Meta Field Block

描述

The plugin allows developers/users to display a meta field as a block on the front end, supporting ACF fields. It can be nested inside a parent block that has postId and postType context, such as Query Block, or used as a stand-alone block.

What is the HTML output of ACF fields?

1. All basic field types that return strings or can cast to strings are supported – The HTML output is from the get_field function.

2. Link type – The HTML output is:

   <a href={url} target={target} rel="noreferrer noopener">{title}</a>
   

   There is no rel attribute if the target is not _blank

3. Image type – The HTML output is from the wp_get_attachment_image function. The image size is from the Preview Size setting.

4. True / False type – The HML output is Yes if the value is true, and No if the value is false. Below is the code snippet to change these text values:

   add_filter( 'meta_field_block_acf_field_true_false_on_text', function ( $on_text, $field, $post_id, $value ) {
     return 'Yep';
   }, 10, 4 );
   
   add_filter( 'meta_field_block_acf_field_true_false_off_text', function ( $off_text, $field, $post_id, $value ) {
     return 'Noop';
   }, 10, 4 );
   

5. Checkbox / Select type – The HTML output is:

   <span class="value-item">{item_value}</span>, <span class="value-item">{item_value}</span>
   

   The item_value can be value or label dependent on the return format of the field. Multiple selected values are separated by ,. Below is the code snippet to change the separator:

   add_filter( 'meta_field_block_acf_field_choice_item_separator', function ( $separator, $value, $field, $post_id ) {
     return ' | ';
   }, 10, 4 );
   

6. Radio button / Button group type – The HTML output is value or label dependent on the return format of the field.

7. Page link type, Post object type – The HTML output for a single-value field is:

   <a class="post-link" href={url} rel="bookmark">{title}</a>
   

   For a multiple-value field is:

   <ul>
     <li><a class="post-link" href={url} rel="bookmark">{title}</a></li>
     <li><a class="post-link" href={url} rel="bookmark">{title}</a></li>
   </ul>
   

8. Relationship type – The HTML output is:

   <ul>
     <li><a class="post-link" href={url} rel="bookmark">{title}</a></li>
     <li><a class="post-link" href={url} rel="bookmark">{title}</a></li>
   </ul>
   

9. Taxonomy type – The HTML output is:

   <ul>
     <li><a class="term-link" href={term_url}>{term_name}</a></li>
     <li><a class="term-link" href={term_url}>{term_name}</a></li>
   </ul>
   

10. User type – The HTML output for a single-value field is:

    <a class="user-link" href={author_url}>{display_name}</a>
    

    For a multiple-value field is:

    <ul>
      <li><a class="user-link" href={author_url}>{display_name}</a></li>
      <li><a class="user-link" href={author_url}>{display_name}</a></li>
    </ul>
    

11. For other complex field types, you can generate a custom HTML output by using the hook:

    apply_filters( 'meta_field_block_get_acf_field', $field_value, $post_id, $field, $raw_value )
    

    Or by using the general hook:

    apply_filters( 'meta_field_block_get_block_content', $content, $attributes, $block, $post_id )
    

    The benefit of the hook meta_field_block_get_acf_field is you can see the changes for both the front end and in the editor.

    Learn more about these hooks in the below Copy & paste section.

Copy & paste snippets

Most of the snippets using the hook meta_field_block_get_block_content only affect the value on the front end, not in the editor.
If your fields are ACF Fields, we recommend using the hook meta_field_block_get_acf_field to change the field content, because with that hook you can change the block content for both the front end and the editor. However, some snippets may not work on the editor because we cannot get the context in the REST API request.

1. How to change the HTML output of the block?
   Using the meta_field_block_get_block_content hook:

   add_filter( 'meta_field_block_get_block_content', function ( $block_content, $attributes, $block, $post_id ) {
     $field_name = $attributes['fieldName'] ?? '';
   
     // Replace `your_field_name` with your unique name.
     if ( 'your_field_name' === $field_name ) {
       $block_content = 'new content';
     }
   
     return $block_content;
   }, 10, 4);
   

   Using the meta_field_block_get_acf_field hook for ACF Fields only:

   add_filter( 'meta_field_block_get_acf_field', function ( $block_content, $post_id, $field, $raw_value ) {
     $field_name = $field['name'] ?? '';
   
     // Replace `your_field_name` with your unique name.
     if ( 'your_field_name' === $field_name ) {
       $block_content = 'new content';
     }
   
     return $block_content;
   }, 10, 4);
   

   This basic snippet is very powerful. You can use it to display any fields from any posts, terms, users or setting fields. Please see the details in the below use cases.

