How to add legend and hover tooltips to Bokeh objects created through a function?

[ScarletMcLearn]

Hello.

Hope you are all well.

I have created a Python function which creates a bokeh object.

Using this function, I can generate multiple objects - lines, shapes - on the same figure.

I have been trying to add legends and hover tools to the objects generated by the function, but having issues.

I am providing the code below for your reference:

# Function to generate shapes
def draw_shape(figure, source, x_col_name, y_col_name, shape, size, fill_color, border_color, border_width, alpha, line_dash, line_alpha, line_cap, line_join, line_smoothing, 
               # legend_location, legend_click_property
              ):
    if shape=='circle' or shape=='c':
        figure.circle(x=x_col_name, y=y_col_name, source=source, size=size, fill_color=fill_color, line_color=border_color, line_width=border_width, alpha=alpha)
    elif shape=='square' or shape=='s':
        figure.square(x=x_col_name, y=y_col_name, source=source, size=size, fill_color=fill_color, line_color=border_color, line_width=border_width, alpha=alpha)
    elif shape=='diamond' or shape=='d':
        figure.diamond(x=x_col_name, y=y_col_name, source=source, size=size, fill_color=fill_color, line_color=border_color, line_width=border_width, alpha=alpha)
    elif shape=='triangle' or shape=='t':
        figure.triangle(x=x_col_name, y=y_col_name, source=source, size=size, fill_color=fill_color, line_color=border_color, line_width=border_width, alpha=alpha)
    elif shape=='cross' or shape=='+':
        figure.cross(x=x_col_name, y=y_col_name, source=source, size=size,  fill_color=fill_color, 
                line_color=border_color, line_width=border_width, alpha=alpha)
    elif shape=='X' or shape=='x':
        figure.x(x=x_col_name, y=y_col_name, source=source, size=size,  fill_color=fill_color, 
                line_color=border_color, line_width=border_width, alpha=alpha)
    elif shape=='asterisk' or shape=='*':
        figure.asterisk(x=x_col_name, y=y_col_name, source=source, size=size,  fill_color=fill_color, 
                line_color=border_color, line_width=border_width, alpha=alpha)
    elif shape=='circle_cross' or shape=='c+':
        figure.circle_cross(x=x_col_name, y=y_col_name, source=source, size=size,  fill_color=fill_color, 
                line_color=border_color, line_width=border_width, alpha=alpha)
    elif shape=='circle_x' or shape=='cx':
        figure.circle_x(x=x_col_name, y=y_col_name, source=source, size=size,  fill_color=fill_color, 
                line_color=border_color, line_width=border_width, alpha=alpha)
    elif shape=='inverted_triangle' or shape=='it':
        figure.inverted_triangle(x=x_col_name, y=y_col_name, source=source,  size=size, fill_color=fill_color, 
                line_color=border_color, line_width=border_width, alpha=alpha)
    elif shape=='square_cross' or shape=='s+':
        figure.square_cross(x=x_col_name, y=y_col_name, source=source, size=size,  fill_color=fill_color, 
                line_color=border_color, line_width=border_width, alpha=alpha)
    elif shape=='square_x' or shape=='sx':
        figure.square_x(x=x_col_name, y=y_col_name, source=source, size=size,  fill_color=fill_color, 
                line_color=border_color, line_width=border_width, alpha=alpha)
    elif shape=='plus' or shape=='p':
        figure.plus(x=x_col_name, y=y_col_name, source=source, size=size,  fill_color=fill_color, 
                line_color=border_color, line_width=border_width, alpha=alpha)
    elif shape=='diamond_cross' or shape=='d+':
        figure.diamond_cross(x=x_col_name, y=y_col_name, source=source, size=size,  fill_color=fill_color, 
                line_color=border_color, line_width=border_width, alpha=alpha)
    elif shape=='diamond_x' or shape=='dx':
        figure.diamond_x(x=x_col_name, y=y_col_name, source=source, size=size,  fill_color=fill_color, 
                line_color=border_color, line_width=border_width, alpha=alpha)
    elif shape=='hex' or shape=='h':
        figure.hex(x=x_col_name, y=y_col_name, source=source, size=size,  fill_color=fill_color, 
                line_color=border_color, line_width=border_width, alpha=alpha)
    elif shape=='y':
        figure.y(x=x_col_name, y=y_col_name, source=source, size=size,  fill_color=fill_color, 
                line_color=border_color, line_width=border_width, alpha=alpha)
    elif shape=='-' or shape=='dash':
        figure.dash(x=x_col_name, y=y_col_name, source=source, size=size,  fill_color=fill_color, 
                line_color=border_color, line_width=border_width, alpha=alpha)
    # Modifying
    # elif shape=='line' or shape=='l':
        # Line cap / line join : "butt", "round", or "square"
        # miter, round or bevel
    figure.line(x=x_col_name, y=y_col_name, source=source, #size=size, 
               # fill_color=fill_color, 
                line_color='white', 
                line_width=7, 
                # alpha=1, line_dash=line_dash, 
                line_alpha=1,  
                line_cap=line_cap, line_join=line_join, 
               # line_smoothing=line_smoothing
              )
    # figure.legend.location = legend_location
    # figure.legend.click_policy = legend_click_property
    return figure


