, cputime, occ, rql in stat:
             print '%.2f;%.2f;%.2f;%s;%s' % (clocktime/total_time, clocktime, cputime, occ, rql)
 
+class GenerateSchema(Command):
+    """Generate schema image for the given cube"""
+    name = "schema"
+    arguments = '<cube>'
+    options = [('output-file', {'type':'file', 'default': None,
+                 'metavar': '<file>', 'short':'o', 'help':'output image file',
+                 'input':False}),
+               ('viewer', {'type': 'string', 'default':None,
+                'short': "w", 'metavar':'<cmd>',
+                 'help':'command use to view the generated file (empty for none)'}
+               ),
+              ]
+
+    def run(self, args):
+        from logilab.common.textutils import splitstrip
+        cubes = splitstrip(pop_arg(args, 1))
+
+        dev_conf = DevCubeConfiguration(*cubes)
+        schema = dev_conf.load_schema()
+
+
+        out, viewer = self['output-file'], self['viewer']
+        if out is None:
+            tmp_file = NamedTemporaryFile(suffix=".svg")
+            out = tmp_file.name
+        schema2dot.schema2dot(schema, out,
+            #skiptypes=("identity",)
+            )
+        if viewer:
+            p = Popen((viewer, out))
+            p.wait()
+
 register_commands((UpdateCubicWebCatalogCommand,
                    UpdateTemplateCatalogCommand,
                    LiveServerCommand,
                    NewCubeCommand,
                    ExamineLogCommand,
+                   GenerateSchema,
                    ))