Issue #3755 Bug Fix for: Shapes and Annotations With yref Parameter Not Drawing on Correct Axis

CHANGELOG.md

@@ -6,8 +6,11 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 
 ### Fixed
   - Fixed another compatibility issue with Pandas 2.0, just affecting `px.*(line_close=True)` [[#4190](https://github.com/plotly/plotly.py/pull/4190)]
-  - Added some rounding to the `make_subplots` function to handle situations where the user-input specs cause the domain to exceed 1 by small amounts [[#4153](https://github.com/plotly/plotly.py/pull/4153)]
+
+  - Added some rounding to the `make_subplots` function to handle situations where the user-input specs cause the domain to exceed 1 by small amounts https://github.com/plotly/plotly.py/pull/4153
   - Sanitize JSON output to prevent an XSS vector when graphs are inserted directly into HTML [[#4196](https://github.com/plotly/plotly.py/pull/4196)]
+  - Fixed issue with shapes and annotations plotting on the wrong y axis when supplied with a specific axis in the `yref` parameter [[#4177](https://github.com/plotly/plotly.py/pull/4177)]
+
 
 ## [5.14.1] - 2023-04-05
 

packages/python/plotly/plotly/basedatatypes.py

@@ -1559,17 +1559,31 @@ def _add_annotation_like(
                         subplot_type=refs[0].subplot_type,
                     )
                 )
-            if len(refs) == 1 and secondary_y:
-                raise ValueError(
-                    """
-Cannot add {prop_singular} to secondary y-axis of subplot at position ({r}, {c})
-because subplot does not have a secondary y-axis"""
-                )
-            if secondary_y:
-                xaxis, yaxis = refs[1].layout_keys
+
+            # If the new_object was created with a yref specified that did not include paper or domain, the specified yref should be used otherwise assign the xref and yref from the layout_keys
+            if (
+                new_obj.yref == None
+                or new_obj.yref == "y"
+                or "paper" in new_obj.yref
+                or "domain" in new_obj.yref
+            ):
+                if len(refs) == 1 and secondary_y:
+                    raise ValueError(
+                        """
+    Cannot add {prop_singular} to secondary y-axis of subplot at position ({r}, {c})
+    because subplot does not have a secondary y-axis""".format(
+                            prop_singular=prop_singular, r=row, c=col
+                        )
+                    )
+                if secondary_y:
+                    xaxis, yaxis = refs[1].layout_keys
+                else:
+                    xaxis, yaxis = refs[0].layout_keys
+                xref, yref = xaxis.replace("axis", ""), yaxis.replace("axis", "")
             else:
-                xaxis, yaxis = refs[0].layout_keys
-            xref, yref = xaxis.replace("axis", ""), yaxis.replace("axis", "")
+                yref = new_obj.yref
+                xaxis = refs[0].layout_keys[0]
+                xref = xaxis.replace("axis", "")
             # if exclude_empty_subplots is True, check to see if subplot is
             # empty and return if it is
             if exclude_empty_subplots and (
@@ -1591,6 +1605,11 @@ def _add_domain(ax_letter, new_axref):
             new_obj.update(xref=xref, yref=yref)
 
         self.layout[prop_plural] += (new_obj,)
+        # The 'new_obj.xref' and 'new_obj.yref' parameters need to be reset otherwise it
+        # will appear as if user supplied yref params when looping through subplots and
+        # will force annotation to be on the axis of the last drawn annotation
+        # i.e. they all end up on the same axis.
+        new_obj.update(xref=None, yref=None)
 
         return self
 
@@ -4034,6 +4053,7 @@ def _process_multiple_axis_spanning_shapes(
                 row=row,
                 col=col,
                 exclude_empty_subplots=exclude_empty_subplots,
+                yref=shape_kwargs["yref"] if "yref" in shape_kwargs.keys() else "y",
             )
         # update xref and yref for the new shapes and annotations
         for layout_obj, n_layout_objs_before in zip(
@@ -4045,10 +4065,13 @@ def _process_multiple_axis_spanning_shapes(
             ):
                 # this was called intending to add to a single plot (and
                 # self.add_{layout_obj} succeeded)
-                # however, in the case of a single plot, xref and yref are not
-                # specified, so we specify them here so the following routines can work
-                # (they need to append " domain" to xref or yref)
-                self.layout[layout_obj][-1].update(xref="x", yref="y")
+                # however, in the case of a single plot, xref and yref MAY not be
+                # specified, IF they are not specified we specify them here so the following routines can work
+                # (they need to append " domain" to xref or yref). If they are specified, we leave them alone.
+                if self.layout[layout_obj][-1].xref is None:
+                    self.layout[layout_obj][-1].update(xref="x")
+                if self.layout[layout_obj][-1].yref is None:
+                    self.layout[layout_obj][-1].update(yref="y")
             new_layout_objs = tuple(
                 filter(
                     lambda x: x is not None,

packages/python/plotly/plotly/tests/test_core/test_update_objects/test_update_annotations.py

