Bokeh - create custom hovertool for a single glyph on patches figure

Question

I created a map roughly following the texas.py example from Bokeh's documentation. I am trying to add a point on the map that has its own mouseover behavior. I've added the glyph with the following:

bc_glyph = Circle(x=barclays_x, y=barclays_y, size=10, line_color="black", fill_color="silver", line_width=1)

I attempted to create custom HoverTool behavior with this:

bc_ht = HoverTool(renderers=['bc_glyph'], tooltips=['Barclays Stadium'])

Then I called plot.add_glyph(bc_glyph). When running my script, I get the following output:

ValueError: expected an element of either Auto or List(Instance(Renderer)), got ['bc_glyph']

A quick google of the error message leads to Bryan helping another user with a similar issue, so I rewrite as follows:

plot_add = plot.add_glyph(bc_glyph)
bc_ht = HoverTool(renderers=['plot_add'], tooltips=['Barclays Stadium'])

However, that returns the same error:

ValueError: expected an element of either Auto or List(Instance(Renderer)), got ['plot_add']

I understand I have fed the wrong input to renderers, but I'm not sure how to correct this. Any help is appreciated.

Answer 1

You are still passing a string, 'plot_add', as the value. You need to pass the actual variable:

bc_ht = HoverTool(renderers=[plot_add],           # no quote around plot_add
                  tooltips=['Barclays Stadium'])