Meta Field Block

描述

This single-block plugin allows you to display a meta field or a custom field as a block on the front end. It supports custom fields for posts, terms, and users. It can be nested inside a parent block that has postId and postType context, such as Query Block, WooCommerce Product Collection, or used as a stand-alone block.

You can display any field whose value can be retrieved by the core API (get_post_meta, get_term_meta, get_user_meta) and is a string or can be converted to a string. To display the field value in the Block Editor, it has to be accessible via the REST API or have the field type set to dynamic.

You can also display custom fields created by the Advanced Custom Fields or Meta Box plugin explicitly. It supports all ACF field types and Meta Box field types whose values are strings or can be converted to strings. Some other ACF complex fields such as Image, Link, Page Link, True False, Checkbox, Select, Radio, Button Group, Taxonomy, User, Post Object and Relationship field types as well as Meta Box fields such as Select, Checkbox, Radio, Image, Video, Taxonomy, User, Post field types are also supported in basic formats.

This plugin also provides developer-friendly hook APIs that allow you to easily customize the output of the block, display complex data type fields, or use the block as a placeholder to display any kind of content with object_id and object_type as context parameters.

An edge case where this block is really helpful is when you need to get the correct post_id in your shortcode when you use it in a Query Loop. In that case, you can set the field type as dynamic and input your shortcode in the field name. The block will display it correctly on both the front end and the editor. Alternatively, if you only want to see the preview of your shortcode in the editor, you can also use this block as a better version of the core/shortcode.

Links

• Website
• How it works
• MFB PRO

What is the HTML output of a custom field?

The HTML output of a custom field on the front end depends on the context of the field. It uses one of these core API functions to get the field value: get_post_meta, get_term_meta, get_user_meta.

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_true_false_on_text', function ( $on_text, $field_name, $field, $post_id, $value ) {
     return 'Yep';
   }, 10, 4 );
   
   add_filter( 'meta_field_block_true_false_off_text', function ( $off_text, $field_name, $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 either value or label, depending 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, $field_name, $field, $post_id, $value ) {
     return ' | ';
   }, 10, 4 );
   

6. Radio button / Button group type – The HTML output can be either value or label, depending 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, $object_type )
    

    Or by using the general hook:

    apply_filters( 'meta_field_block_get_block_content', $content, $attributes, $block, $object_id, $object_type )
    

What is the HTML output of Meta Box fields?

1. Similar to ACF fields, all basic fields that return strings or can cast to strings using the function rwmb_get_value are supported.

   The HTML output of cloneable basic fields is:

   <span class="value-repeater-item">{item_1_value}</span>, <span class="value-repeater-item">{item_2_value}</span>
   

   Use the following hooks to change the tag and the separator:

   apply_filters( 'meta_field_block_mb_clone_field_item_separator', ', ', $field, $post_id, $field_value )
   apply_filters( 'meta_field_block_mb_clone_field_item_tag', 'span', $field, $post_id, $field_value )
   

2. Single image types – The HTML output is from the wp_get_attachment_image function. The image size is from the image_size setting.

3. Image list types (Cloneable Single image, Image, Image advanced, Image upload) – The HTML output is:

   <figure class="image-list">
     <figure class="image-item"><img /></figure>
     <figure class="image-item"><img /></figure>
   </figure>
   

4. Checkbox / Switch type – Similar to ACF True / False type.

5. Multi-choice types (Select, Select advanced, Button group, Autocomplete, Image select, Checkbox list) – The HTML output is:

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

   To display the label instead of the value, use this hook:

   apply_filters( 'meta_field_block_mb_field_choice_item_display_label', false, $field_name, $field, $post_id, $value )
   

   To change the separator, use this hook:

   apply_filters( 'meta_field_block_mb_field_choice_item_separator', ', ', $file_name, $field, $post_id, $value )
   

6. Radio type – The output is the field value by default. To display label or change the separator, use the same hooks as the multi-choice types.

7. Post 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. Taxonomy, Taxonomy advanced type – The HTML output for a single-value field is:

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

   For a multiple-value field 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>
   

9. User type – Similar to ACF User type

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

    <video controls preload="metadata" src={video_src} width={video_width} poster={poster} />
    

    For a multiple-value field is:

    <figure class="video-list">
      <figure class="video-item"><video /></figure>
      <figure class="video-item"><video /></figure>
    </figure>
    

11. To display complex field types or change the output of a field, use the hook meta_field_block_get_mb_field or the general hook meta_field_block_get_block_content.

