MusicXML: Add support for compressed MusicXML files (command-line option -z)

MusicXML also defined a compressed format, where the .xml file is
stored inside a ZIP archive (with extension .mxl) . In this case, we need to
read the META-INF/container.xml file from the archive to get the name
of the XML file inside the archive, and then load this file. Thanks
to the zipfile module and the StringIO module, implementing this was quite easy.

I also fixed some other small bugs that led to crashes.

diff --git a/input/regression/musicxml/20a-Compressed-MusicXML-Sample.mxl b/input/regression/musicxml/20a-Compressed-MusicXML-Sample.mxl
new file mode 100644 (file)
index 0000000..0d41bf3
Binary files /dev/null and b/input/regression/musicxml/20a-Compressed-MusicXML-Sample.mxl differ

diff --git a/scripts/musicxml2ly.py b/scripts/musicxml2ly.py
index e04578aecd1de62227aa71ef5dfcdf60b6149a5d..8f3b42a3967aaf8cc376f6e95b2ae5468e30e1f8 100644 (file)
--- a/scripts/musicxml2ly.py
+++ b/scripts/musicxml2ly.py
@@ -6,6 +6,8 @@ import re
 import os
 import string
 import codecs
+import zipfile
+import StringIO
 from gettext import gettext as _
 
 """
@@ -117,13 +119,13 @@ def extract_layout_information (tree):
             #    light barline, octave shift, pedal, slur middle, slur tip,
             #    staff, stem, tie middle, tie tip, tuplet bracket, and wedge
             tp = lw.type
-            w = from_tenths (lw.get_data ())
+            w = from_tenths (lw.get_text  ())
             # TODO: Do something with these values!
         nss = appearance.get_named_children ('note-size')
         for ns in nss:
             # Possible types are: cue, grace and large
             tp = ns.type
-            sz = from_tenths (ns.get_data ())
+            sz = from_tenths (ns.get_text ())
             # TODO: Do something with these values!
         # <other-appearance> elements have no specified meaning
 
@@ -1624,6 +1626,12 @@ Copyright (c) 2005--2007 by
                   dest="use_lxml",
                   help=_ ("Use lxml.etree; uses less memory and cpu time."))
 
+    p.add_option ('-z', '--compressed',
+                  action = "store_true",
+                  dest = 'compressed',
+                  default = False,
+                  help = _ ("Input file is a zip-compressed MusicXML file."))
+
     p.add_option ('-l', '--language',
                   action = "store",
                   help = _ ("Use a different language file, e.g. 'deutsch' for deutsch.ly."))
@@ -1734,28 +1742,54 @@ def print_ly_additional_definitions (printer, filename):
         printer.print_verbatim (additional_definitions.get (a, ''))
     printer.newline ()
 
-
-def read_musicxml (filename, use_lxml):
+# Read in the tree from the given I/O object (either file or string) and 
+# demarshall it using the classes from the musicxml.py file
+def read_xml (io_object, use_lxml):
     if use_lxml:
         import lxml.etree
-        
-        tree = lxml.etree.parse (filename)
+        tree = lxml.etree.parse (io_object)
         mxl_tree = musicxml.lxml_demarshal_node (tree.getroot ())
         return mxl_tree
     else:
         from xml.dom import minidom, Node
-        
-        doc = minidom.parse(filename)
+        doc = minidom.parse(io_object)
         node = doc.documentElement
         return musicxml.minidom_demarshal_node (node)
-
     return None
 
 
+def read_musicxml (filename, compressed, use_lxml):
+    raw_string = None
+    if compressed:
+        progress ("Input file %s is compressed, extracting raw MusicXML data" % filename)
+        z = zipfile.ZipFile (filename, "r")
+        container_xml = z.read ("META-INF/container.xml")
+        if not container_xml:
+            return None
+        container = read_xml (StringIO.StringIO (container_xml), use_lxml)
+        if not container:
+            return None
+        rootfiles = container.get_maybe_exist_named_child ('rootfiles')
+        if not rootfiles:
+            return None
+        rootfile_list = rootfiles.get_named_children ('rootfile')
+        mxml_file = None
+        if len (rootfile_list) > 0:
+            mxml_file = getattr (rootfile_list[0], 'full-path', None)
+        if mxml_file:
+            raw_string = z.read (mxml_file)
+
+    io_object = filename
+    if raw_string:
+        io_object = StringIO.StringIO (raw_string)
+
+    return read_xml (io_object, use_lxml)
+
+
 def convert (filename, options):
     progress ("Reading MusicXML from %s ..." % filename)
     
-    tree = read_musicxml (filename, options.use_lxml)
+    tree = read_musicxml (filename, options.compressed, options.use_lxml)
     parts = tree.get_typed_children (musicxml.Part)
     (voices, staff_info) = get_all_voices (parts)
 
@@ -1808,10 +1842,10 @@ def convert (filename, options):
 def get_existing_filename_with_extension (filename, ext):
     if os.path.exists (filename):
         return filename
-    newfilename = filename + ".xml"
+    newfilename = filename + "." + ext
     if os.path.exists (newfilename):
         return newfilename;
-    newfilename = filename + "xml"
+    newfilename = filename + ext
     if os.path.exists (newfilename):
         return newfilename;
     return ''
@@ -1832,6 +1866,9 @@ def main ():
 
     # Allow the user to leave out the .xml or xml on the filename
     filename = get_existing_filename_with_extension (args[0], "xml")
+    if not filename:
+        filename = get_existing_filename_with_extension (args[0], "mxl")
+        options.compressed = True
     if filename and os.path.exists (filename):
         voices = convert (filename, options)
     else: