wp-lcm/fontawesome/icon-migration.php

<?php

//https://github.com/FortAwesome/Font-Awesome/wiki/Upgrading-from-3.2.1-to-4

$icon_migrations = array(
	'ban-circle' => 'ban',
	'bar-chart' => 'bar-chart-o',
	'beaker' => 'flask',
	'bell' => 'bell-o',
	'bell-alt' => 'bell',
	'bitbucket-sign' => 'bitbucket-square',
	'bookmark-empty' => 'bookmark-o',
	'building' => 'building-o',
	'calendar-empty' => 'calendar-o',
	'check-empty' => 'square-o',
	'check-minus' => 'minus-square-o',
	'check-sign' => 'check-square',
	'check' => 'check-square-o',
	'chevron-sign-down' => 'chevron-down',
	'chevron-sign-left' => 'chevron-left',
	'chevron-sign-right' => 'chevron-right',
	'chevron-sign-up' => 'chevron-up',
	'circle-arrow-down' => 'arrow-circle-down',
	'circle-arrow-left' => 'arrow-circle-left',
	'circle-arrow-right' => 'arrow-circle-right',
	'circle-arrow-up' => 'arrow-circle-up',
	'circle-blank' => 'circle-o',
	'cny' => 'rub',
	'collapse-alt' => 'minus-square-o',
	'collapse-top' => 'caret-square-o-up',
	'collapse' => 'caret-square-o-down',
	'comment-alt' => 'comment-o',
	'comments-alt' => 'comments-o',
	'copy' => 'files-o',
	'cut' => 'scissors',
	'dashboard' => 'tachometer',
	'double-angle-down' => 'angle-double-down',
	'double-angle-left' => 'angle-double-left',
	'double-angle-right' => 'angle-double-right',
	'double-angle-up' => 'angle-double-up',
	'download' => 'arrow-circle-o-down',
	'download-alt' => 'download',
	'edit-sign' => 'pencil-square',
	'edit' => 'pencil-square-o',
	'ellipsis-horizontal' => 'ellipsis-h',
	'ellipsis-vertical' => 'ellipsis-v',
	'envelope-alt' => 'envelope-o',
	'exclamation-sign' => 'exclamation-circle',
	'expand-alt' => 'plus-square-o',
	'expand' => 'caret-square-o-right',
	'external-link-sign' => 'external-link-square',
	'eye-close' => 'eye-slash',
	'eye-open' => 'eye',
	'facebook-sign' => 'facebook-square',
	'facetime-video' => 'video-camera',
	'file-alt' => 'file-o',
	'file-text-alt' => 'file-text-o',
	'flag-alt' => 'flag-o',
	'folder-close-alt' => 'folder-o',
	'folder-close' => 'folder',
	'folder-open-alt' => 'folder-open-o',
	'food' => 'cutlery',
	'frown' => 'frown-o',
	'fullscreen' => 'arrows-alt',
	'github-sign' => 'github-square',
	'google-plus-sign' => 'google-plus-square',
	'group' => 'users',
	'h-sign' => 'h-square',
	'hand-down' => 'hand-o-down',
	'hand-left' => 'hand-o-left',
	'hand-right' => 'hand-o-right',
	'hand-up' => 'hand-o-up',
	'hdd' => 'hdd-o',
	'heart-empty' => 'heart-o',
	'hospital' => 'hospital-o',
	'indent-left' => 'outdent',
	'indent-right' => 'indent',
	'info-sign' => 'info-circle',
	'keyboard' => 'keyboard-o',
	'legal' => 'gavel',
	'lemon' => 'lemon-o',
	'lightbulb' => 'lightbulb-o',
	'linkedin-sign' => 'linkedin-square',
	'meh' => 'meh-o',
	'microphone-off' => 'microphone-slash',
	'minus-sign-alt' => 'minus-square',
	'minus-sign' => 'minus-circle',
	'mobile-phone' => 'mobile',
	'moon' => 'moon-o',
	'move' => 'arrows',
	'off' => 'power-off',
	'ok-circle' => 'check-circle-o',
	'ok-sign' => 'check-circle',
	'ok' => 'check',
	'paper-clip' => 'paperclip',
	'paste' => 'clipboard',
	'phone-sign' => 'phone-square',
	'picture' => 'picture-o',
	'pinterest-sign' => 'pinterest-square',
	'play-circle' => 'play-circle-o',
	'play-sign' => 'play-circle',
	'plus-sign-alt' => 'plus-square',
	'plus-sign' => 'plus-circle',
	'pushpin' => 'thumb-tack',
	'question-sign' => 'question-circle',
	'remove-circle' => 'times-circle-o',
	'remove-sign' => 'times-circle',
	'remove' => 'times',
	'reorder' => 'bars',
	'resize-full' => 'expand',
	'resize-horizontal' => 'arrows-h',
	'resize-small' => 'compress',
	'resize-vertical' => 'arrows-v',
	'rss-sign' => 'rss-square',
	'save' => 'floppy-o',
	'screenshot' => 'crosshairs',
	'share-alt' => 'share',
	'share-sign' => 'share-square',
	'share' => 'share-square-o',
	'sign-blank' => 'square',
	'signin' => 'sign-in',
	'signout' => 'sign-out',
	'smile' => 'smile-o',
	'sort-by-alphabet-alt' => 'sort-alpha-desc',
	'sort-by-alphabet' => 'sort-alpha-asc',
	'sort-by-attributes-alt' => 'sort-amount-desc',
	'sort-by-attributes' => 'sort-amount-asc',
	'sort-by-order-alt' => 'sort-numeric-desc',
	'sort-by-order' => 'sort-numeric-asc',
	'sort-down' => 'sort-desc',
	'sort-up' => 'sort-asc',
	'stackexchange' => 'stack-overflow',
	'star-empty' => 'star-o',
	'star-half-empty' => 'star-half-o',
	'sun' => 'sun-o',
	'thumbs-down-alt' => 'thumbs-o-down',
	'thumbs-up-alt' => 'thumbs-o-up',
	'time' => 'clock-o',
	'trash' => 'trash-o',
	'tumblr-sign' => 'tumblr-square',
	'twitter-sign' => 'twitter-square',
	'unlink' => 'chain-broken',
	'upload' => 'arrow-circle-o-up',
	'upload-alt' => 'upload',
	'warning-sign' => 'exclamation-triangle',
	'xing-sign' => 'xing-square',
	'youtube-sign' => 'youtube-square',
	'zoom-in' => 'search-plus',
	'zoom-out' => 'search-minus',
);

function migrate_fontawesome_icon( $current ){
	global $icon_migrations;

	if ( strpos( $current, 'icon-' ) === false ) {
		return $current;
	}

	$old = preg_replace( '/^icon-/', '', $current );

	if ( isset($icon_migrations[ $old ] ) ) {
		$new = $icon_migrations[ $old ];
	}
	else {
		$new = $old;
	}

	return 'fa fa-'. $new;
}

add_filter('vantage_fontawesome_icon_name', 'migrate_fontawesome_icon');