我有一个扩展现有（原始）插件的功能插件。（之前我只是在分叉，但在更新了原来的插件之后，很明显这不是一个好的做法。）我保存了分叉时使用的代码片段，并希望将它们添加到原始插件中。

我在原始插件中找到了一个钩子：

<?php do_action( \'es_wishlist_add_button\', get_the_ID() ); ?>

我想输入以下代码：

<?php if ( $es_settings->share_facebook ) : ?>
        <a class="a2a_button_facebook" href="https://www.addtoany.com/add_to/facebook?linkurl=<?php the_permalink(); ?>"><i class="fa fa-facebook" aria-hidden="true"></i></a>
    <?php endif; ?>
    <?php if ( $es_settings->share_twitter ) : ?>
        <a class="a2a_button_twitter" href="https://www.addtoany.com/add_to/twitter?linkurl=<?php the_permalink(); ?>"><i class="fa fa-twitter" aria-hidden="true"></i></a>
    <?php endif; ?>
    <?php if ( $es_settings->share_google_plus ) : ?>
        <a class="a2a_button_google_plus" href="https://www.addtoany.com/add_to/facebook?linkurl=<?php the_permalink(); ?>"><i class="fa fa-google-plus" aria-hidden="true"></i></a>
    <?php endif; ?><?php if ( $es_settings->share_linkedin ) : ?>
        <a class="a2a_button_linkedin" href="https://www.addtoany.com/add_to/facebook?linkedin=<?php the_permalink(); ?>"><i class="fa fa-linkedin" aria-hidden="true"></i></a>
    <?php endif; ?>
    <?php if ( $es_settings->use_pdf ) : ?>
        <a href="<?php echo add_query_arg( "es-pdf", get_the_ID(), get_the_permalink() ); ?>" target="_blank"><i class="fa fa-file-pdf-o" aria-hidden="true"></i></a>
    <?php endif; ?>

我在函数插件的函数中使用它。php：

function epf_extra_buttons() {
    echo \'<?php if ( $es_settings->share_facebook ) : ?>
        <a class="a2a_button_facebook" href="https://www.addtoany.com/add_to/facebook?linkurl=<?php the_permalink(); ?>"><i class="fa fa-facebook" aria-hidden="true"></i></a>
    <?php endif; ?>
    <?php if ( $es_settings->share_twitter ) : ?>
        <a class="a2a_button_twitter" href="https://www.addtoany.com/add_to/twitter?linkurl=<?php the_permalink(); ?>"><i class="fa fa-twitter" aria-hidden="true"></i></a>
    <?php endif; ?>
    <?php if ( $es_settings->share_google_plus ) : ?>
        <a class="a2a_button_google_plus" href="https://www.addtoany.com/add_to/facebook?linkurl=<?php the_permalink(); ?>"><i class="fa fa-google-plus" aria-hidden="true"></i></a>
    <?php endif; ?><?php if ( $es_settings->share_linkedin ) : ?>
        <a class="a2a_button_linkedin" href="https://www.addtoany.com/add_to/facebook?linkedin=<?php the_permalink(); ?>"><i class="fa fa-linkedin" aria-hidden="true"></i></a>
    <?php endif; ?>
    <?php if ( $es_settings->use_pdf ) : ?>
        <a href="<?php echo add_query_arg( "es-pdf", get_the_ID(), get_the_permalink() ); ?>" target="_blank"><i class="fa fa-file-pdf-o" aria-hidden="true"></i></a>
    <?php endif; ?>\';
}

add_action(\'es_wishlist_add_button\',\'epf_extra_buttons\');

然而，我没有收到预期的结果。我做错了什么？

function epf_extra_buttons( $post_ID ) {
    // TODO: where does $es_settings come from?

    $encoded_permalink = urlencode(get_the_permalink());
    if ( $es_settings->share_facebook ) {
        echo \'<a class="a2a_button_facebook" href="https://www.addtoany.com/add_to/facebook?linkurl=\' . $encoded_permalink . \'"><i class="fa fa-facebook" aria-hidden="true"></i></a>\';
    }
    if ( $es_settings->share_twitter ) {
        echo \'<a class="a2a_button_twitter" href="https://www.addtoany.com/add_to/twitter?linkurl=\' . $encoded_permalink . \'"><i class="fa fa-twitter" aria-hidden="true"></i></a>\';
    }
    if ( $es_settings->share_google_plus ) {
        echo \'<a class="a2a_button_google_plus" href="https://www.addtoany.com/add_to/facebook?linkurl=\' . $encoded_permalink . \'"><i class="fa fa-google-plus" aria-hidden="true"></i></a>\';
    }
    if ( $es_settings->share_linkedin ) {
        echo \'<a class="a2a_button_linkedin" href="https://www.addtoany.com/add_to/facebook?linkedin=\' . $encoded_permalink . \'"><i class="fa fa-linkedin" aria-hidden="true"></i></a>\';
    }
    if ( $es_settings->use_pdf ) {
        $pdf_url = add_query_arg( "es-pdf", get_the_ID(), get_the_permalink() );
        echo \'<a href="\' .esc_url( $pdf_url ) . \'" target="_blank"><i class="fa fa-file-pdf-o" aria-hidden="true"></i></a>\';
    }
}

add_action(\'es_wishlist_add_button\',\'epf_extra_buttons\');