@wordpress/block-library/src/file/utils.js

Block library for the WordPress editor.

/**
 * Uses a combination of user agent matching and feature detection to determine whether
 * the current browser supports rendering PDFs inline.
 *
 * @return {boolean} Whether or not the browser supports inline PDFs.
 */
export const browserSupportsPdfs = () => {
	// Most mobile devices include "Mobi" in their UA.
	if ( window.navigator.userAgent.indexOf( 'Mobi' ) > -1 ) {
		return false;
	}

	// Android tablets are the noteable exception.
	if ( window.navigator.userAgent.indexOf( 'Android' ) > -1 ) {
		return false;
	}

	// iPad pretends to be a Mac.
	if (
		window.navigator.userAgent.indexOf( 'Macintosh' ) > -1 &&
		window.navigator.maxTouchPoints &&
		window.navigator.maxTouchPoints > 2
	) {
		return false;
	}

	// IE only supports PDFs when there's an ActiveX object available for it.
	if (
		!! ( window.ActiveXObject || 'ActiveXObject' in window ) &&
		! (
			createActiveXObject( 'AcroPDF.PDF' ) ||
			createActiveXObject( 'PDF.PdfCtrl' )
		)
	) {
		return false;
	}

	return true;
};

/**
 * Helper function for creating ActiveX objects, catching any errors that are thrown
 * when it's generated.
 *
 * @param {string} type The name of the ActiveX object to create.
 * @return {window.ActiveXObject|undefined} The generated ActiveXObject, or null if it failed.
 */
const createActiveXObject = ( type ) => {
	let ax;
	try {
		ax = new window.ActiveXObject( type );
	} catch ( e ) {
		ax = undefined;
	}
	return ax;
};

/**
 * Hides all .wp-block-file__embed elements on the document. This function is only intended
 * to be run on the front-end, it may have weird side effects running in the block editor.
 */
export const hidePdfEmbedsOnUnsupportedBrowsers = () => {
	if ( ! browserSupportsPdfs() ) {
		const embeds = document.getElementsByClassName(
			'wp-block-file__embed'
		);
		Array.from( embeds ).forEach( ( embed ) => {
			embed.style.display = 'none';
		} );
	}
};