Add temp/ to .gitignore

When resolving a relative image path, first search relative to the main YAML's path, then relative to the prepended YAML if unsuccessful.

.gitignore

@@ -10,4 +10,4 @@ dist
 venv/
 desktop.ini
 thumbs.db
-
+temp/

src/wireviz/DataClasses.py

@@ -32,7 +32,6 @@ OneOrMoreWires = Union[Wire, Tuple[Wire, ...]] # One or a tuple of wires
 
 @dataclass
 class Image:
-    gv_dir: InitVar[Path] # Directory of .gv file injected as context during parsing
     # Attributes of the image object <img>:
     src: str
     scale: Optional[ImageScale] = None
@@ -44,7 +43,7 @@ class Image:
     caption: Optional[MultilineHypertext] = None
     # See also HTML doc at https://graphviz.org/doc/info/shapes.html#html
 
-    def __post_init__(self, gv_dir):
+    def __post_init__(self) -> None:
 
         if self.fixedsize is None:
             # Default True if any dimension specified unless self.scale also is specified.
@@ -60,10 +59,10 @@ class Image:
             # because Graphviz requires both when fixedsize=True.
             if self.height:
                 if not self.width:
-                    self.width = self.height * aspect_ratio(gv_dir.joinpath(self.src))
+                    self.width = self.height * aspect_ratio(self.src)
             else:
                 if self.width:
-                    self.height = self.width / aspect_ratio(gv_dir.joinpath(self.src))
+                    self.height = self.width / aspect_ratio(self.src)
 
 
 @dataclass

src/wireviz/Harness.py

@@ -18,6 +18,7 @@ from wireviz.wv_bom import manufacturer_info_field, component_table_entry, \
 from wireviz.wv_html import generate_html_output
 from wireviz.wv_helper import awg_equiv, mm2_equiv, tuplelist2tsv, flatten2d, \
     open_file_read, open_file_write
+from wireviz.svgembed import embed_svg_images, embed_svg_images_file
 
 
 class Harness:
@@ -341,13 +342,9 @@ class Harness:
         return data.read()
 
     @property
-    def svg(self):
+    def svg(self) -> str:
-        from io import BytesIO
         graph = self.create_graph()
-        data = BytesIO()
+        return embed_svg_images(graph.pipe(format='svg').decode('utf-8'), Path.cwd())
-        data.write(graph.pipe(format='svg'))
-        data.seek(0)
-        return data.read()
 
     def output(self, filename: (str, Path), view: bool = False, cleanup: bool = True, fmt: tuple = ('pdf', )) -> None:
         # graphical output
@@ -356,6 +353,8 @@ class Harness:
             graph.format = f
             graph.render(filename=filename, view=view, cleanup=cleanup)
         graph.save(filename=f'{filename}.gv')
+        if 'svg' in fmt:
+            embed_svg_images_file(f'{filename}.svg')
         # bom output
         bomlist = bom_list(self.bom())
         with open_file_write(f'{filename}.bom.tsv') as file:

src/wireviz/svgembed.py

@@ -0,0 +1,44 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+import base64
+from pathlib import Path
+import re
+from typing import Union
+
+mime_subtype_replacements = {'jpg': 'jpeg', 'tif': 'tiff'}
+
+def embed_svg_images(svg_in: str, base_path: Union[str, Path] = Path.cwd()) -> str:
+    images_b64 = {}  # cache of base64-encoded images
+
+    def image_tag(pre: str, url: str, post: str) -> str:
+        return f'<image{pre} xlink:href="{url}"{post}>'
+
+    def replace(match: re.Match) -> str:
+        imgurl = match['URL']
+        if not imgurl in images_b64:  # only encode/cache every unique URL once
+            imgurl_abs = (Path(base_path) / imgurl).resolve()
+            images_b64[imgurl] = base64.b64encode(imgurl_abs.read_bytes()).decode('utf-8')
+        return image_tag(
+            match['PRE'] or '',
+            f'data:image/{get_mime_subtype(imgurl)};base64, {images_b64[imgurl]}',
+            match['POST'] or '')
+
+    pattern = re.compile(
+        image_tag(r'(?P<PRE> [^>]*?)?', r'(?P<URL>[^"]*?)', r'(?P<POST> [^>]*?)?'), re.IGNORECASE)
+    return pattern.sub(replace, svg_in)
+
+
+def get_mime_subtype(filename: Union[str, Path]) -> str:
+    mime_subtype = Path(filename).suffix.lstrip('.').lower()
+    if mime_subtype in mime_subtype_replacements:
+        mime_subtype = mime_subtype_replacements[mime_subtype]
+    return mime_subtype
+
+
+def embed_svg_images_file(filename_in: Union[str, Path], overwrite: bool = True) -> None:
+    filename_in = Path(filename_in).resolve()
+    filename_out = filename_in.with_suffix('.b64.svg')
+    filename_out.write_text(embed_svg_images(filename_in.read_text(), filename_in.parent))
+    if overwrite:
+        filename_out.replace(filename_in)

