Include closurebuilder.py from the closure-library.

Add the minimal part of closure-library to pull in
closurebuilder.py.  closurebuilder.py depends on a few other
.js files as well as goog.base.  These are included as well.
The directory tree mimics that of the closure-library to
keep things easy to figure out.

Author: chirayuk

lib/closure-library/closure/bin/build/closurebuilder.py

@@ -0,0 +1,256 @@
+#!/usr/bin/env python
+#
+# Copyright 2009 The Closure Library Authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS-IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Utility for Closure Library dependency calculation.
+
+ClosureBuilder scans source files to build dependency info.  From the
+dependencies, the script can produce a manifest in dependency order,
+a concatenated script, or compiled output from the Closure Compiler.
+
+Paths to files can be expressed as individual arguments to the tool (intended
+for use with find and xargs).  As a convenience, --root can be used to specify
+all JS files below a directory.
+
+usage: %prog [options] [file1.js file2.js ...]
+"""
+
+__author__ = '[email protected] (Nathan Naze)'
+
+
+import logging
+import optparse
+import os
+import sys
+
+import depstree
+import jscompiler
+import source
+import treescan
+
+
+def _GetOptionsParser():
+  """Get the options parser."""
+
+  parser = optparse.OptionParser(__doc__)
+  parser.add_option('-i',
+                    '--input',
+                    dest='inputs',
+                    action='append',
+                    default=[],
+                    help='One or more input files to calculate dependencies '
+                    'for.  The namespaces in this file will be combined with '
+                    'those given with the -n flag to form the set of '
+                    'namespaces to find dependencies for.')
+  parser.add_option('-n',
+                    '--namespace',
+                    dest='namespaces',
+                    action='append',
+                    default=[],
+                    help='One or more namespaces to calculate dependencies '
+                    'for.  These namespaces will be combined with those given '
+                    'with the -i flag to form the set of namespaces to find '
+                    'dependencies for.  A Closure namespace is a '
+                    'dot-delimited path expression declared with a call to '
+                    'goog.provide() (e.g. "goog.array" or "foo.bar").')
+  parser.add_option('--root',
+                    dest='roots',
+                    action='append',
+                    default=[],
+                    help='The paths that should be traversed to build the '
+                    'dependencies.')
+  parser.add_option('-o',
+                    '--output_mode',
+                    dest='output_mode',
+                    type='choice',
+                    action='store',
+                    choices=['list', 'script', 'compiled'],
+                    default='list',
+                    help='The type of output to generate from this script. '
+                    'Options are "list" for a list of filenames, "script" '
+                    'for a single script containing the contents of all the '
+                    'files, or "compiled" to produce compiled output with '
+                    'the Closure Compiler.  Default is "list".')
+  parser.add_option('-c',
+                    '--compiler_jar',
+                    dest='compiler_jar',
+                    action='store',
+                    help='The location of the Closure compiler .jar file.')
+  parser.add_option('-f',
+                    '--compiler_flags',
+                    dest='compiler_flags',
+                    default=[],
+                    action='append',
+                    help='Additional flags to pass to the Closure compiler. '
+                    'To pass multiple flags, --compiler_flags has to be '
+                    'specified multiple times.')
+  parser.add_option('--output_file',
+                    dest='output_file',
+                    action='store',
+                    help=('If specified, write output to this path instead of '
+                          'writing to standard output.'))
+
+  return parser
+
+
+def _GetInputByPath(path, sources):
+  """Get the source identified by a path.
+
+  Args:
