schema_TinyMCE_init

functions.php

<?php 
function tsm_get_extended_valid_elements() {
    $elements = array(
        '@' => array(
            'id',
            'class',
            'style',
            'title',
            'itemscope',
            'itemtype',
            'itemprop',
            'datetime',
            'rel'
        ),
        'article', 'div', 'p', 'dl', 'dt', 'dd', 'ul', 'li', 'span',
        'a' => array(
            'href',
            'name',
            'target',
            'rev',
            'charset',
            'lang',
            'tabindex',
            'accesskey',
            'type',
            'class',
            'onfocus',
            'onblur'
        ),
        'img' => array(
            'src',
            'alt',
            'width',
            'height'
        ),
        'meta' => array(
            'content'
        ),
        'link' => array(
            'href'
        ),
        'time' => array(
            'itemprop',
            'content'
        )
    );

    return apply_filters( 'tsm_extended_valid_elements', $elements );
}

function tsm_tinymce_init( $settings )
{
    if( !empty( $settings['extended_valid_elements'] ) ) {
        $settings['extended_valid_elements'] .= ',';
    } else {
        $settings['extended_valid_elements'] = '';
    }

    $result = $settings['extended_valid_elements'];

    $elements = tsm_get_extended_valid_elements();

    foreach ( $elements as $key => $element ) {
        if ( is_array( $element ) && !empty( $key ) ) {
            $name = $key;
            $attributes = $element;
        } else {
            $name = $element;
            $attributes = array();
        }

        if ( !empty( $result ) ) {
            $result .= ',';
        }

        $result .= $name;

        if ( !empty( $attributes ) ) {
            $result .= '[' . implode('|', $attributes) . ']';
        }

    }

    $settings['extended_valid_elements'] = $result;
    if ( !isset($settings['valid_children'] ) ) {
        $settings['valid_children'] = '';
    }
    $settings['valid_children'] .= '+body[meta],+div[meta],+body[link],+div[link]';

    return $settings;
}

add_filter( 'tiny_mce_before_init', 'tsm_tinymce_init',1,99 );


function allow_itemscope_and_itemprop($allowed, $context) {
    $allowed['div']['itemscope'] = true;
    $allowed['div']['itemtype'] = true;
    $allowed['div']['itemprop'] = true;
    return $allowed;
}
add_filter('wp_kses_allowed_html', 'allow_itemscope_and_itemprop', 10, 2);