2. How to wrap the block with a link to the post within the Query Loop?
   Using the meta_field_block_get_block_content hook:

   add_filter( 'meta_field_block_get_block_content', function ( $block_content, $attributes, $block, $post_id ) {
     $field_name = $attributes['fieldName'] ?? '';
   
     // Replace `your_field_name` with your unique name.
     if ( 'your_field_name' === $field_name && $block_content !== '' ) {
       $block_content = sprintf('<a href="%1$s">%2$s</a>', get_permalink($post_id), $block_content);
     }
   
     return $block_content;
   }, 10, 4);
   

   Using the meta_field_block_get_acf_field hook for ACF Fields only:

   add_filter( 'meta_field_block_get_acf_field', function ( $block_content, $post_id, $field, $raw_value ) {
     $field_name = $field['name'] ?? '';
   
     // Replace `your_field_name` with your unique name.
     if ( 'your_field_name' === $field_name && $block_content !== '' ) {
       $block_content = sprintf('<a href="%1$s">%2$s</a>', get_permalink($post_id), $block_content);
     }
   
     return $block_content;
   }, 10, 4);
   

   This snippet only works with the block that has only HTML inline tags or an image.

3. How to display an image URL field as an image tag?
   Using the meta_field_block_get_block_content hook:

   add_filter( 'meta_field_block_get_block_content', function ( $block_content, $attributes, $block, $post_id ) {
     $field_name = $attributes['fieldName'] ?? '';
   
     // Replace `your_image_url_field_name` with your unique name.
     if ( 'your_image_url_field_name' === $field_name && wp_http_validate_url($block_content) ) {
       $block_content = sprintf('<img src="%1$s" alt="your_image_url_field_name" />', esc_attr($block_content));
     }
   
     return $block_content;
   }, 10, 4);
   

   Using the meta_field_block_get_acf_field hook for ACF Fields only:

   add_filter( 'meta_field_block_get_acf_field', function ( $block_content, $post_id, $field, $raw_value ) {
     $field_name = $field['name'] ?? '';
   
     // Replace `your_image_url_field_name` with your unique name.
     if ( 'your_image_url_field_name' === $field_name && wp_http_validate_url($block_content) ) {
       $block_content = sprintf('<img src="%1$s" alt="your_image_url_field_name" />', esc_attr($block_content));
     }
   
     return $block_content;
   }, 10, 4);
   

4. How to display an embedded URL (YouTube …) field as an embedded iframe?
   Using the meta_field_block_get_block_content hook:

   add_filter( 'meta_field_block_get_block_content', function ( $block_content, $attributes, $block, $post_id ) {
     $field_name = $attributes['fieldName'] ?? '';
   
     // Replace `your_embedded_url_field_name` with your unique name.
     if ( 'your_embedded_url_field_name' === $field_name && wp_http_validate_url($block_content) ) {
       $block_content = wp_oembed_get( $block_content, array( 'width' => 1024 ) );
     }
   
     return $block_content;
   }, 10, 4);
   

   Using the meta_field_block_get_acf_field hook for ACF Fields only:

   add_filter( 'meta_field_block_get_acf_field', function ( $block_content, $post_id, $field, $raw_value ) {
     $field_name = $field['name'] ?? '';
   
     // Replace `your_embedded_url_field_name` with your unique name.
     if ( 'your_embedded_url_field_name' === $field_name && wp_http_validate_url($block_content) ) {
       $block_content = wp_oembed_get( $block_content, array( 'width' => 1024 ) );
     }
   
     return $block_content;
   }, 10, 4);
   

5. How to display multiple meta fields in a block?
   For example, we need to display the full name of a user from two meta fields first_name and last_name.

   // Create a function to build the full name from two meta fields.
   function yourprefix_get_full_name( $post_id ) {
     $first_name = get_post_meta( $post_id, 'first_name', true );
     $last_name  = get_post_meta( $post_id, 'last_name', true );
   
     // If the meta fields are ACF Fields. The code will be:
     // $first_name = get_field( 'first_name', $post_id );
     // $last_name  = get_field( 'last_name', $post_id );
   
     return trim("$first_name $last_name");
   }
   
   // Register a custom rest field for the full name.
   add_action(
     'rest_api_init',
     function () {
         register_rest_field(
           'post', // Can be an array of post types or a singular value like 'post', 'page', 'product' etc.
           'full_name',
           array(
             'get_callback' => function ( $post_array ) {
               return yourprefix_get_full_name( $post_array['id'] );
             },
             'schema'       => array(
               'type' => 'string',
             ),
           )
         );
     }
   );
   
   // Render the block on the front end.
   add_filter( 'meta_field_block_get_block_content', function ( $block_content, $attributes, $block, $post_id ) {
     $field_name = $attributes['fieldName'] ?? '';
   
     if ( 'full_name' === $field_name ) {
       $block_content = yourprefix_get_full_name( $post_id );
     }
   
     return $block_content;
   }, 10, 4);
   

   Put the above snippet in your theme or plugin, then choose the field type as custom rest field and input the field name as full_name. Please make sure the rest field name is unique.

