WordPress中Alt属性为空

Question

我的代码

<?php echo the_post_thumbnail( 'thumbnail' ); ?>

返回：像这样

<img width="650" height="366" src="https://test.com/wp-content/uploads/2019/02/5c1c7adb0c92110fd79f66aa_1545370331112-650x366.jpg" class="attachment-thumbnail size-thumbnail wp-post-image" alt="" srcset="https://test.com/wp-content/uploads/2019/02/5c1c7adb0c92110fd79f66aa_1545370331112-650x366.jpg 650w, https://test.com/wp-content/uploads/2019/02/5c1c7adb0c92110fd79f66aa_1545370331112-300x169.jpg 300w, https://test.com/wp-content/uploads/2019/02/5c1c7adb0c92110fd79f66aa_1545370331112-768x432.jpg 768w, https://test.com/wp-content/uploads/2019/02/5c1c7adb0c92110fd79f66aa_1545370331112-1024x576.jpg 1024w, https://test.com/wp-content/uploads/2019/02/5c1c7adb0c92110fd79f66aa_1545370331112-255x143.jpg 255w, https://test.com/wp-content/uploads/2019/02/5c1c7adb0c92110fd79f66aa_1545370331112-1110x623.jpg 1110w, https://test.com/wp-content/uploads/2019/02/5c1c7adb0c92110fd79f66aa_1545370331112.jpg 1500w" sizes="(max-width: 650px) 100vw, 650px">

在这里，alt属性值为空。

但是我需要为alt属性填充一些东西来修复SEO错误。

提前谢谢。

Answer 1

在活动主题functions.php中添加以下代码

add_filter('wp_get_attachment_image_attributes', 'change_attachement_image_attributes_add_alttopost', 20, 2);

function change_attachement_image_attributes_add_alttopost( $attr, $attachment ){
    // Get post parent
    $parent = get_post_field( 'post_parent', $attachment);

    // Get post type to check if it's post you can also add to any post type
    $type = get_post_field( 'post_type', $parent);
    if( $type != 'post' ){
        return $attr;
    }

    /// Get title
    $title = get_post_field( 'post_title', $parent);

    $attr['alt'] = $title;
    $attr['title'] = $title;

    return $attr;
}

Answer 2

默认情况下，wordpress将从"Media"模块中获取上传的图像内容。

示例，

​

如果图像源包含alt内容，那么"the_post_thumbnail(‘缩略图’)“将返回DOM中的alt文本。