# Initializing figure
p = figure(
    title="Dhaka Stock Exchange Live Change",
    x_axis_type="datetime",
    sizing_mode="scale_both",
    max_width=900,
    max_height=300,
    width=900,
    height=900
)

# Drawing Shapes :  
line1 = draw_shape(x_col_name='x_values', y_col_name='y_1_values', source=source, figure=p, shape='c', size=30, fill_color='blue', border_color='white', border_width=3, alpha=0.3, line_smoothing=0.9, line_join='round', line_cap='round', line_alpha=0.6, line_dash='4 4', )

circle1 = draw_shape(x_col_name='x_values', y_col_name='y_1_values', source=source, figure=p, shape='line', size=30, fill_color='blue', border_color='pink', border_width=3, alpha=0.3, line_smoothing=1, line_join='round', line_cap='round', line_alpha=0.9, line_dash='4 4')

p.xaxis.formatter = DatetimeTickFormatter(hours="%H:%M")

# p.legend.title = 'Lines'
# p.legend.location = "top_left"

# legend = Legend(items=[
#     ("Line 1", [line1]),
#     ("Line 2", [circle1])
# ])

# p.add_layout(legend, 'right')

curdoc().theme = 'dark_minimal'
show(p)

If I uncomment the legend code, I get this error -
ValueError: failed to validate Legend(id='p13230', ...).items: expected an element of List(Instance(LegendItem)), got seq with invalid items [('Line 1', [figure(id='p12674', ...)]), ('Line 2', [figure(id='p12674', ...)])]

In a similar way, if I try to use Hover tools :

from bokeh.models import HoverTool
# Define tooltips
tooltips = [
    ("Date", "@x_values{%Y-%m-%d %H:%M}"),
    ("Value", "@y_2_values"),
]


hover_tool = HoverTool(renderers=[line1, 
                                  # line2
                                 ], tooltips=tooltips, formatters={"@x_values": "datetime"})
p.add_tools(hover_tool)


# Define tooltips
tooltips = [
    ("Date", "@x_values{%Y-%m-%d %H:%M}"),
    ("Value", "@y_1_values"),
]

# Add tooltips to both lines
hover_tool_2 = HoverTool(renderers=[circle1, 
                                  # line2
                                 ], tooltips=tooltips, formatters={"@x_values": "datetime"})
p.add_tools(hover_tool_2)

I get this error:
ValueError: failed to validate HoverTool(id='p13006', ...).renderers: expected an element of either Auto or List(Instance(DataRenderer)), got [figure(id='p12674', ...)]

Can you please guide me what is wrong here and how to fix it?

Thank you so much.

[ScarletMcLearn]

Fixed it through this:

