bokeh JS download columndatasource

download_on_button_example.py

from bokeh.io import curdoc
from bokeh.models.widgets import Button, DataTable, TableColumn
from bokeh.layouts import column, widgetbox
from bokeh.models import ColumnDataSource, CustomJS
import pandas as pd

data_df = pd.DataFrame(dict(A=[0,1,2], B=[3,4,5]))
table_source = ColumnDataSource(data=data_df)
data_table = DataTable(source=table_source, width=200, height=200)
column_list = [TableColumn(field=key, title=key) for key in ['A', 'B']]
data_table.columns = column_list

button = Button(label = 'Dowload')
dowload_source = ColumnDataSource(data=dict())

jscb = CustomJS(args=dict(source=dowload_source), code='''
var txt = source.data['data'][0];
if ((txt != "_begin") && (txt != "_end")) {
        var filename = 'data.csv';
        var blob = new Blob([txt], { type: 'text/csv;charset=utf-8;' });

        //addresses IE
        if (navigator.msSaveBlob) {
            navigator.msSaveBlob(blob, filename);
        }

        else {
            var link = document.createElement("a");
            link = document.createElement('a')
            link.href = URL.createObjectURL(blob);
            link.download = filename
            link.target = "_blank";
            link.style.visibility = 'hidden';
            link.dispatchEvent(new MouseEvent('click'))
        }
}
''')

dowload_source.js_on_change('data', jscb)

def send_data():
    dowload_source.data = {'data': ['_begin']}
    dowload_source.data = {'data': [data_df.to_csv()]}
    dowload_source.data = {'data': ['_end']}

button.on_click(send_data)
curdoc().add_root(column(data_table, widgetbox(button)))
curdoc().add_root(dowload_source)