Modified MediaWiki Echo DiscussionParser to support ScratchSig

DiscussionParser-modified.php

/**
	 * From a line in the signature, extract all the users linked to
	 *
	 * @param string $line Line of text potentially including linked user, user talk,
	 *  and contribution pages
	 * @return string[] array of usernames, empty array for none detected
	 */
	public static function extractUsersFromLine( $line ) {
		/*
		 * Signatures can look like anything (as defined by i18n messages
		 * "signature" & "signature-anon").
		 * A signature can, e.g., be both a link to user & user-talk page.
		 */
		// match all title-like excerpts in this line
		preg_match_all( '/\[\[([^\[]+)\]\]/', $line, $matches );

		$matches = $matches[1];

		$usernames = [];

		foreach ( $matches as $match ) {
			/*
			 * Create an object out of the link title.
			 * In theory, links can be [[text]], [[text|text]] or pipe tricks
			 * [[text|]] or [[|text]].
			 * In the case of reverse pipe trick, the value we use *could* be
			 * empty, but Parser::pstPass2 should have normalized that for us
			 * already.
			 */
			$match = explode( '|', $match, 2 );
			$title = Title::newFromText( $match[0] );

			// figure out if we the link is related to a user
			if (
				$title &&
				( $title->getNamespace() === NS_USER || $title->getNamespace() === NS_USER_TALK )
			) {
				$usernames[] = $title->getText();
			} elseif ( $title && $title->isSpecial( 'Contributions' ) ) {
				$parts = explode( '/', $title->getText(), 2 );
				$usernames[] = end( $parts );
			} else {
				// move on to next matched title-like excerpt
				continue;
			}
		}
		
		preg_match_all('%<scratchsig>(.*?)</scratchsig>%', $line, $matches);
		foreach ($matches[1] as $username) {
		    $usernames[] = User::newFromName($username)->getName();
		}

		return $usernames;
	}