matplotlib · tacaswell · Aug 24, 2019 · Aug 19, 2019 · Aug 24, 2019 · anntzer
diff --git a/doc/api/next_api_changes/2019-08-19-pass_gid.rst b/doc/api/next_api_changes/2019-08-19-pass_gid.rst
@@ -0,0 +1,10 @@
+The ``gid`` is now correctly passed to svg output
+`````````````````````````````````````````````````
+
+Previously, if a figure, axis, legend or some other artists had a custom
+``gid`` set (e.g. via ``.set_gid()``), this would not be reflected in
+the svg output. Instead a default gid, like ``figure_1`` would be shown.
+This is now fixed, such that e.g. ``fig.set_gid("myfigure")`` correctly
+shows up as ``<g id="myfigure">`` in the svg file. If you relied on the
+gid having the default format, you now need to make sure not to set the
+``gid`` parameter of the artists.
diff --git a/lib/matplotlib/axes/_base.py b/lib/matplotlib/axes/_base.py
@@ -2560,7 +2560,7 @@ def draw(self, renderer=None, inframe=False):
             return
         self._unstale_viewLim()
 
-        renderer.open_group('axes')
+        renderer.open_group('axes', gid=self.get_gid())
 
         # prevent triggering call backs during the draw process
         self._stale = True

diff --git a/lib/matplotlib/axis.py b/lib/matplotlib/axis.py
@@ -291,7 +291,7 @@ def draw(self, renderer):
         if not self.get_visible():
             self.stale = False
             return
-        renderer.open_group(self.__name__)
+        renderer.open_group(self.__name__, gid=self.get_gid())
         for artist in [self.gridline, self.tick1line, self.tick2line,
                        self.label1, self.label2]:
             artist.draw(renderer)
@@ -1222,7 +1222,7 @@ def draw(self, renderer, *args, **kwargs):
 
         if not self.get_visible():
             return
-        renderer.open_group(__name__)
+        renderer.open_group(__name__, gid=self.get_gid())
 
         ticks_to_draw = self._update_ticks()
         ticklabelBoxes, ticklabelBoxes2 = self._get_tick_bboxes(ticks_to_draw,

diff --git a/lib/matplotlib/collections.py b/lib/matplotlib/collections.py
@@ -1882,7 +1882,7 @@ def convert_mesh_to_paths(tri):
     def draw(self, renderer):
         if not self.get_visible():
             return
-        renderer.open_group(self.__class__.__name__)
+        renderer.open_group(self.__class__.__name__, gid=self.get_gid())
         transform = self.get_transform()
 
         # Get a list of triangles and the color at each vertex.

diff --git a/lib/matplotlib/figure.py b/lib/matplotlib/figure.py
@@ -1724,7 +1724,7 @@ def draw(self, renderer):
                         child.apply_aspect()
 
         try:
-            renderer.open_group('figure')
+            renderer.open_group('figure', gid=self.get_gid())
             if self.get_constrained_layout() and self.axes:
                 self.execute_constrained_layout(renderer)
             if self.get_tight_layout() and self.axes:

diff --git a/lib/matplotlib/legend.py b/lib/matplotlib/legend.py
@@ -633,7 +633,7 @@ def draw(self, renderer):
         if not self.get_visible():
             return
 
-        renderer.open_group('legend')
+        renderer.open_group('legend', gid=self.get_gid())
 
         fontsize = renderer.points_to_pixels(self._fontsize)
 

diff --git a/lib/matplotlib/table.py b/lib/matplotlib/table.py
@@ -411,7 +411,7 @@ def draw(self, renderer):
 
         if not self.get_visible():
             return
-        renderer.open_group('table')
+        renderer.open_group('table', gid=self.get_gid())
         self._update_positions(renderer)
 
         for key in sorted(self._cells):

diff --git a/lib/matplotlib/tests/test_backend_svg.py b/lib/matplotlib/tests/test_backend_svg.py
@@ -1,6 +1,5 @@
 import numpy as np
 from io import BytesIO
-import os
 import re
 import tempfile
 import warnings
@@ -145,3 +144,67 @@ def test_svgnone_with_data_coordinates():
         buf = fd.read().decode()
 
