Use Dash to Build to Web Apps on HCL Domino Data

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

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

Connecting to HCL Domino Data

Connecting to HCL Domino 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.

Connecting to Domino

To connect to Domino data, set the following properties:

• URL: The host name or IP of the server hosting the Domino database. Include the port of the server hosting the Domino database. For example: http://sampleserver:1234/
• DatabaseScope: The name of a scope in the Domino Web UI. The driver exposes forms and views for the schema governed by the specified scope. In the Domino Admin UI, select the Scopes menu in the sidebar. Set this property to the name of an existing scope.

Authenticating with Domino

Domino supports authenticating via login credentials or an Azure Active Directory OAuth application:

Login Credentials

To authenticate with login credentials, set the following properties:

• AuthScheme: Set this to "OAuthPassword"
• User: The username of the authenticating Domino user
• Password: The password associated with the authenticating Domino user

The driver uses the login credentials to automatically perform an OAuth token exchange.

AzureAD

This authentication method uses Azure Active Directory as an IdP to obtain a JWT token. You need to create a custom OAuth application in Azure Active Directory and configure it as an IdP. To do so, follow the instructions in the Help documentation. Then set the following properties:

• AuthScheme: Set this to "AzureAD"
• InitiateOAuth: Set this to GETANDREFRESH. You can use InitiateOAuth to avoid repeating the OAuth exchange and manually setting the OAuthAccessToken.
• OAuthClientId: The Client ID obtained when setting up the custom OAuth application.
• OAuthClientSecret: The Client secret obtained when setting up the custom OAuth application.
• CallbackURL: The redirect URI defined when you registered your app. For example: https://localhost:33333
• AzureTenant: The Microsoft Online tenant being used to access data. Supply either a value in the form companyname.microsoft.com or the tenant ID.

  The tenant ID is the same as the directory ID shown in the Azure Portal's Azure Active Directory > Properties page.

After installing the CData HCL Domino Connector, follow the procedure below to install the other required modules and start accessing HCL Domino 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 HCL Domino 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.domino as mod
import plotly.graph_objs as go

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

cnxn = mod.connect("Server=https://domino.corp.com;AuthScheme=OAuthPassword;User=my_domino_user;Password=my_domino_password;")

Execute SQL to HCL Domino

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 Name, Address FROM ByName WHERE City = 'Miami'", 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-dominoedataplot'

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 HCL Domino data and configure the app layout.

trace = go.Bar(x=df.Name, y=df.Address, name='Name')

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='HCL Domino ByName 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 HCL Domino data.

python domino-dash.py

Free Trial & More Information

Download a free, 30-day trial of the CData Python Connector for HCL Domino to start building Python apps with connectivity to HCL Domino 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.domino as mod
import plotly.graph_objs as go

cnxn = mod.connect("Server=https://domino.corp.com;AuthScheme=OAuthPassword;User=my_domino_user;Password=my_domino_password;")

df = pd.read_sql("SELECT Name, Address FROM ByName WHERE City = 'Miami'", cnxn)
app_name = 'dash-dominodataplot'

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.Name, y=df.Address, name='Name')

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='HCL Domino ByName Data', barmode='stack')
		})
], className="container")

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