# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1543355292 -3600
# Node ID c1284f3e6af52acc94edb87d9f31ebafb8f663f8
# Parent  524700c23195f0e167a24ef0512a2842993f73bd
Made SVG output inline, enabling convenient linking and avoiding attachment use.
Eliminated the redundant identifier parameter for the Graphviz utility class.

diff -r 524700c23195 -r c1284f3e6af5 moinformat/serialisers/html/graphviz.py
--- a/moinformat/serialisers/html/graphviz.py	Tue Nov 27 21:23:24 2018 +0100
+++ b/moinformat/serialisers/html/graphviz.py	Tue Nov 27 22:48:12 2018 +0100
@@ -97,27 +97,36 @@
         format = self.directives.get("format", ["svg"])[0]
         transforms = self.directives.get("transform", [])
 
-        # Graph output is stored for a known page only.
+        inline = format == "svg"
+
+        # Non-inline graph output is stored for a known page only.
 
         pagename = self.metadata.get("pagename")
-        if not pagename:
-            return
+
+        if not inline:
+            if not pagename:
+                return
 
-        # Get an identifier and usable filename to store the output.
+            # Get an identifier and usable filename to store the output.
 
-        identifier = get_output_identifier(text)
-        attachment = "%s.%s" % (identifier, format)
-        filename = self.output.get_attachment_filename(pagename, attachment)
+            identifier = get_output_identifier(text)
+            attachment = "%s.%s" % (identifier, format)
+            filename = self.output.get_attachment_filename(pagename, attachment)
+
+            # Handle situations where no independent output is permitted.
 
-        # Handle situations where no independent output is permitted.
+            if not filename:
+                return
 
-        if not filename:
-            return
+            # Make sure that page attachments can be stored.
 
-        # Make sure that page attachments can be stored.
+            self.output.ensure_attachments(pagename)
+            target, _label = self.linker.translate("attachment:%s" % attachment)
 
-        self.output.ensure_attachments(pagename)
-        target, label = self.linker.translate("attachment:%s" % attachment)
+        # No filename is defined for inline output.
+
+        else:
+            filename = None
 
         # Permit imagemaps only for image formats.
 
@@ -126,7 +135,7 @@
 
         # Configure Graphviz and invoke it.
 
-        graphviz = Graphviz(filter, text, identifier)
+        graphviz = Graphviz(filter, text)
         graphviz.call(format, transforms, filename)
 
         # Obtain any metadata.
@@ -151,8 +160,13 @@
 
         # For other output, create a file and embed the object.
 
+        elif not inline:
+            self.object(target, attributes)
+
+        # Or for inline output, emit it in the document itself.
+
         else:
-            self.object(target, attributes)
+            self.out(graphviz.get_inline_output())
 
 serialiser = HTMLGraphvizSerialiser
 
diff -r 524700c23195 -r c1284f3e6af5 moinformat/utils/graphviz.py
--- a/moinformat/utils/graphviz.py	Tue Nov 27 21:23:24 2018 +0100
+++ b/moinformat/utils/graphviz.py	Tue Nov 27 22:48:12 2018 +0100
@@ -22,6 +22,7 @@
 from os.path import exists, join
 from StringIO import StringIO
 from subprocess import Popen, PIPE
+from xml.sax.saxutils import XMLGenerator
 import gzip
 import sha
 import xml.sax
@@ -63,16 +64,9 @@
     else:
         return s
 
-class MetadataParser(xml.sax.handler.ContentHandler):
-
-    "Parse metadata from the svg element."
+class Parser(xml.sax.handler.ContentHandler):
 
-    def __init__(self):
-        self.attrs = {}
-
-    def startElement(self, name, attrs):
-        if name == self.tagname:
-            self.attrs = dict(attrs)
+    "Common XML parsing functionality."
 
     def parse(self, f):
 
@@ -87,11 +81,9 @@
         finally:
             f.close()
 
-    def get_metadata(self, data, tagname):
+    def parse_data(self, data):
 
-        "Process 'data', returning attributes from 'tagname'."
-
-        self.tagname = tagname
+        "Parse the given 'data'."
 
         f = StringIO(data)
         try:
@@ -99,8 +91,32 @@
         finally:
             f.close()
 
+class MetadataParser(Parser):
+
+    "Parse metadata from the svg element."
+
+    def __init__(self):
+        self.attrs = {}
+
+    def startElement(self, name, attrs):
+        if name == self.tagname:
+            self.attrs = dict(attrs)
+
+    def get_metadata(self, data, tagname):
+
+        "Process 'data', returning attributes from 'tagname'."
+
+        self.tagname = tagname
+        self.parse_data(data)
         return self.attrs
 
+class DocumentSelector(XMLGenerator, Parser):
+
+    "Parse a document and obtain the serialisation of the document node."
+
+    def startDocument(self):
+        pass
+
 def get_output_identifier(text):
 
     "Return an output identifier for the given 'text'."
@@ -179,17 +195,14 @@
 
     "A Graphviz configuration for single or repeated invocation."
 
-    def __init__(self, filter, text, identifier):
+    def __init__(self, filter, text):
 
         """
-        Employ the given 'filter' to produce a graph from the given 'text'. The
-        output 'identifier' for the text is used to provide a filename, if
-        required.
+        Employ the given 'filter' to produce a graph from the given 'text'.
         """
 
         self.filter = filter
         self.text = text
-        self.identifier = identifier
 
     def call(self, format, transforms=None, filename=None):
 
@@ -264,4 +277,20 @@
     def get_output(self):
         return self.output
 
+    def get_inline_output(self):
+
+        """
+        Return a string containing the document element, excluding XML
+        boilerplate.
+        """
+
+        f = StringIO()
+        parser = DocumentSelector(f, "utf-8")
+
+        try:
+            parser.parse_data(self.output)
+            return f.getvalue()
+        finally:
+            f.close()
+
 # vim: tabstop=4 expandtab shiftwidth=4