CS Web Proto

This project aims to be able to display control system data on web pages.

It is hosted on Github. It is licensed with the Apache License: see LICENSE.

Setup

See the development environment wiki page for how to get started and notes on development.

Libraries

Runtime

• React is fundamental to the design. Its use of components maps well to the widgets used in control system user interfaces
• Redux also fits well with the design. All control system data may be cached in the global store and widgets will update according to changes to that store

Development

• TypeScript adds some type safety to JavaScript code.
• Create React App - a framework for starting React apps quickly
• Jest is a widely-used testing framework developed by Facebook
• Prettier is used for code formatting

Connection information

This application can use data that come from external sources. These settings will vary from machine to machine, so must, if used, be configured when one checks out the source code.

You needn't set connection information if you don't need any external sources of data; you could just use simulated and local process variables. However, if you want to connect to an external source of data:

• Edit the file .env to contain the correct connection information.
• Restart the process for the settings to take effect.

Coniql

The primary server that you will use is called Coniql. It connects to the EPICS control system and provides data over GraphQL.

For more on how to set up Coniql see this wiki page.

Simulator

There is a built-in simulator that can provide demo data. See this wiki page.

Debugging

The loglevel library is used for logging. To enable this, change the argument to log.setLevel in App.tsx and open the javascript console.

The following log levels are meaningful:

• error: Show errors
• warn: Unexpected but not unrecoverable faults
• info: Log whenever a component changes state (e.g. new subscriptions, new connections.)
• debug: Log every message to the react reducer
• trace: Display data related to network connections.

The debug loglevel is particularly useful since a lot of actions are initiated by a message sent to the reducer. For example, a message is sent to create new subscriptions to process variables, as well as every time a process variable changes value or conneciton status.