+    path: str, A path to a file that identifies a source.
+    sources: An iterable collection of source objects.
+
+  Returns:
+    The source from sources identified by path, if found.  Converts to
+    absolute paths for comparison.
+  """
+  for js_source in sources:
+    # Convert both to absolute paths for comparison.
+    if os.path.abspath(path) == os.path.abspath(js_source.GetPath()):
+      return js_source
+
+
+def _GetClosureBaseFile(sources):
+  """Given a set of sources, returns the one base.js file.
+
+  Note that if zero or two or more base.js files are found, an error message
+  will be written and the program will be exited.
+
+  Args:
+    sources: An iterable of _PathSource objects.
+
+  Returns:
+    The _PathSource representing the base Closure file.
+  """
+  base_files = [
+      js_source for js_source in sources if _IsClosureBaseFile(js_source)]
+
+  if not base_files:
+    logging.error('No Closure base.js file found.')
+    sys.exit(1)
+  if len(base_files) > 1:
+    logging.error('More than one Closure base.js files found at these paths:')
+    for base_file in base_files:
+      logging.error(base_file.GetPath())
+    sys.exit(1)
+  return base_files[0]
+
+
+def _IsClosureBaseFile(js_source):
+  """Returns true if the given _PathSource is the Closure base.js source."""
+  return (os.path.basename(js_source.GetPath()) == 'base.js' and
+          js_source.provides == set(['goog']))
+
+
+class _PathSource(source.Source):
+  """Source file subclass that remembers its file path."""
+
+  def __init__(self, path):
+    """Initialize a source.
+
+    Args:
+      path: str, Path to a JavaScript file.  The source string will be read
+        from this file.
+    """
+    super(_PathSource, self).__init__(source.GetFileContents(path))
+
+    self._path = path
+
+  def GetPath(self):
+    """Returns the path."""
+    return self._path
+
+
+def main():
+  logging.basicConfig(format=(sys.argv[0] + ': %(message)s'),
+                      level=logging.INFO)
+  options, args = _GetOptionsParser().parse_args()
+
+  # Make our output pipe.
+  if options.output_file:
+    out = open(options.output_file, 'w')
+  else:
+    out = sys.stdout
+
+  sources = set()
+
+  logging.info('Scanning paths...')
+  for path in options.roots:
+    for js_path in treescan.ScanTreeForJsFiles(path):
+      sources.add(_PathSource(js_path))
+
+  # Add scripts specified on the command line.
+  for js_path in args:
+    sources.add(_PathSource(js_path))
+
+  logging.info('%s sources scanned.', len(sources))
+
+  # Though deps output doesn't need to query the tree, we still build it
+  # to validate dependencies.
+  logging.info('Building dependency tree..')
+  tree = depstree.DepsTree(sources)
+
+  input_namespaces = set()
+  inputs = options.inputs or []
+  for input_path in inputs:
+    js_input = _GetInputByPath(input_path, sources)
+    if not js_input:
+      logging.error('No source matched input %s', input_path)
+      sys.exit(1)
+    input_namespaces.update(js_input.provides)
+
+  input_namespaces.update(options.namespaces)
+
+  if not input_namespaces:
+    logging.error('No namespaces found. At least one namespace must be '
+                  'specified with the --namespace or --input flags.')
+    sys.exit(2)
+
+  # The Closure Library base file must go first.
+  base = _GetClosureBaseFile(sources)
+  deps = [base] + tree.GetDependencies(input_namespaces)
+
+  output_mode = options.output_mode
+  if output_mode == 'list':
+    out.writelines([js_source.GetPath() + '\n' for js_source in deps])
+  elif output_mode == 'script':
+    out.writelines([js_source.GetSource() for js_source in deps])
+  elif output_mode == 'compiled':
+
+    # Make sure a .jar is specified.
+    if not options.compiler_jar:
+      logging.error('--compiler_jar flag must be specified if --output is '
+                    '"compiled"')
+      sys.exit(2)
+
+    compiled_source = jscompiler.Compile(
+        options.compiler_jar,
+        [js_source.GetPath() for js_source in deps],
+        options.compiler_flags)
+
+    if compiled_source is None:
+      logging.error('JavaScript compilation failed.')
+      sys.exit(1)
+    else:
+      logging.info('JavaScript compilation succeeded.')
+      out.write(compiled_source)
+
+  else:
+    logging.error('Invalid value for --output flag.')
+    sys.exit(2)
+
+
+if __name__ == '__main__':
+  main()