Handle inline svg better

CHANGES

@@ -1,5 +1,10 @@
 
-0.14.3 August xx, 1996
+0.14.3 August ??, 2026
+- handling of inline SVG has been improved.
+    - the inline SVG element is now handled whether or not it has set the svg namespace.
+    - inline SVG is changed to standalone files in EPUB2
+    - inline html5 SVG now adapted for EPUB3, which cares about namespaces
+- an error is no longer emitted when rst output is requested from html input
 - refactored boilerplate stripping for txt files so it only needs to be done once per book. boilerplate is now detected in the text Parser, instead of in the text Writer.
 - `a` tags can't contain block tags in xhtml, so div in `a` and `p` in `a` cause EPUB2 validation errors, so Ebookmaker now changes `p` and `div` occurring in `a` to `span` for EPUB2. I'm not sure why anyone would want to use this markup in a book. Fixes #333
 

src/ebookmaker/HTMLChunker.py

@@ -165,6 +165,9 @@ def shipout_chunk(self, attribs, chunk_id = None, comment = None):
         for e in xpath(self.chunk, '//mathml:math'):
             attribs.rel.add('mathml')
             break
+        for e in xpath(self.chunk, '//xhtml:svg'):
+            attribs.rel.add('svg')
+            break
         for e in xpath(self.chunk, '//svg:svg'):
             attribs.rel.add('svg')
             break

src/ebookmaker/parsers/ImageParser.py

@@ -20,6 +20,7 @@
 from PIL import Image, ImageFile
 from lxml import etree
 
+from libgutenberg.GutenbergGlobals import NS
 from libgutenberg.Logger import debug, critical, error
 from libgutenberg.MediaTypes import mediatypes as mt
 from ebookmaker.parsers import ParserBase
@@ -171,6 +172,7 @@ def serialize(self):
             atts_to_remove = ['data-variant', 'focusable', 'role']
             try:
                 tree = etree.parse(io.BytesIO(self.image_data))
+                svg = tree.getroot()
             except etree.XMLSyntaxError as e:
                 critical(f'SVG image {self.attribs.url} was badly formed XML: {e}')
                 return self.image_data
@@ -181,5 +183,11 @@ def serialize(self):
                 for att in copy.copy(element.attrib):
                     if att.startswith('aria-'):
                         del element.attrib[att]
+                # strip namespaces hanging around, perhaps because it's an extracted image
+                element.tag = etree.QName(element).localname
+            etree.cleanup_namespaces(tree)
+            # restore the root namespace
+            svg.tag = NS.svg.svg
+
             self.image_data = etree.tostring(tree, encoding="utf-8")
         return self.image_data

src/ebookmaker/writers/Epub3Writer.py

@@ -560,6 +560,10 @@ def html_for_epub3(xhtml):
         # add namespace to math elements
         for e in xpath(xhtml, "//xhtml:math"):
             e.attrib['xmlns'] = "http://www.w3.org/1998/Math/MathML"
+        # add namespace to svg
+        for e in xpath(xhtml, "//xhtml:svg"):
+            e.attrib['xmlns'] = "http://www.w3.org/2000/svg"
+
 
     @staticmethod
     def fix_incompatible_css(sheet):

src/ebookmaker/writers/EpubWriter.py

@@ -1125,11 +1125,40 @@ def fix_html5(xhtml):
                 tag.clear()
                 tag.text = text
 
+    @staticmethod
+    def extract_svg(xhtml, parent_url):
+        """
+        convert embedded svg elements to stand-alone svg files that work better n EPUB2.
 
-
-
-
-
+        """
+        svgnum = 0
+        new_parsers = []
+        for svg in xpath(xhtml, '//xhtml:svg'):
+            # make a new parser
+            attribs = parsers.ParserAttributes()
+            svg_parser = parsers.ImageParser.Parser(attribs=attribs)
+            attribs.mediatype = mt.svg
+            attribs.id = f'extracted_svg_{svgnum}'
+            attribs.url = urllib.parse.urljoin(parent_url, f'images/extracted_svg_{svgnum}.svg')
+            svg_parser.image_data = etree.tostring(svg)
+
+            # turn the svg element into an img element
+            for att in svg.attrib:
+                if att not in {"alt", "class", "dir", "height", "id", "ismap", "lang", "longdesc",
+                               "src", "title", "usemap", "width", "xml:lang"}:
+                    del svg.attrib[att]
+            for title in xpath(svg, '//xhtml:title'):
+                svg.attrib['alt'] = title.text_content() or ''
+                break
+            svg.tag = NS.xhtml.img
+            svg.attrib['src'] = attribs.url
+            svg.attrib['id'] = attribs.id
+            for child in list(svg):
+                svg.remove(child)
+
+            # return the new parsers
+            new_parsers.append(svg_parser)
+        return new_parsers
 
     @staticmethod
     def strip_links(xhtml, manifest):
@@ -1352,6 +1381,7 @@ def shipout(self, job, parserlist, ncx):
                     if p.mediatype() == mt.xhtml:
                         opf.spine_item_from_parser(p)
                     else:
+                        debug(f'adding {p.attribs.url} to manifest')
                         opf.manifest_item_from_parser(p)
                 except Exception as what:
                     error("Could not process file %s: %s" % (p.attribs.url, what))
@@ -1457,8 +1487,14 @@ def build(self, job):
                         p.remap_links(idmap)
 
                         xhtml.make_links_absolute(base_url=p.attribs.url)
-                        self.fix_html5(xhtml)
+                        new_parsers = self.extract_svg(xhtml, p.attribs.url)
 
+                        # add the new parsers to parser list so the get handled properly
+                        parserlist.extend(new_parsers)
+                        job.spider.parsers.extend(new_parsers)
+
+                        self.fix_html5(xhtml)
+
                         strip_classes = self.get_classes_with_prop(xhtml)
                         strip_classes = strip_classes.intersection(STRIP_CLASSES)
                         if strip_classes:

src/ebookmaker/writers/RSTWriter.py

@@ -31,6 +31,11 @@ def build (self, job):
         debug ("Creating RST file: %s" % filename)
 
         parser = ParserFactory.ParserFactory.create (job.url)
+
+        has_txt_source = 'text/plain' in str(parser.attribs.orig_mediatype)
+        if not has_txt_source:
+            debug("needs plain text file for conversion: %s from %s", filename, job.url)
+            return
 
         data = parser.preprocess ('utf-8').encode ('utf-8')