Web explorer for Sen¶

This web explorer demonstrates how to use the Sen REST API from a browser environment. It provides real-time updates through Server-Sent Events (SSE).

Prerequisites¶

• Docker engine: make sure to follow the installation guide and the post-installation steps
• A running Sen REST component

Example structure¶

web_explorer/
├── index.html          # Web page
├── sen_client.js       # JavaScript client
├── nginx.conf          # nginx configuration
├── run_server.sh       # shell script to run nginx Docker container
└── README.md           # This file

How to run¶

Create a sen configuration file (e.g. config.yaml) to load the REST component:

load:
  - name: rest
    group: 3
    address: "0.0.0.0"
    port: 8080

Note: run_server.sh script expects REST component opens on port 8080.

Now start sen and the web server as follows:

# Run sen with previous configuration
sen run config.yaml

# Run with default port (8000)
./run_server.sh

Open the browser (http://localhost:8000) and developer console to see:

• API request/response details
• SSE event streams
• Error messages
• Object interaction logs

Usage¶

Start session¶

First of all, start session with the Client ID of choice and click Start Session. This step is needed in order to interact with the component.

Next to Start Session button there is a checkbox with the name SSE. This checkbox enables the browser to receive push notifications from the REST component when Sen objects are updated.

Create interest¶

To create an interest, fill both fields in the Interest section. The first field corresponds to the interest name and the second field is for the interest query. The interest query must be written on Sen Query Language. There is a section called Sessions which shows all the available sessions.

Interests are saved until the Sen REST component is ended. To show all the created interests, click Reload on the Available Interests section.

NOTE: To show newly created interests after Reload has already been clicked, refresh the page and click Reload again.

Retrieve objects¶

Once an interest is created, click Retrieve objects in the Available Interests section to show all the objects in that interest.

The Objects section is where object elements will be shown. These include methods, properties and events. To do that, click Get Object. This will show all the object elements classified by type.

For each type of element, different options are available:

• In Object Methods you can get every method definition and invoke them. You can do that by clicking Definition and Invoke buttons respectively. For invoking a method, the arguments must be defined in the Invoke Method Args section.
• In Object Properties you can get every property value and subscribe or unsubscribe to them. To do that, click Get Value, Subscribe and Unsubscribe buttons respectively.
• In Object Events you can subscribe or unsubscribe to an event by clicking Subscribe and Unsubscribe buttons respectively.