How to update/extend plotly chart

Dash Python
6

Could you give a link to how to include a standalone app?

And I think I’ve got it.
Thank you so much @Emmanuelle

Now I have bugs with autoscroll
That’s what it looks like:

ohlc
ohlc1432×566 1.42 MB

My full code:

import datetime as dt

import dash_core_components as dcc
import dash_html_components as html
import pandas as pd
import plotly.graph_objects as go
import requests
from dash.dependencies import Output, Input, State
from dash.exceptions import PreventUpdate
from dateutil.relativedelta import relativedelta
from django_plotly_dash import DjangoDash
from shares.services import get_board_candles

config = {
    'scrollZoom': True,
    'staticPlot ': True,
    'autosizable': False,
    'showAxisRangeEntryBoxes ': True,
    'displayModeBar': True,
    'displaylogo': False,
    'responsive': True,
    'modeBarButtonsToRemove': ['toImage',
                               'select2d',
                               'lasso2d',
                               'resetScale2d',
                               'hoverCompareCartesian',
                               'hoverClosestCartesian',
                               'toggleSpikelines',
                               ],
}


def get_data_from_moex(security, start=None, end=None):
    interval = 1
    data = None
    if start is None and end is None:
        start = dt.datetime.today()
    if start <= dt.datetime.today():
        start = start.replace(hour=0, minute=0, second=0)
        while not data:
            with requests.Session() as session:
                data = get_board_candles(session, security, interval, start, end)
            if not data:
                start = start - relativedelta(days=1)
                end = start + relativedelta(days=1)
        # Dataframe
        df = pd.DataFrame(data)
        df['datetime'] = pd.to_datetime(df.begin, format='%Y-%m-%d %H:%M')
        if df['datetime'][0].minute == 59:
            df['datetime'] += pd.Timedelta('1 minute')
        del df['begin'], df['value']
        jsonified_df = df.to_json(orient='split')
        return jsonified_df


def load_figure(jsonified_df, graph=None):
    df = pd.read_json(jsonified_df, orient='split')
    fig = go.Figure(
        data=[go.Candlestick(
            dict(x=df['datetime'], open=df['open'], high=df['high'], low=df['low'],
                 close=df['close']))],
        layout=dict(xaxis=dict(autorange=True, rangeslider=dict(visible=False),
                               rangebreaks=[
                                   dict(pattern='hour', bounds=[19, 10])]
                               ),
                    yaxis=dict(autorange=True, overlaying='y', side='right',
                               position=1, tickformat='.2f', ticksuffix='₽'),
                    margin=dict(t=0, b=0, r=40, l=0),
                    autosize=True,
                    hovermode='x', dragmode='pan'
                    )
    )
    return fig


ohlc = DjangoDash('Plot', serve_locally=True, add_bootstrap_links=True)


def serve_layout():
    return html.Div([
        dcc.Graph(id='graph', animate=True, config=config),
        dcc.Store(id='signal', storage_type='media'),
        dcc.Interval(
            id='interval',
            interval=1000,
            n_intervals=0),
    ])


ohlc.layout = serve_layout


@ohlc.callback(Output('graph', 'figure'),
               [Input('signal', 'data')])
def load_graph(signal, *args, **kwargs):
    if signal:
        fig = load_figure(signal)
        return fig


@ohlc.expanded_callback(Output('signal', 'data'),
                        [Input('graph', 'relayoutData')])
def save_in_store(relayout_data, *args, **kwargs):
    security = kwargs['session_state']['security']
    start = None
    end = None
    try:
        x_start = relayout_data['xaxis.range[0]'].split(sep=' ')
        x_end = relayout_data['xaxis.range[1]'].split(sep=' ')
    except (TypeError, KeyError, AttributeError):
        jsonified_df = get_data_from_moex(security)
        return jsonified_df
    else:
        x_start = f'{x_start[0]} {x_start[1].split(sep=":")[0]}'
        x_start = dt.datetime.strptime(x_start, '%Y-%m-%d %H')
        x_end = f'{x_end[0]} {x_end[1].split(sep=":")[0]}'
        x_end = dt.datetime.strptime(x_end, '%Y-%m-%d %H')
        if x_start <= x_start.replace(hour=10):
            start = x_start - relativedelta(days=1)
            end = start + relativedelta(days=2)
        elif x_end >= x_end.replace(hour=19):
            start = x_start + relativedelta(days=1)
            end = start + relativedelta(days=2)
        jsonified_df = get_data_from_moex(security, start, end)
        return jsonified_df


@ohlc.callback(Output('graph', 'extendData'),
               [Input('signal', 'data'), Input('interval', 'n_intervals')],
               [State('graph', 'figure')])
def update_extend_then_add(jsonified_df, n_intervals, graph, *args, **kwargs):
    if graph is None:
        raise PreventUpdate
    if jsonified_df:
        # print((len(jsonified_df.encode("utf-8"))) / 1024, 'kBytes')
        df = pd.read_json(jsonified_df, orient='split')
        x = list(df['datetime'])
        opens = list(df['open'])
        high = list(df['high'])
        low = list(df['low'])
        closes = list(df['close'])
        retval = [dict(
            close=[closes],
            high=[high],
            low=[low],
            open=[opens],
            x=[x]
        )]
        return retval