> ## Documentation Index
> Fetch the complete documentation index at: https://docs.appsignal.com/llms.txt
> Use this file to discover all available pages before exploring further.

# @appsignal/preact

export const VersionRequirements = ({versions = []}) => {
  if (!Array.isArray(versions) || versions.length === 0) {
    return null;
  }
  const boundaries = {
    upper: " or lower",
    exact: "",
    lower: " or higher"
  };
  const containerStyle = {
    marginTop: "0.5rem",
    marginBottom: "1.5rem"
  };
  const lineStyle = {
    display: "block",
    margin: "0 0 0.35rem 0",
    fontSize: "0.875rem",
    lineHeight: "1.4"
  };
  const pillBaseStyle = {
    display: "inline-block",
    padding: "0.1em 0.4em",
    borderRadius: "0.25rem",
    border: "1px solid",
    fontFamily: "ui-monospace, SFMono-Regular, Menlo, monospace",
    fontSize: "0.85em",
    fontWeight: 500
  };
  const pillColors = {
    "AppSignal for Elixir": {
      background: "#f3e8ff",
      borderColor: "#e9d5ff",
      color: "#9333ea"
    },
    "AppSignal for Front-end": {
      background: "#fef9c3",
      borderColor: "#fde68a",
      color: "#ca8a04"
    },
    "AppSignal for Go": {
      background: "#ccfbf1",
      borderColor: "#99f6e4",
      color: "#0d9488"
    },
    "AppSignal for JavaScript": {
      background: "#fef9c3",
      borderColor: "#fde68a",
      color: "#ca8a04"
    },
    "AppSignal for Node.js": {
      background: "#dcfce7",
      borderColor: "#bbf7d0",
      color: "#16a34a"
    },
    "AppSignal for Python": {
      background: "#dbeafe",
      borderColor: "#bfdbfe",
      color: "#2563eb"
    },
    "AppSignal for Ruby": {
      background: "#fee2e2",
      borderColor: "#fecaca",
      color: "#dc2626"
    },
    "AppSignal for Rust": {
      background: "#ffedd5",
      borderColor: "#fed7aa",
      color: "#ea580c"
    }
  };
  const defaultPillColor = {
    background: "#f4f4f5",
    borderColor: "#e4e4e7",
    color: "#52525b"
  };
  const getPillStyle = name => ({
    ...pillBaseStyle,
    ...pillColors[name] || defaultPillColor
  });
  const getBoundText = bound => {
    return boundaries[bound] || boundaries.lower;
  };
  return <div style={containerStyle}>
      {versions.map((v, i) => <p key={`${v.name}-${v.version}-${v.bound || "lower"}-${i}`} style={lineStyle}>
          This feature requires{" "}
          <code style={getPillStyle(v.name)}>{v.name}</code> version {v.version}
          {getBoundText(v.bound)}.
        </p>)}
    </div>;
};

<VersionRequirements
  versions={[
{ name: "Preact", version: "10.0.0" }
]}
/>

## Installatie

### Met npm of yarn

Voeg de pakketten `@appsignal/preact` en `@appsignal/javascript` toe aan uw `package.json`. Voer vervolgens `npm install`/`yarn install` uit.

U kunt deze pakketten ook via de command line aan uw `package.json` toevoegen:

<CodeGroup>
  ```sh Shell theme={null}
  yarn add @appsignal/javascript @appsignal/preact
  npm install @appsignal/javascript @appsignal/preact
  ```
</CodeGroup>

### Met JSPM.io import maps

Met de [JSPM.io import map generator](https://generator.jspm.io/) kunt u een import map genereren voor de afhankelijkheden van uw applicatie.

Voeg `@appsignal/javascript` en `@appsignal/preact` toe aan de lijst met dependencies in de generator, en voeg vervolgens de gegenereerde import map en ES module shims toe aan de code van uw applicatie.

### Met `rails-importmap`

Gebruik het volgende commando om deze pakketten toe te voegen aan de import maps van uw Rails-applicatie:

<CodeGroup>
  ```sh Shell theme={null}
  ./bin/importmap pin @appsignal/javascript @appsignal/preact
  ```
</CodeGroup>

## Gebruik

### Error Boundary

Als u Preact v10.0.0 of hoger gebruikt, kunt u de `ErrorBoundary`-component gebruiken om fouten van overal in de boom met onderliggende componenten op te vangen.

<CodeGroup>
  ```jsx JavaScript theme={null}
  import { Component } from "preact";

  import { appsignal } from "./appsignal";
  import { ErrorBoundary } from "@appsignal/preact";

  const FallbackComponent = () => (
    <div>Uh oh! There was an error :(</div>
  );

  export default class App extends Component {
    render() {
      return (
        <ErrorBoundary
          instance={appsignal}
          tags={{ tag: "value" }} {/* Optional */}
          fallback={(error) => <FallbackComponent />} {/* Optional */}
        >
          { /** Child components here **/}
        </ErrorBoundary>
      )
    }
  }
  ```
</CodeGroup>