Fixed layer ID determination to use only the first group of contiguou…

…s digit (#606)

CHANGELOG.md

@@ -11,7 +11,7 @@ Release date: UNRELEASED
 
 ### Bug fixes
 
-* ...
+* Fixed a design issue with the `read` command where disjoints groups of digit in layer names would be used to determine layer IDs. Only the first contiguous group of digit is used, so a layer named "01-layer1" would now have layer ID of 1 instead of 11 (#606)
 
 ### API changes
 

tests/test_files.py

@@ -614,3 +614,39 @@ def test_read_svg_by_attributes_default_page_size(
     )
 
     assert doc.page_size == pytest.approx(target)
+
+
+def test_read_layer_id_extraction():
+    from vpype.io import _extract_digit_group
+
+    assert _extract_digit_group("") is None
+    assert _extract_digit_group("layer") is None
+    assert _extract_digit_group("11layer") == "11"
+    assert _extract_digit_group("11layer332") == "11"
+    assert _extract_digit_group("lay11er332") == "11"
+    assert _extract_digit_group("layer332") == "332"
+
+
+@pytest.mark.parametrize(
+    ("attr", "exp"),
+    [
+        ("", 1),
+        ('id="5"', 5),
+        ('id="56adf5"', 56),
+        ('id="asdf53adf5"', 53),
+        ('inkscape:label="5" id="6"', 5),
+        ('inkscape:label="hello" id="world6"', 6),
+        ('inkscape:label="47hello25" id="world6"', 47),
+    ],
+)
+def test_read_layer_id_from_svg(attr, exp):
+    svg = f"""<?xml version="1.0"?><svg width="500" height="300" 
+    xmlns:inkscape="http://www.inkscape.org/namespaces/inkscape">
+        <g {attr}>
+                <line x1="0" y1="0" x2="10" y2="10" fill="red" />
+        </g>
+    </svg>"""
+
+    doc = vp.read_multilayer_svg(io.StringIO(svg), 0.1)
+    assert doc.layers.keys() == {exp}
+    assert len(doc.layers[exp]) == 1

vpype/io.py

@@ -165,7 +165,7 @@ def _merge_metadata(
 
 
 def _element_to_paths(elem: svgelements.SVGElement) -> _PathType | None:
-    """Convert a SVG element into a path object that can be processed by
+    """Convert an SVG element into a path object that can be processed by
     :func:`_flattened_paths_to_line_collection`
 
     Args:
@@ -382,7 +382,7 @@ def read_svg(
     default_width: float | None = None,
     default_height: float | None = None,
 ) -> tuple[LineCollection, float, float]:
-    """Read a SVG file an return its content as a :class:`LineCollection` instance.
+    """Read an SVG file and return its content as a :class:`LineCollection` instance.
 
     All curved geometries are chopped in segments no longer than the value of *quantization*.
     Optionally, the geometries are simplified using Shapely, using the value of *quantization*
@@ -425,6 +425,21 @@ def read_svg(
     return lc, svg.width, svg.height
 
 
+_LID_RE = re.compile(r"\d+")
+
+
+def _extract_digit_group(label: str) -> str | None:
+    """Extract a layer ID from a label.
+
+    The first continuous group of digit, if any, is returned.
+    """
+    match = _LID_RE.search(label)
+    if match is not None:
+        return match.group()
+    else:
+        return None
+
+
 def read_multilayer_svg(
     file: str | TextIO,
     quantization: float,
@@ -441,9 +456,9 @@ def read_multilayer_svg(
     in layer 1.
 
     Groups are matched to layer ID according their `inkscape:label` attribute, their `id`
-    attribute or their appearing order, in that order of priority. Labels are stripped of
-    non-numeric characters and the remaining is used as layer ID. Lacking numeric characters,
-    the appearing order is used. If the label is 0, its changed to 1.
+    attribute or their appearing order, in that order of priority. The first contiguous group
+    of digits in the label is used as layer ID. Lacking numeric characters, the appearing order
+    is used. If the label is 0, it is changed to 1.
 
     All curved geometries are chopped in segments no longer than the value of *quantization*.
     Optionally, the geometries are simplified using Shapely, using the value of *quantization*
@@ -467,8 +482,8 @@ def read_multilayer_svg(
             provided
 
     Returns:
-         :class:`Document` instance with the imported geometries and its page size set the the
-         SVG dimensions
+         :class:`Document` instance with the imported geometries and its page size set the SVG
+         dimensions
     """
 
     svg = svgelements.SVG.parse(file, width=default_width, height=default_height)
@@ -491,9 +506,9 @@ def _find_groups(group: svgelements.Group) -> Iterator[svgelements.Group]:
         layer_name = g.values.get("{http://www.inkscape.org/namespaces/inkscape}label", None)
 
         # compute a decent layer ID
-        lid_str = re.sub("[^0-9]", "", layer_name or "")
+        lid_str = _extract_digit_group(layer_name or "")
         if not lid_str:
-            lid_str = re.sub("[^0-9]", "", g.values.get("id") or "")
+            lid_str = _extract_digit_group(g.values.get("id") or "")
         if lid_str:
             lid = int(lid_str)
             if lid == 0:
@@ -545,7 +560,7 @@ def read_svg_by_attributes(
     default_width: float | None = None,
     default_height: float | None = None,
 ) -> Document:
-    """Read a SVG file by sorting geometries by unique combination of provided attributes.
+    """Read an SVG file by sorting geometries by unique combination of provided attributes.
 
