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.

Prerequisites

The connector requires the Proton component to be installed. Normally, Proton is distributed as part of the AppDev pack. See the HCL documentation for instructions on acquiring and installing Proton or the AppDev pack.

Once the Proton service is installed and running, you will also need to create a user account and download its Internet certificate. This certificate can be used to set the connector certificate connection properties.

Authenticating to Domino

• Server: The name or IP address of the server running Domino with the Proton service.
• Port: The port number that the Proton service is listening on.
• Database: The name of the database file, including the .nsf extension.
• SSLClientCertType: This must match the format of the certificate file. Typically this will be either PEMKEY_FILE for .pem certificates or PFXFILE for .pfx certificates.
• SSLClientCert: The path to the certificate file.
• SSLServerCert: This can be set to (*) if you trust the server. This is usually the case, but if you want to perform SSL validation, you may provide a certificate or thumbprint instead. See the documentation for SSLServerCert for details.

Additional Server Configuration

The connector supports querying Domino views if any are defined. Before views can be queried by the connector they must be registered with the design catalog.

Please refer to the Catalog Administration section of the AppDev pack documentation for details on how to do this.

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;Database=names.nsf;Port=3002;SSLClientCertType=PEMKEY_FILE;SSLClientCert=full_path_of_certificate.pem;SSLServerCert=*")

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;Database=names.nsf;Port=3002;SSLClientCertType=PEMKEY_FILE;SSLClientCert=full_path_of_certificate.pem;SSLServerCert=*")

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)