Use Dash to Build to Web Apps on LINE Data

The rich ecosystem of Python modules lets you get to work quickly and integrate your systems more effectively. With the CData API Driver for Python, the pandas module, and the Dash framework, you can build LINE-connected web applications for LINE data. This article shows how to connect to LINE with the CData Connector and use pandas and Dash to build a simple web app for visualizing LINE data.

With built-in, optimized data processing, the CData Python Connector offers unmatched performance for interacting with live LINE data in Python. When you issue complex SQL queries from LINE, the driver pushes supported SQL operations, like filters and aggregations, directly to LINE and utilizes the embedded SQL engine to process unsupported operations client-side (often SQL functions and JOIN operations).

Connecting to LINE Data

Connecting to LINE data looks just like connecting to any relational data source. Create a connection string using the required connection properties. For this article, you will pass the connection string as a parameter to the create_engine function.

Start by setting the Profile connection property to the location of the LINE Profile on disk (e.g. C:\profiles\LINE.apip). Next, set the ProfileSettings connection property to the connection string for LINE (see below).

LINE API Profile Settings

The LINE Messaging API uses Channel Access Token authentication. To obtain a Channel Access Token:

1. Log in to the LINE Developers Console at https://developers.line.biz
2. Select your provider and open your Messaging API channel.
3. Navigate to the Messaging API tab.
4. Under Channel access token, click Issue to generate a long-lived token.
5. Copy the generated token.

After obtaining your Channel Access Token, set the following connection properties:

• AuthScheme: Set this to APIKey.

Set the following in the ProfileSettings connection property:

• APIKey: Set this to your LINE Channel Access Token.

After installing the CData LINE Connector, follow the procedure below to install the other required modules and start accessing LINE through Python objects.

Install Required Modules

Use the pip utility to install the required modules and frameworks:

pip install pandas
pip install dash
pip install dash-daq

Visualize LINE Data in Python

Once the required modules and frameworks are installed, we are ready to build our web app. Code snippets follow, but the full source code is available at the end of the article.

First, be sure to import the modules (including the CData Connector) with the following:

import os
import dash
import dash_core_components as dcc
import dash_html_components as html
import pandas as pd
import cdata.api as mod
import plotly.graph_objs as go

You can now connect with a connection string. Use the connect function for the CData LINE Connector to create a connection for working with LINE data.

cnxn = mod.connect("Profile=C:\profiles\LINE.apip;ProfileSettings='APIKey=your_channel_access_token;';AuthScheme=APIKey;")

Execute SQL to LINE

Use the read_sql function from pandas to execute any SQL statement and store the result set in a DataFrame.

df = pd.read_sql("SELECT DeliveryDate, DeliveredCount FROM ReplyMessageDelivery WHERE DeliveryDate = '20240115'", cnxn)

Configure the Web App

With the query results stored in a DataFrame, we can begin configuring the web app, assigning a name, stylesheet, and title.

app_name = 'dash-apiedataplot'

external_stylesheets = ['https://codepen.io/chriddyp/pen/bWLwgP.css']

app = dash.Dash(__name__, external_stylesheets=external_stylesheets)
app.title = 'CData + Dash'

Configure the Layout

The next step is to create a bar graph based on our LINE data and configure the app layout.

trace = go.Bar(x=df.DeliveryDate, y=df.DeliveredCount, name='DeliveryDate')

app.layout = html.Div(children=[html.H1("CData Extension + Dash", style={'textAlign': 'center'}),
	dcc.Graph(
		id='example-graph',
		figure={
			'data': [trace],
			'layout':
			go.Layout(title='LINE ReplyMessageDelivery Data', barmode='stack')
		})
], className="container")

Set the App to Run

With the connection, app, and layout configured, we are ready to run the app. The last lines of Python code follow.

if __name__ == '__main__':
    app.run_server(debug=True)

Now, use Python to run the web app and a browser to view the LINE data.

python api-dash.py

Free Trial & More Information

Download a free, 30-day trial of the CData API Driver for Python to start building Python apps with connectivity to LINE data. Reach out to our Support Team if you have any questions.

Full Source Code

import os
import dash
import dash_core_components as dcc
import dash_html_components as html
import pandas as pd
import cdata.api as mod
import plotly.graph_objs as go

cnxn = mod.connect("Profile=C:\profiles\LINE.apip;ProfileSettings='APIKey=your_channel_access_token;';AuthScheme=APIKey;")

df = pd.read_sql("SELECT DeliveryDate, DeliveredCount FROM ReplyMessageDelivery WHERE DeliveryDate = '20240115'", cnxn)
app_name = 'dash-apidataplot'

external_stylesheets = ['https://codepen.io/chriddyp/pen/bWLwgP.css']

app = dash.Dash(__name__, external_stylesheets=external_stylesheets)
app.title = 'CData + Dash'
trace = go.Bar(x=df.DeliveryDate, y=df.DeliveredCount, name='DeliveryDate')

app.layout = html.Div(children=[html.H1("CData Extension + Dash", style={'textAlign': 'center'}),
	dcc.Graph(
		id='example-graph',
		figure={
			'data': [trace],
			'layout':
			go.Layout(title='LINE ReplyMessageDelivery Data', barmode='stack')
		})
], className="container")

if __name__ == '__main__':
    app.run_server(debug=True)