src/wireviz/wireviz.py

@@ -5,7 +5,7 @@ import argparse
 import os
 from pathlib import Path
 import sys
-from typing import Any, Tuple
+from typing import Any, List, Tuple
 
 import yaml
 
@@ -14,15 +14,16 @@ if __name__ == '__main__':
 
 from wireviz import __version__
 from wireviz.Harness import Harness
-from wireviz.wv_helper import expand, open_file_read
+from wireviz.wv_helper import expand, open_file_read, smart_file_resolve
 
 
-def parse(yaml_input: str, file_out: (str, Path) = None, return_types: (None, str, Tuple[str]) = None) -> Any:
+def parse(yaml_input: str, base_path: (str, Path, List) = None, file_out: (str, Path) = None, return_types: (None, str, Tuple[str]) = None) -> Any:
     """
     Parses yaml input string and does the high-level harness conversion
 
     :param yaml_input: a string containing the yaml input data
-    :param file_out:
+    :param base_path: base path used to resolve any relative paths to image files
+    :param file_out: filename of the generated output
     :param return_types: if None, then returns None; if the value is a string, then a
         corresponding data format will be returned; if the value is a tuple of strings,
         then for every valid format in the `return_types` tuple, another return type
@@ -44,10 +45,11 @@ def parse(yaml_input: str, file_out: (str, Path) = None, return_types: (None, st
             if len(yaml_data[sec]) > 0:
                 if ty == dict:
                     for key, attribs in yaml_data[sec].items():
-                        # The Image dataclass might need to open an image file with a relative path.
                         image = attribs.get('image')
                         if isinstance(image, dict):
-                            image['gv_dir'] = Path(file_out if file_out else '').parent # Inject context
+                            image_path = image['src']
+                            if image_path and not Path(image_path).is_absolute():  # resolve relative image path
+                                image['src'] = smart_file_resolve(image_path, base_path)
 
                         if sec == 'connectors':
                             if not attribs.get('autogenerate', False):
@@ -209,7 +211,7 @@ def parse_file(yaml_file: str, file_out: (str, Path) = None) -> None:
         file_out = fn
     file_out = os.path.abspath(file_out)
 
-    parse(yaml_input, file_out=file_out)
+    parse(yaml_input, base_path=Path(yaml_file).parent, file_out=file_out)
 
 
 def parse_cmdline():
@@ -235,6 +237,8 @@ def main():
     with open_file_read(args.input_file) as fh:
         yaml_input = fh.read()
 
+    base_path = [Path(args.input_file).parent]
+
     if args.prepend_file:
         if not os.path.exists(args.prepend_file):
             print(f'Error: prepend input file {args.prepend_file} inaccessible or does not exist, check path')
@@ -242,6 +246,7 @@ def main():
         with open_file_read(args.prepend_file) as fh:
             prepend = fh.read()
             yaml_input = prepend + yaml_input
+        base_path.append(Path(args.prepend_file).parent)
 
     if not args.output_file:
         file_out = args.input_file
@@ -251,7 +256,7 @@ def main():
         file_out = args.output_file
     file_out = os.path.abspath(file_out)
 
-    parse(yaml_input, file_out=file_out)
+    parse(yaml_input, base_path=base_path, file_out=file_out)
 
 
 if __name__ == '__main__':

src/wireviz/wv_helper.py

@@ -1,6 +1,7 @@
 #!/usr/bin/env python3
 # -*- coding: utf-8 -*-
 
+from pathlib import Path
 from typing import List
 import re
 
@@ -117,3 +118,22 @@ def aspect_ratio(image_src):
     except Exception as error:
         print(f'aspect_ratio(): {type(error).__name__}: {error}')
     return 1 # Assume 1:1 when unable to read actual image size
+
+def smart_file_resolve(filename: str, possible_paths: (str, List[str])) -> Path:
+    if not isinstance(possible_paths, List):
+        possible_paths = [possible_paths]
+    filename = Path(filename)
+    if filename.is_absolute():
+        if filename.exists():
+            return filename
+        else:
+            raise Exception(f'{filename} does not exist.')
+    else:  # search all possible paths in decreasing order of precedence
+        possible_paths = [Path(path).resolve() for path in possible_paths if path is not None]
+        for possible_path in possible_paths:
+            resolved_path = (possible_path / filename).resolve()
+            if (resolved_path).exists():
+                return resolved_path
+        else:
+            raise Exception(f'{filename} was not found in any of the following locations: \n' +
+                            '\n'.join([str(x) for x in possible_paths]))