def draw_shape(figure, source, x_col_name, y_col_name, shape, size, fill_color, border_color, border_width, alpha, line_dash, line_alpha, line_cap, line_join, line_smoothing):
    if shape=='circle' or shape=='c':
        item = figure.circle(x=x_col_name, y=y_col_name, source=source, size=size, fill_color=fill_color, line_color=border_color, line_width=border_width, alpha=alpha)
    elif shape=='square' or shape=='s':
        item = figure.square(x=x_col_name, y=y_col_name, source=source, size=size, fill_color=fill_color, line_color=border_color, line_width=border_width, alpha=alpha)
    elif shape=='diamond' or shape=='d':
        item = figure.diamond(x=x_col_name, y=y_col_name, source=source, size=size, fill_color=fill_color, line_color=border_color, line_width=border_width, alpha=alpha)
    elif shape=='triangle' or shape=='t':
        item = figure.triangle(x=x_col_name, y=y_col_name, source=source, size=size, fill_color=fill_color, line_color=border_color, line_width=border_width, alpha=alpha)
    elif shape=='cross' or shape=='+':
        item = figure.cross(x=x_col_name, y=y_col_name, source=source, size=size,  fill_color=fill_color, 
                line_color=border_color, line_width=border_width, alpha=alpha)
    elif shape=='X' or shape=='x':
        item = figure.x(x=x_col_name, y=y_col_name, source=source, size=size,  fill_color=fill_color, 
                line_color=border_color, line_width=border_width, alpha=alpha)
    elif shape=='asterisk' or shape=='*':
        item = figure.asterisk(x=x_col_name, y=y_col_name, source=source, size=size,  fill_color=fill_color, 
                line_color=border_color, line_width=border_width, alpha=alpha)
    elif shape=='circle_cross' or shape=='c+':
        item = figure.circle_cross(x=x_col_name, y=y_col_name, source=source, size=size,  fill_color=fill_color, 
                line_color=border_color, line_width=border_width, alpha=alpha)
    elif shape=='circle_x' or shape=='cx':
        item = figure.circle_x(x=x_col_name, y=y_col_name, source=source, size=size,  fill_color=fill_color, 
                line_color=border_color, line_width=border_width, alpha=alpha)
    elif shape=='inverted_triangle' or shape=='it':
        item = figure.inverted_triangle(x=x_col_name, y=y_col_name, source=source,  size=size, fill_color=fill_color, 
                line_color=border_color, line_width=border_width, alpha=alpha)
    elif shape=='square_cross' or shape=='s+':
        item = figure.square_cross(x=x_col_name, y=y_col_name, source=source, size=size,  fill_color=fill_color, 
                line_color=border_color, line_width=border_width, alpha=alpha)
    elif shape=='square_x' or shape=='sx':
        item = figure.square_x(x=x_col_name, y=y_col_name, source=source, size=size,  fill_color=fill_color, 
                line_color=border_color, line_width=border_width, alpha=alpha)
    elif shape=='plus' or shape=='p':
        item = figure.plus(x=x_col_name, y=y_col_name, source=source, size=size,  fill_color=fill_color, 
                line_color=border_color, line_width=border_width, alpha=alpha)
    elif shape=='diamond_cross' or shape=='d+':
        item = figure.diamond_cross(x=x_col_name, y=y_col_name, source=source, size=size,  fill_color=fill_color, 
                line_color=border_color, line_width=border_width, alpha=alpha)
    elif shape=='diamond_x' or shape=='dx':
        item = figure.diamond_x(x=x_col_name, y=y_col_name, source=source, size=size,  fill_color=fill_color, 
                line_color=border_color, line_width=border_width, alpha=alpha)
    elif shape=='hex' or shape=='h':
        item = figure.hex(x=x_col_name, y=y_col_name, source=source, size=size,  fill_color=fill_color, 
                line_color=border_color, line_width=border_width, alpha=alpha)
    elif shape=='y':
        item = figure.y(x=x_col_name, y=y_col_name, source=source, size=size,  fill_color=fill_color, 
                line_color=border_color, line_width=border_width, alpha=alpha)
    elif shape=='-' or shape=='dash':
        item = figure.dash(x=x_col_name, y=y_col_name, source=source, size=size,  fill_color=fill_color, 
                line_color=border_color, line_width=border_width, alpha=alpha)
    elif shape=='line' or shape=='l':
        # Line cap / line join : "butt", "round", or "square"
        # miter, round or bevel
        item = figure.line(x=x_col_name, y=y_col_name, source=source, #size=size, 
               # fill_color=fill_color, 
                line_color=border_color, line_width=border_width, alpha=alpha, line_dash=line_dash, line_alpha=alpha,  line_cap=line_cap, line_join=line_join, 
               # line_smoothing=line_smoothing
              )
        # Final line
    # figure.line(x=x_col_name, y=y_col_name, source=source, #size=size, 
    #            # fill_color=fill_color, 
    #             line_color=border_color, line_width=border_width, alpha=alpha, line_dash=line_dash, line_alpha=alpha,  line_cap=line_cap, line_join=line_join, 
               # line_smoothing=line_smoothing
              # )
    return figure, item

# Perfection Here