@@ -5,6 +5,7 @@
 
 import plotly.graph_objs as go
 from plotly.subplots import make_subplots
+
 import pytest
 
 
@@ -351,6 +352,64 @@ def test_no_exclude_empty_subplots():
         assert fig.layout[k][3]["xref"] == "x4" and fig.layout[k][3]["yref"] == "y4"
 
 
+def test_supplied_yref_on_single_plot_subplot():
+    ### test a (1,1) subplot figure object
+    fig = make_subplots(1, 1)
+    fig.add_trace(go.Scatter(x=[1, 2, 3, 4], y=[1, 2, 2, 1]))
+    fig.add_trace(go.Scatter(x=[1, 2, 3, 4], y=[4, 3, 2, 1], yaxis="y2"))
+    fig.update_layout(
+        yaxis=dict(title="yaxis1 title"),
+        yaxis2=dict(title="yaxis2 title", overlaying="y", side="right"),
+    )
+    # add horizontal line on y2. Secondary_y can be True or False when yref is supplied
+    fig.add_hline(y=3, yref="y2", secondary_y=True)
+    assert fig.layout["shapes"][0]["yref"] == "y2"
+
+
+def test_supplied_yref_on_non_subplot_figure_object():
+    ### test a non-subplot figure object from go.Figure
+    trace1 = go.Scatter(x=[1, 2, 3, 4], y=[1, 2, 2, 1])
+    trace2 = go.Scatter(x=[1, 2, 3, 4], y=[4, 3, 2, 1], yaxis="y2")
+    data = [trace1, trace2]
+    layout = go.Layout(
+        yaxis=dict(title="yaxis1 title"),
+        yaxis2=dict(title="yaxis2 title", overlaying="y", side="right"),
+    )
+    fig = go.Figure(data=data, layout=layout)
+    # add horizontal line on y2. Secondary_y can be True or False when yref is supplied
+    fig.add_hline(y=3, yref="y2", secondary_y=False)
+    assert fig.layout["shapes"][0]["yref"] == "y2"
+
+
+def test_supplied_yref_on_multi_plot_subplot():
+    ### test multiple subploted figure object with subplots.make_subplots
+    fig = make_subplots(
+        rows=1,
+        cols=2,
+        shared_yaxes=False,
+        specs=[[{"secondary_y": True}, {"secondary_y": True}]],
+    )
+    ### Add traces to the first subplot
+    fig.add_trace(go.Scatter(x=[1, 2, 3], y=[1, 2, 3]), row=1, col=1)
+    fig.add_trace(
+        go.Scatter(x=[1, 2, 3], y=[3, 2, 1], yaxis="y2"), row=1, col=1, secondary_y=True
+    )
+    ### Add traces to the second subplot
+    fig.add_trace(go.Scatter(x=[1, 2, 3], y=[1, 2, 3], yaxis="y"), row=1, col=2)
+    fig.add_trace(
+        go.Scatter(x=[1, 2, 3], y=[1, 1, 2], yaxis="y2"), row=1, col=2, secondary_y=True
+    )
+    # add a horizontal line on both subplots on their respective secondary y.
+    # When using the subplots.make_subplots() method yref parameter should NOT be supplied per docstring instructions.
+    # Instead secondary_y specs and secondary_y parameter MUST be True to plot on secondary y
+    fig.add_hline(y=2, row=1, col=1, secondary_y=True)
+    fig.add_hline(y=1, row=1, col=2, secondary_y=True)
+    assert fig.layout["shapes"][0]["yref"] == "y2"
+    assert fig.layout["shapes"][0]["xref"] == "x domain"
+    assert fig.layout["shapes"][1]["yref"] == "y4"
+    assert fig.layout["shapes"][1]["xref"] == "x2 domain"
+
+
 @pytest.fixture
 def select_annotations_integer():
     fig = make_subplots(2, 3)