     All curved geometries are chopped in segments no longer than the value of *quantization*.
     Optionally, the geometries are simplified using Shapely, using the value of *quantization*
@@ -570,8 +585,8 @@ def read_svg_by_attributes(
             provided
 
     Returns:
-         :class:`Document` instance with the imported geometries and its page size set the the
-         SVG dimensions
+         :class:`Document` instance with the imported geometries and its page size set the SVG
+         dimensions
     """
 
     svg = svgelements.SVG.parse(file, width=default_width, height=default_height)
@@ -637,10 +652,10 @@ def write_svg(
     use_svg_metadata: bool = False,
     set_date: bool = True,
 ) -> None:
-    """Create a SVG from a :py:class:`Document` instance.
+    """Create an SVG from a :py:class:`Document` instance.
 
     If no page size is provided (or (0, 0) is passed), the SVG generated has bounds tightly
-    fitted around the geometries. Otherwise the provided size (in pixel) is used. The width
+    fitted around the geometries. Otherwise, the provided size (in pixel) is used. The width
     and height is capped to a minimum of 1 pixel.
 
     By default, no translation is applied on the geometry. If `center=True`, geometries are
@@ -776,7 +791,7 @@ def write_svg(
             color = Color(layer.property(METADATA_FIELD_COLOR))
 
             # we want to avoid a subsequent layer whose color is undefined to have its color
-            # affected by whether or not previous layer have their color defined
+            # affected by whether previous layer have their color defined
             color_idx += 1
 
         group.attribs["stroke"] = color.as_rgb_hex()
@@ -841,7 +856,7 @@ def write_hpgl(
     absolute: bool = False,
     quiet: bool = False,
 ) -> None:
-    """Create a HPGL file from the :class:`Document` instance.
+    """Create an HPGL file from the :class:`Document` instance.
 
     The ``device``/``page_size`` combination must be defined in the built-in or user-provided
     config files or an exception will be raised.
@@ -857,7 +872,7 @@ def write_hpgl(
         page_size: page size string (it must be configured for the selected device)
         landscape: if True, the geometries are generated in landscape orientation
         center: center geometries on page before export
-        device: name of the device to use (the corresponding config must exists). If not
+        device: name of the device to use (the corresponding config must exist). If not
             provided, a default device must be configured, which will be used.
         velocity: if provided, a VS command will be generated with the corresponding value
         absolute: if True, only use absolute coordinates
@@ -879,7 +894,7 @@ def write_hpgl(
 
     # Handle flex paper size.
     # If paper_size is not provided by the config, the paper size is then assumed to be the
-    # same a the current page size. In this case, the config should provide paper_orientation
+    # same as the current page size. In this case, the config should provide paper_orientation
     # since it may not be the same as the document's page size
     paper_size = paper_config.paper_size
     if paper_size is None:

vpype_cli/read.py

@@ -91,9 +91,9 @@ def read(
     display_size: tuple[float, float] | None,
     display_landscape: bool,
 ) -> vp.Document:
-    """Extract geometries from a SVG file.
+    """Extract geometries from an SVG file.
 
-    FILE may be a file path path or a dash (-) to read from the standard input instead.
+    FILE may be a file path or a dash (-) to read from the standard input instead.
 
     By default, the `read` command attempts to preserve the layer structure of the SVG. In this
     context, top-level groups (<g>) are each considered a layer. If any, all non-group,
@@ -102,9 +102,9 @@ def read(
     The following logic is used to determine in which layer each SVG top-level group is
     imported:
 
-        - If a `inkscape:label` attribute is present and contains digit characters, it is \
-stripped of non-digit characters the resulting number is used as target layer. If the \
-resulting number is 0, layer 1 is used instead.
+        - If a `inkscape:label` attribute is present and contains digit characters, the first \
+group of contiguous digits is used as target layer. If the resulting number is 0, layer 1 is \
+used instead.
 
         - If the previous step fails, the same logic is applied to the `id` attribute.
 
@@ -141,7 +141,7 @@ def read(
     length attributes. The crop operation can be disabled with the `--no-crop` option.
 
     In general, SVG boundaries are determined by the `width` and `height` of the top-level
-    <svg> tag. However, the some SVG may have their width and/or height specified as percent
+    <svg> tag. However, some SVGs may have their width and/or height specified as percent
     value or even miss them altogether (in which case they are assumed to be set to 100%). In
     these cases, vpype attempts to use the `viewBox` attribute to determine the page size, or
     revert to a 1000x1000px default. The options `--display-size FORMAT` and