Hover tool doesn't work for plots added inside callback

I am experiencing strange behaviour, the hover tool doesn’t show tooltips when created inside a callback. Here is the simplest example:

from bokeh.plotting import Figure, curdoc
from bokeh.layouts import column
from bokeh.models.tools import HoverTool
from bokeh.resources import CDN
from bokeh.embed import server_document, server_session
from bokeh.client import push_session
from bokeh.models import Button
doc = curdoc()
button = Button(label='Add Plot', button_type="success", name='my_button'
)
plots_layout = column(button)
def callback():
    hover = HoverTool(tooltips='hi'    )
plot = Figure()
plot.add_tools(hover)
plots_layout.children.append(plot)
plot.line([1, 2], [1, 2
])
button.on_click(callback)
doc.add_root(plots_layout)
session = push_session(curdoc())
session.show()
session.loop_until_closed()

Interesting that it works after refreshing the page.

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Adding versions of the software:

• python 3.5

• bokeh 0.12.9

• Latest Chrome and Firefox

There were no errors neither from python side or javascript side.

Will be happy to hear how to fix this. Thank you!

Hi Dmitriy,

One way to get the tooltips to appear correctly is to set the renderers property on the hover tool explicitly. This seems to work for me:

def callback():
plot = Figure()
r = plot.line([1, 2], [1, 2])
hover = HoverTool(tooltips=“hi”, renderers=[r])
plot.add_tools(hover)
plots_layout.children.append(plot)

``

Hope this helps,

Claire

Claire,

Thanks for your response.

In my project, I’d like to add lines to plot dynamically meaning that I don’t know in advance the renderer. I tried to add the renderer after but it doesn’t seem to work:

def callback():
    hover = HoverTool(tooltips='hi'    )
plot = Figure()
plot.add_tools(hover)
plots_layout.children.append(plot)
# This happens in another part of code:
    line = plot.line([1, 2], [1, 2    ])
hover.renderers.append(line)

Should I refresh/update something?

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