Add wporg/time block

mu-plugins/blocks/time/index.php

@@ -0,0 +1,174 @@
+<?php
+/**
+ * Block Name: Time
+ * Description: Attempts to parse a time string like <code>[time]any-valid-time-string-here[/time]</code> and creates a format that shows it in the viewers local time zone.
+ *
+ * @package wporg
+ */
+
+namespace WordPressdotorg\MU_Plugins\Time;
+
+use function WordPressdotorg\MU_Plugins\Helpers\register_assets_from_metadata;
+
+add_action( 'init', __NAMESPACE__ . '\init' );
+
+/**
+ * Registers the block using the metadata loaded from the `block.json` file.
+ * Behind the scenes, it registers also all assets so they can be enqueued
+ * through the block editor in the corresponding context.
+ *
+ * @see https://developer.wordpress.org/reference/functions/register_block_type/
+ */
+function init() {
+	register_block_type( __DIR__ . '/build' );
+	add_filter('the_content', __NAMESPACE__ . '\transform_time_blocks', 99, 1);
+}
+
+/**
+ * Builds the time block output.
+ *
+ * This implements replacing the raw time strings in the post content with formatted times able to be converted to local times with JS.
+ *
+ * @param string $content Post content.
+ * @return string Content with display times reformatted.
+ */
+function transform_time_blocks( $content) {
+	// Find the time block elements by the classname "wporg-time"
+	$dom = new \DOMDocument();
+	$dom->loadHTML( $content );
+	$xpath = new \DOMXPath( $dom );
+	$time_elements = $xpath->query( "//*[contains(concat(' ', normalize-space(@class), ' '), ' wporg-time ')]" );
+
+	foreach ( $time_elements as $time_element ) {
+		$time_content = $time_element->nodeValue;
+		$parsed_time = parse_time( $time_content );
+
+		if ( $parsed_time === null ) {
+			continue;
+		}
+
+		// Build the link and abbr microformat.
+		$time_element->setAttribute( 'href', 'https://www.timeanddate.com/worldclock/fixedtime.html?iso=' . gmdate( 'Ymd\THi', $parsed_time ) );
+
+		$new_time_content = $dom->createElement( 'abbr', $time_content );
+		$new_time_content->setAttribute( 'class', 'wporg-time-date' );
+		$new_time_content->setAttribute( 'title', gmdate( 'c', $parsed_time ) );
+
+		// Replace the raw time with the formatted time
+		$time_element->nodeValue = null;
+		$time_element->appendChild( $new_time_content );
+	}
+
+	$content = $dom->saveHTML();
+
+	return $content;
+}
+
+/**
+ * Parse the datetime description string and return a timestamp.
+ *
+ * @param string $content Datetime description, eg. `Monday, April 6 at 19:00 UTC`
+ * @return string Unix timestamp or null if the time string could not be parsed.
+ */
+function parse_time( $content ) {
+	// Replace non-breaking spaces with a regular white space.
+	$gmtcontent = preg_replace( '/\xC2\xA0|&nbsp;/', ' ', $content );
+
+	// PHP understands "GMT" better than "UTC" for timezones.
+	$gmtcontent = str_replace( 'UTC', 'GMT', $gmtcontent );
+
+	// Remove the word "at" from the string, if present. Allows strings like "Monday, April 6 at 19:00 UTC" to work.
+	$gmtcontent = str_replace( ' at ', ' ', $gmtcontent );
+
+	// Try to parse the time, relative to the post time.
+	$time = strtotime( $gmtcontent, get_the_date( 'U' ) );
+
+	// If that didn't work, give up.
+	if ( false === $time || -1 === $time ) {
+		return null;
+	}
+
+	// Add the time converter JS code.
+	if ( ! has_action( 'wp_footer', __NAMESPACE__ . '\time_converter_script' ) ) {
+		add_action( 'wp_footer', __NAMESPACE__ . '\time_converter_script', 999 );
+	}
+
+	return $time;
+}
+
+/**
+ * Prints script to convert time in the viewers local time zone.
+ */
+function time_converter_script() {
+	?>
+	<script type="text/javascript" id="time_converter_script">
+		( function() {
+			function convertTime() {
+				const parseDate = function( text ) {
+					var m = /^([0-9]{4})-([0-9]{2})-([0-9]{2})T([0-9]{2}):([0-9]{2}):([0-9]{2})\+00:00$/.exec( text );
+
+					return new Date(
+						// Date.UTC(year, monthIndex (0..11), day, hour, minute, second)
+						Date.UTC( + m[1], + m[2] - 1, + m[3], + m[4], + m[5], + m[6] )
+					);
+				};
+
+				const formatTime = function( d ) {
+					return d.toLocaleTimeString( navigator.language, {
+						weekday     : 'long',
+						month       : 'long',
+						day         : 'numeric',
+						year        : 'numeric',
+						hour        : '2-digit',
+						minute      : '2-digit',
+						timeZoneName: 'short'
+					} );
+				};
+
+				const formatDate = function( d ) {
+					return d.toLocaleDateString( navigator.language, {
+						weekday: 'long',
+						month  : 'long',
+						day    : 'numeric',
+						year   : 'numeric'
+					} );
+				};
+
+				// Not all browsers, particularly Safari, support arguments to .toLocaleTimeString().
+				const toLocaleTimeStringSupportsLocales = (
+					function() {
+						try {
+							new Date().toLocaleTimeString( 'i' );
+						} catch ( e ) {
+							return e.name === 'RangeError';
+						}
+
+						return false;
+					}
+				)();
+
+				document.querySelectorAll('.wporg-time-date').forEach( ( dateElement ) => {
+					let localTime = '';
+					const date = parseDate( dateElement.getAttribute( 'title' ) );
+
+					if ( date ) {
+						if ( ! toLocaleTimeStringSupportsLocales ) {
+							console.log("🚀 ~ file: index.php:143 ~ document.querySelectorAll ~ toLocaleTimeStringSupportsLocales:", toLocaleTimeStringSupportsLocales)
+							localTime += formatDate( date );
+							localTime += ' ';
+						}
+
+						localTime += formatTime( date );
+
+						dateElement.innerText = localTime;
+					}
+				} );
+			}
+
+			document.addEventListener( 'DOMContentLoaded', () => {
+				convertTime();
+			} );
+		} )();
+	</script>
+<?php
+}

