Bokeh server callback from tools

Question

I'm a little new to Python, and am currently working on interactive visualization of graphs using Bokeh, where I need to show some related graphs. For this, I use a Bokeh server.

I read the documents and some examples, but I could not find an example of a Python callback (executed on the server) caused by a selection on the graph. Basically what I would like to do is something like:

from bokeh.plotting import figure, curdoc
from bokeh.layouts import column
from bokeh.models import ColumnDataSource

TOOLS = "tap"
p = figure(title="Some Figure", tools=TOOLS)

source = ColumnDataSource(dict(x=[[1, 3, 2], [3, 4, 6, 6]], y=[[2, 1, 4], [4, 7, 8, 5]], name=['A', 'B']))

p.patches('x', 'y', source=source, color=["firebrick", "navy"], alpha=[0.8, 0.3], line_width=2)


def callback():
    print("TapTool callback executed on Patch {}")


??? <- some code here linking the taptool with the callback function defined above


curdoc().add_root(column(p))

and then when starting the server and clicking on the patch:

2017-02-14 16: 32: 00,000 TapTool callback made in patch A

can this behavior be achieved with bokeh?

Answer 1

.

, 1.0. 1.0, 'indices' selected " selected:

source.selected.on_change('indices', callback)

, , Bokeh 1.0.

---

selected :

from bokeh.plotting import figure, curdoc
from bokeh.layouts import column
from bokeh.models import ColumnDataSource

TOOLS = "tap"
p = figure(title="Some Figure", tools=TOOLS)

source = ColumnDataSource(dict(x=[[1, 3, 2], [3, 4, 6, 6]],
                y=[[2, 1, 4], [4, 7, 8, 5]], name=['A', 'B']))

pglyph = p.patches('x', 'y', source=source, color=["firebrick", "navy"],
                                alpha=[0.8, 0.3], line_width=2)

def callback(attr, old, new):
    # The index of the selected glyph is : new['1d']['indices'][0]
    patch_name =  source.data['name'][new['1d']['indices'][0]]
    print("TapTool callback executed on Patch {}".format(patch_name))

pglyph.data_source.on_change('selected',callback)

curdoc().add_root(column(p))

Bokeh. 0.12.16

@Karel Marik , ColumnDataSource . . , source ( shift + click):

from bokeh.plotting import figure, curdoc
from bokeh.layouts import column
from bokeh.models import ColumnDataSource

TOOLS = ["tap"]
p = figure(title="Some Figure", tools=TOOLS)

source = ColumnDataSource(dict(
    x=[[1, 3, 2], [3, 4, 6, 6]],
    y=[[2, 1, 4], [4, 7, 8, 5]],
    name=['A', 'B'],color=["firebrick", "navy"],
    alpha=[0.8,0.3],line_width=[3,3]))

pglyph = p.patches('x', 'y', color="color", alpha="alpha",
                   line_width="line_width", source=source)

def callback(attr, old, new):
    # The index of the selected glyph is : new['1d']['indices'][0]
    selections = new['1d']['indices']
    print("Number of selections:{}".format(len(selections)))
    for index in selections:
        patch_name =  source.data['name'][index]
        print("TapTool callback executed on Patch {}".format(patch_name))

pglyph.data_source.on_change('selected',callback)

curdoc().add_root(column(p))

Answer 2

, Pablo, , bokeh (0.12.13). ( )

...

from bokeh.plotting import figure, curdoc
from bokeh.layouts import column
from bokeh.models import ColumnDataSource

TOOLS = "tap"
p = figure(title="Some Figure", tools=TOOLS)

source = ColumnDataSource(dict(x=[[1, 3, 2], [3, 4, 6, 6]], y=[[2, 1, 4], [4, 7, 8, 5]], alphas = [0.8, 0.3], colors=["firebrick", "navy"], name=['A', 'B']))

pglyph = p.patches(xs='x', ys='y', source=source, line_width=2, alpha = 'alphas', color='colors')

def callback_fcn(attr, old, new):
    # The index of the selected glyph is : new['1d']['indices'][0]
    patch_name =  source.data['name'][new['1d']['indices'][0]]
    print("TapTool callback executed on Patch {}".format(patch_name))

pglyph.data_source.on_change('selected',callback_fcn)

curdoc().add_root(column(p))

Answer 3

, 1.0.2 - , ?

Answer 4

Starting with bokeh 0.13, the solution proposed by @Karel_Marik a requires a little tweaking:

from bokeh.plotting import figure, curdoc
from bokeh.layouts import column
from bokeh.models import ColumnDataSource

TOOLS = ["tap"]
p = figure(title="Some Figure", tools=TOOLS)

source = ColumnDataSource(dict(
    x=[[1, 3, 2], [3, 4, 6, 6]],
    y=[[2, 1, 4], [4, 7, 8, 5]],
    name=['A', 'B'],color=["firebrick", "navy"],
    alpha=[0.8,0.3],line_width=[3,3]))

pglyph = p.patches('x', 'y', color="color", alpha="alpha",
                   line_width="line_width", source=source)

def callback(attr, old, new):
    # The index of the selected glyph is : new['1d']['indices'][0]
    selections = new['1d']['indices']
    print("Number of selections:{}".format(len(selections)))
    for index in selections:
        patch_name =  source.data['name'][index]
        print("TapTool callback executed on Patch {}".format(patch_name))

pglyph.data_source.on_change ('selected', callback)

pglyph.selected.on_change('indices', callback)

curdoc().add_root(column(p))

Hope this helps someone.