6. How to display a term meta field?
   For example, we need to display the value of a custom field named cat_attr for the product_cat taxonomy.

   // Create a function to build the value for the field.
   function yourprefix_get_attr_value( $term_id ) {
     $cat_attr_value = get_term_meta( $term_id, 'cat_attr', true );
   
     // If the meta field is an ACF Field. The code will be:
     // $cat_attr_value = get_field( 'cat_attr', 'term_' . $term_id );
   
     return $cat_attr_value;
   }
   
   // Render the block on the front end.
   add_filter( 'meta_field_block_get_block_content', function ( $block_content, $attributes, $block, $post_id ) {
     $field_name = $attributes['fieldName'] ?? '';
   
     // Replace `unique_name_for_cat_attr` with your unique name.
     if ( 'unique_name_for_cat_attr' === $field_name && is_tax( 'product_cat' ) ) {
       $term_id = get_queried_object_id();
       $block_content = yourprefix_get_attr_value( $term_id );
     }
   
     return $block_content;
   }, 10, 4);
   

   Put the above snippet in your theme or plugin, drag the block into the product_cat taxonomy template, then choose the field type as custom rest field or meta and input the field name as unique_name_for_cat_attr. You can customize this snippet to display custom fields for a specific term on any page, or template.

7. How to display a setting field?
   For example, we need to display a setting field named footer_credit on the footer template part of the site.

   // Create a function to build the value for the field.
   function yourprefix_get_footer_credit_text() {
     $footer_credit_text = get_option( 'footer_credit', '' );
   
     // If the field is an ACF Field. The code will be:
     // $footer_credit_text = get_field( 'footer_credit', 'option' );
   
     return $footer_credit_text;
   }
   
   // Render the block on the front end.
   add_filter( 'meta_field_block_get_block_content', function ( $block_content, $attributes, $block, $post_id ) {
     $field_name = $attributes['fieldName'] ?? '';
   
     // Replace `unique_name_for_footer_credit` with your unique name.
     if ( 'unique_name_for_footer_credit' === $field_name ) {
       $block_content = yourprefix_get_footer_credit_text();
     }
   
     return $block_content;
   }, 10, 4);
   

   Using the meta_field_block_get_acf_field hook for ACF Fields only:

   add_filter( 'meta_field_block_get_acf_field', function ( $block_content, $post_id, $field, $raw_value ) {
     $field_name = $field['name'] ?? '';
   
     // Replace `unique_name_for_footer_credit` with your unique name.
     if ( 'unique_name_for_footer_credit' === $field_name ) {
       $block_content = yourprefix_get_footer_credit_text();
     }
   
     return $block_content;
   }, 10, 4);
   

   Put the above snippet in your theme or plugin, drag the block into the template, then choose the field type as custom rest field or meta and input the field name as unique_name_for_footer_credit.

8. How to display custom fields for users on the author template or display custom fields for the logged-in user or any users?

   // Create a function to build the value for the field.
   function yourprefix_get_user_field( $user_id ) {
     $user_field_value = get_user_meta( $user_id, 'your_field_name', true );
   
     // If the meta field is an ACF Field. The code will be:
     // $user_field_value = get_field( 'your_field_name', 'user_' . $user_id );
   
     return $user_field_value;
   }
   
   // Render the block on the front end.
   add_filter( 'meta_field_block_get_block_content', function ( $block_content, $attributes, $block, $post_id ) {
     $field_name = $attributes['fieldName'] ?? '';
   
     // Replace your_field_name with your unique name.
     if ( 'your_field_name' === $field_name && is_author() ) {
       $user_id = get_queried_object_id();
       $block_content = yourprefix_get_user_field( $user_id );
     }
   
     // If you want to display meta fields for logged-in users, then the code would be:
     // if ( 'your_field_name' === $field_name && is_user_logged_in() ) {
     //   $user_id = get_current_user_id();
     //   $block_content = yourprefix_get_user_field( $user_id );
     // }
   
     return $block_content;
   }, 10, 4);
   

   Put the above snippet in your theme or plugin, drag the block into the template, then choose the field type as custom rest field or meta and input the field name as your_field_name.

9. How to use MFB as a placeholder to display any kind of content?

If this plugin is useful for you, please do a quick review and rate it on WordPress.org to help us spread the word. I would very much appreciate it.

Please check out my other plugins if you’re interested:

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The plugin is developed using @wordpress/create-block.