mu-plugins/blocks/time/src/block.json

@@ -0,0 +1,11 @@
+{
+	"$schema": "https://schemas.wp.org/trunk/block.json",
+	"apiVersion": 2,
+	"name": "wporg/time",
+	"title": "Time",
+	"icon": "calendar",
+	"category": "common",
+	"description": "Attempts to parse a time string like <code>[time]any-valid-time-string-here[/time]</code> and creates a format that shows it in the viewers local time zone.",
+	"textdomain": "wporg",
+	"editorScript": "file:./index.js"
+}

mu-plugins/blocks/time/src/index.js

@@ -0,0 +1,32 @@
+/**
+ * WordPress dependencies
+ */
+import { registerFormatType, toggleFormat } from '@wordpress/rich-text';
+import { RichTextToolbarButton } from '@wordpress/block-editor';
+
+/**
+ * Internal dependencies
+ */
+import metadata from './block.json';
+
+const Edit = ( { isActive, onChange, value } ) => (
+	<RichTextToolbarButton
+		icon={ metadata.icon }
+		title={ metadata.title }
+		onClick={ () => {
+			onChange(
+				toggleFormat( value, {
+					type: metadata.name,
+				} )
+			);
+		} }
+		isActive={ isActive }
+	/>
+);
+
+registerFormatType( metadata.name, {
+	title: metadata.title,
+	tagName: 'a',
+	className: 'wporg-time',
+	edit: Edit,
+} );

mu-plugins/loader.php

@@ -38,6 +38,7 @@
 require_once __DIR__ . '/blocks/screenshot-preview/block.php';
 require_once __DIR__ . '/blocks/site-breadcrumbs/index.php';
 require_once __DIR__ . '/blocks/table-of-contents/index.php';
+require_once __DIR__ . '/blocks/time/index.php';
 require_once __DIR__ . '/global-fonts/index.php';
 require_once __DIR__ . '/plugin-tweaks/index.php';
 require_once __DIR__ . '/rest-api/index.php';