React component to highlight words within a larger body of text.

Check out a demo [here](https://bvaughn.github.io/react-highlight-words).

## Usage

To use it, just provide it with an array of search terms and a body of text to highlight.

[Try this example in Code Sandbox.](https://codesandbox.io/s/5v8yqoxv7k)

```jsx
import React from "react";
import { createRoot } from "react-dom/client";
import Highlighter from "react-highlight-words";

const root = createRoot(document.getElementById("root"));
root.render(
  <Highlighter
    highlightClassName="YourHighlightClass"
    searchWords={["and", "or", "the"]}
    autoEscape={true}
    textToHighlight="The dog is chasing the cat. Or perhaps they're just playing?"
  />
);
```

And the `Highlighter` will mark all occurrences of search terms within the text:

screen shot 2015-12-19 at 8 23 43 am

## Props

| Property | Type | Required? | Description |
|:---|:---|:---:|:---|
| activeClassName | String |  | The class name to be applied to an active match. Use along with `activeIndex` |
| activeIndex | Number |  | Specify the match index that should be actively highlighted. Use along with `activeClassName` |
| activeStyle | Object |  | The inline style to be applied to an active match. Use along with `activeIndex` |
| autoEscape | Boolean |  | Escape characters in `searchWords` which are meaningful in regular expressions |
| className | String |  | CSS class name applied to the outer/wrapper `<span>` |
| caseSensitive | Boolean |  | Search should be case sensitive; defaults to `false` |
| findChunks | Function |  | Use a custom function to search for matching chunks. This makes it possible to use arbitrary logic when looking for matches. See the default `findChunks` function in [highlight-words-core](https://github.com/bvaughn/highlight-words-core) for signature. Have a look at the [custom findChunks example](https://codesandbox.io/s/k20x3ox31o) on how to use it. |
| highlightClassName | String or Object |  | CSS class name applied to highlighted text or object mapping search term matches to class names. |
| highlightStyle | Object |  | Inline styles applied to highlighted text |
| highlightTag | Node or String |  | Type of tag to wrap around highlighted matches. Defaults to `mark` but can also be a React element (class or functional) |
| sanitize | Function |  | Process each search word and text to highlight before comparing (eg remove accents); signature `(text: string): string` |
| searchWords | Array<String | RegExp> | ✓ | Array of search words. String search terms are automatically cast to RegExps unless `autoEscape` is true. |
| textToHighlight | String | ✓ | Text to highlight matches in |
| unhighlightClassName | String |  | CSS class name applied to unhighlighted text |
| unhighlightStyle | Object |  | Inline styles applied to unhighlighted text |
| unhighlightTag | Node or String |  | Type of tag applied to unhighlighted parts. Defaults to `span` but can also be a React element (class or functional) |
| * | any | | Any other props (such as `title` or `data-*`) are applied to the outer/wrapper `<span>` |

## Custom highlight tag

By default this component uses an HTML Mark Text element (`<mark>`) to wrap matched text, but you can inject a custom
tag using the `highlightTag` property. This tag should be a React component that accepts the following properties:

| Property | Type | Description |
|:---|:---|:---|
| children | String | Text to be highlighted |
| highlightIndex | Number | Index of matched text |

For example:

```js
const Highlight = ({ children, highlightIndex }) => (
  <strong className="highlighted-text">{children}</strong>
);
```

## Installation

```
yarn add react-highlight-words
```

```
npm i --save react-highlight-words
```

## License

MIT License - fork, modify and use however you want.