     assert expected in buf
+
+
+def test_gid():
+    """Test that object gid appears in output svg."""
+    from matplotlib.offsetbox import OffsetBox
+    from matplotlib.axis import Tick
+
+    fig = plt.figure()
+
+    ax1 = fig.add_subplot(131)
+    ax1.imshow([[1., 2.], [2., 3.]], aspect="auto")
+    ax1.scatter([1, 2, 3], [1, 2, 3], label="myscatter")
+    ax1.plot([2, 3, 1], label="myplot")
+    ax1.legend()
+    ax1a = ax1.twinx()
+    ax1a.bar([1, 2, 3], [1, 2, 3])
+
+    ax2 = fig.add_subplot(132, projection="polar")
+    ax2.plot([0, 1.5, 3], [1, 2, 3])
+
+    ax3 = fig.add_subplot(133, projection="3d")
+    ax3.plot([1, 2], [1, 2], [1, 2])
+
+    fig.canvas.draw()
+
+    gdic = {}
+    for idx, obj in enumerate(fig.findobj(include_self=True)):
+        if obj.get_visible():
+            gid = f"test123{obj.__class__.__name__}_{idx}"
+            gdic[gid] = obj
+            obj.set_gid(gid)
+
+    fd = BytesIO()
+    fig.savefig(fd, format='svg')
+    fd.seek(0)
+    buf = fd.read().decode()
+    fd.close()
+
+    def include(gid, obj):
+        # we need to exclude certain objects which will not appear in the svg
+        if isinstance(obj, OffsetBox):
+            return False
+        if isinstance(obj, plt.Text):
+            if obj.get_text() == "":
+                return False
+            elif obj.axes is None:
+                return False
+        if isinstance(obj, plt.Line2D):
+            if np.array(obj.get_data()).shape == (2, 1):
+                return False
+            elif not hasattr(obj, "axes") or obj.axes is None:
+                return False
+        if isinstance(obj, Tick):
+            loc = obj.get_loc()
+            if loc == 0:
+                return False
+            vi = obj.get_view_interval()
+            if loc < min(vi) or loc > max(vi):
+                return False
+        return True
+
+    for gid, obj in gdic.items():
+        if include(gid, obj):
+            assert gid in buf
diff --git a/lib/mpl_toolkits/axisartist/axis_artist.py b/lib/mpl_toolkits/axisartist/axis_artist.py
@@ -127,7 +127,7 @@ def draw(self, renderer):
 
         if not self._visible:
             return
-        renderer.open_group('line2d')
+        renderer.open_group('line2d', gid=self.get_gid())
 
         gc = renderer.new_gc()
         self._set_gc_clip(gc)
@@ -1230,7 +1230,7 @@ def draw(self, renderer):
         if not self.get_visible():
             return
 
-        renderer.open_group(__name__)
+        renderer.open_group(__name__, gid=self.get_gid())
 
         self._axis_artist_helper.update_lim(self.axes)
 

diff --git a/lib/mpl_toolkits/mplot3d/axis3d.py b/lib/mpl_toolkits/mplot3d/axis3d.py
@@ -190,7 +190,7 @@ def _get_coord_info(self, renderer):
         return mins, maxs, centers, deltas, tc, highs
 
     def draw_pane(self, renderer):
-        renderer.open_group('pane3d')
+        renderer.open_group('pane3d', gid=self.get_gid())
 
         mins, maxs, centers, deltas, tc, highs = self._get_coord_info(renderer)
 
@@ -209,7 +209,7 @@ def draw_pane(self, renderer):
     @artist.allow_rasterization
     def draw(self, renderer):
         self.label._transform = self.axes.transData
-        renderer.open_group('axis3d')
+        renderer.open_group('axis3d', gid=self.get_gid())
 
         ticks = self._update_ticks()