react-text2speech

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Introduction

A React Component that leverages WEB Speech API to implement a multi featured text reader/ text highlighter - Just 236kB of weight.

Features:

Dev features:

• Voice language customization
• Theme customization

User features

• Highlight of text during reading
• Highlight style customization ( brush style, colors, underline, etc... )
• Full control on timeline by sliding the seekbar or by manually clicking on text words
• Preview of reading time ( time is averagely calculated )
• Control reading speed
• Select voice type and language
• Control volume and pitch
• Light/Dark mode

Notes

Since the speech engine behaves differently on mobile browsers or according to the selected language, there are some optimization workaround to prevent special characters like "/" or "-" to send out of sync the highlighting of text. There surely are some cases that have not yet been taken into account, if you are experiencing any problem you are kindly asked to open an issue. Stuff inside <code> tags won't be parsed and the engine is not going to read it, for the same reason stated above. More info are provided in the Edge Cases section.

Install

npm install --save react-text2speech

Or with yarn:

yarn add react-text2speech

Usage

Check the example folder for a comprehensive example of how to import and use the React Component in your application.

1. Import the Component and hook that exports some methods and state variables that lets you control the reader:

import TextReader, { useTextReader } from 'react-text2speech';

2. The hook returns a set of state variables and some handlers which are also used internally by the TextReader Component and a bindReader method which has to be passed to the Textreader as a prop in order to be able to bind your Application state to the Reader state:

const { bindReader, handlers, state } = useTextReader();
const { play, pause, showReader, hideReader, minimizeReader, maximizeReader } = handlers;
const { isReading, isLoading, isVisible } = state;

3. The basic usage is:

const [node, setNode] = useState(null);

Then return:

<div ref={setNode}>Some text to be read here</div>
{node && <TextReader textContainer={node} />}

Where node must be an HTMLElement containing the text or HTML child nodes containing text, that you want to be read. Since in React the DOM refs receive the reference to the DOM element after the first render, the best way to pass the ref to the TextReader Component is setting it as a React State.

4. A more complex usage, as the one showed in the example folder leverages the "useTextReader" hook:

	const [node, setNode] = useState(null);

	const { bindReader, handlers, state } = useTextReader();

	const { play, pause, showReader } = handlers;
	const { isReading, isLoading, isVisible } = state;

	return (
		<div>		
			{node && (
				<TextReader
					textContainer={node}
					options={{ language: 'en' }}
					bindReader={bindReader}
				/>
			)}
			<button
				className={styles.play}
				onClick={
					isReading
						? pause
						: () => {
								if (!isVisible) showReader();
								play();
						  }
				}
			>
				{isReading ? 'Pause' : 'Play'}
			</button>
			{isLoading && <div className="loader">Loading...</div>}
			<div ref={setNode}>
				<h1>Ut vero dolorem ea illum fugit.</h1>
			</div>
		</div>
	)

If you are using NextJS and you have issues importing it properly try this way:

const TextReader = dynamic(() => import("react-text2speech"), {
  ssr: false,
});
const { useTextReader } = require("react-text2speech");

Since this module exports both a default and a named export, and NextJS doesn't like that.

5. The TextReader Component expects just the textContainer prop as required, you can pass two extra props though to tweak style and options:

API / Props

Props	Default value	Required	Type
textContainer	undefined	true	HTMLElement
bindReader	undefined	false	function
styleOptions	{ primaryColor: '#00D', secondaryColor: '#55F', bgColor: '#FFF', textColor: '#222', highlightColor1: '#306EFF', highlightColor2: '#FCDFFF', }	false	object
options	{ language: 'en' }	false	object

**Remember to set the language accordingly to the language of the text that it's going to be read, it's enough you type the first locale letters e.g. "en", "de", "fr", etc... **

Browser Support

Browser support is tightly dependant from the official browser implementation of SpeechSynthesis API, Chrome and Edge, Chromium Based browsers, are the most reliable, Firefox has some issues on Linux/Mac during the voices retrieval: https://bugzilla.mozilla.org/show_bug.cgi?id=1432719 and in the management of the utterance events, hence there have been some polyfills implemented to improve the consistency of behaviour on Firefox. Safari still does not support lookbehind assertions so it forced to use some workarounds to perform text parsing to extract chunks. It still has several bugs triggered by seeking and utterance edit actions that have to be addressed. Opera does not support SpeechSynthesis API. Chrome Android supports the player, but only in chunks mode (fixed to enabled on mobile devices), since the 'boundary` event is not implemented in mobile browsers.

Edge Cases

There are some edge cases not yet covered and hardly coverable with extreme precision since the speech synth handles some special characters like "/" or "." and "," in numbers ( 1.000 , 1,000 ) in different ways depending on the language choosen, some locales use "." for decimals, others use ",". Some cases are automatically covered during the content parsing, for example if you happen to have grammar inconsistencies like "word , word" instead of "word, word", they are going to be fixed automatically. Some edge cases like dots in the middle of word like "some.word" are going to be parsed and spelled as "dot" in english, while dots used as punctuation marks won't be read by the synth. These are currently the issues and edge cases not yet covered:

• Punctuation marks directly after an HTML tag won't be taken into account as a chunk delimiter.
• Text inside pre or code tags is skipped.

License

MIT © react-text2speech