Instrument readouts and controls

Panel Meter `<smart-panel-meter>`

PanelMeter draws the moving-coil instrument screwed into the front of a rack: a rectangular case, a shallow arc of scale across the top of it and a long needle swinging from a pivot near the bottom.

Getting Started with React PanelMeter Component

The Smart.Industrial React components need React 18 or later, because they render through react-dom/client. The steps use Vite with its react-ts template.

The complete demo in React is on the demo page, file by file.

1 Create a Vite + React + TypeScript app

npm create vite@latest my-smart-app -- --template react-ts

```
cd my-smart-app
```
then
```
npm install
```

2 Install Smart.Industrial

npm install smart-industrial

3 Import styles and render the component

The sample replaces the content of src/App.tsx. It imports the stylesheets and the PanelMeter component, sets the properties the demo sets and handles the change event. It compiles under the template's strict TypeScript settings.

import 'smart-industrial/source/styles/smart.default.css';
import 'smart-industrial/source/styles/smart.industrial-elements.css';
import 'smart-industrial/source/styles/smart.industrial.css';
import { PanelMeter } from 'smart-industrial/react/panelmeter';

function App() {
  // Raised when the reading is changed through the component, which only
  // happens when interactive is enabled.
  const handleChange = (event: CustomEvent) => {
    const { value } = event.detail;
    console.log('change', value);
  };

  return (
    <PanelMeter
      theme="industrial"
      label="Bus"
      unit="V DC"
      min={0}
      max={30}
      value={24.1}
      showValue
      precisionDigits={1}
      interactive
      onChange={handleChange}
    />
  );
}

export default App;

The sample sets interactive because the component takes input from the operator only when it is interactive.

The template's src/main.tsx renders App and needs no change.

Each component has an entry point of its own, and the sample imports from it. The entry point with all the components, smart-industrial/react, puts every component into the bundle, about 2.5 MB minified. Built with Vite, the Faceplate sample has 390 kB of JavaScript, React included, with smart-industrial/react/faceplate.

4 Run the dev server

npm run dev

Vite prints the URL of the application, usually http://localhost:5173/.

TypeScript Support

The types ship with smart-industrial. A type-only import of the component and its props uses import type, which the template's verbatimModuleSyntax requires:

import type { PanelMeter, PanelMeterProps } from 'smart-industrial/react/panelmeter';

Each on* callback receives a CustomEvent whose detail is typed for that event, so the editor lists its fields. A handler typed (event: CustomEvent) => void, as in the sample, accepts it as well.

The keyboard interaction, roles and announcements of the component are on its accessibility page; they are the same in React.