Hello,
I’ve come across a strange behavior when updating arrow data with new Bokeh.
These two snippets are equivalent, right?
#1 Updating data by replacing everything:
cds_arrow.data = dict(xS=[0], yS=[1], xE=[new], yE=[1])#2 Updating data by using stream:
cds_arrow.stream(dict(xS=[0], yS=[1], xE=[new], yE=[1]),rollover=1)
However, when using #1, the plot does not update the arrow glyph.
Minimal Example
from bokeh.plotting import figure
from bokeh.models import ColumnDataSource, Slider, Arrow, OpenHead
from bokeh.layouts import column
from bokeh.io import curdoc
cds_arrow = ColumnDataSource(dict(xS=[0], yS=[1], xE=[1], yE=[1]))
cds_line = ColumnDataSource(dict(x=[0,1], y=[3,3]))
def slider_callback_data(attr,old,new):
cds_arrow.data = dict(xS=[0], yS=[1], xE=[new], yE=[1])
cds_line.data = dict(x=[0,new], y=[3,3])
#print(cds_arrow.data) # data is updated but not plotted
def slider_callback_stream(attr,old,new):
cds_arrow.stream(dict(xS=[0], yS=[1], xE=[new], yE=[1]),rollover=1)
cds_line.stream(dict(x=[0,new], y=[3,3]),rollover=2)
slider_data = Slider(title="cds.data", value=1.0, start=0.0, end=5.0, step=0.1, width=400)
slider_data.on_change('value',slider_callback_data)
slider_stream = Slider(title="cds.stream", value=1.0, start=0.0, end=5.0, step=0.1, width=400)
slider_stream.on_change('value',slider_callback_stream)
figure_test = figure(title="Example Figure", x_range=(-1,6), y_range=(-0.5,4.5), height=300, width=400, tools="")
figure_test.line(x='x', y='y', source=cds_line)
arrow_glyph = Arrow(end=OpenHead(), x_start='xS', y_start='yS', x_end='xE', y_end='yE',source=cds_arrow)
figure_test.add_layout(arrow_glyph)
curdoc().add_root(column(figure_test, slider_data, slider_stream))
It definitely worked back in Bokeh 1.0.2 and e.g. for lines it still works in the new Bokeh as you can see in the above minimal example.
Is this a bug or was something changed regarding the Arrow model? I could not find a possible change in the Changelog.