Copy & paste snippets

When using the meta_field_block_get_block_content hook to customize block content, we recommend selecting dynamic as the field type. This way, both the front end and the editor will show the changes. If you are working with ACF Fields, we suggest using the meta_field_block_get_acf_field hook to modify the field content. Similarly, Meta Box users should use the meta_field_block_get_mb_field hook to modify the content. ACF snippets can also be used with Meta Box fields, but you must use the correct hook name and replace the get_field function with the rwmb_get_value function.

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, $object_type ) {
     $field_name = $attributes['fieldName'] ?? '';
   
     if ( 'your_unique_field_name' === $field_name ) {
       $block_content = 'new content';
     }
   
     return $block_content;
   }, 10, 5);
   

   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, $object_type ) {
     $field_name = $field['name'] ?? '';
   
     if ( 'your_unique_field_name' === $field_name ) {
       $block_content = 'new content';
     }
   
     return $block_content;
   }, 10, 5);
   

   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'] ?? '';
   
     if ( 'your_unique_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'] ?? '';
   
     if ( 'your_unique_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'] ?? '';
   
     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'] ?? '';
   
     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 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.

   add_filter( 'meta_field_block_get_block_content', function ( $block_content, $attributes, $block, $post_id ) {
     $field_name = $attributes['fieldName'] ?? '';
   
     if ( 'full_name' === $field_name ) {
       $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 );
   
       $block_content = trim("$first_name $last_name");
     }
   
     return $block_content;
   }, 10, 4);
   

   Choose the field type as dynamic and input the field name as full_name.

5. 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.

   add_filter( 'meta_field_block_get_block_content', function ( $block_content, $attributes, $block, $post_id ) {
     $field_name = $attributes['fieldName'] ?? '';
   
     // Replace `footer_credit` with your unique name.
     if ( 'footer_credit' === $field_name ) {
       $block_content = get_option( 'footer_credit', '' );
   
       // If the field is an ACF Field. The code will be:
       // $block_content = get_field( 'footer_credit', 'option' );
     }
   
     return $block_content;
   }, 10, 4);
   

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

SAVE YOUR TIME WITH MFB PRO

To display simple data type fields for posts, terms, and users, you only need the free version of MFB. MFB Pro can save you 90% of development time when working with ACF, or Meta Box complex fields. It achieves this by transforming your ACF complex field types into container blocks, which work similarly to core container blocks. This eliminates the need for creating custom blocks or writing custom code for displaying complex fields.
Below is a video tutorial on how to use MFB Pro to build a post template without coding

The main features of MFB PRO are:

• Display settings fields.
• Display ACF advanced layout fields: Group, Repeater, and Flexible content.
• Display ACF Repeater fields in a carousel layout, which is useful for displaying banner sliders.
• Display ACF Relationship and Post Object fields as a Query Loop.
• Display the ACF Image field as a core image block.
• Display the ACF Gallery field as a gallery using grid or masonry layouts or as a carousel of images.
• Display the ACF File field as a video block, an image block, a button block, or a link.
• Display the ACF Link field as a button block.
• Display the ACF URL field as an image block, a button block, or a link.
• Display the ACF Email, and ACF File fields as a button block or a link.
• Display the Meta Box Group field, similar to the ACF Group field.
• Display the Meta Box Cloneable Group field as a repeater block, similar to the ACF Repeater field. Supports row, stack, grid or carousel layouts.
• Display the Meta Box Post field as a Query Loop.
• Display the Meta Box single image fields as an image block.
• Display the Meta Box image list fields as a gallery using grid or masonry layouts or as a carousel of images, similar to the ACF Gallery field.
• Display the Meta Box File single input field as a video block, an image block, or a button.
• Set a single image sub-field (ACF Image or Meta Box Image) as the background image of a group field.
• Display custom fields from a specific post, term or user

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:

• Content Blocks Builder – This plugin turns the Block Editor into a powerful page builder by allowing you to create blocks, variations, and patterns directly in the Block Editor without needing a code editor.
• SVG Block – A block to display SVG images as blocks. Useful for images, icons, dividers, and buttons. It allows you to upload SVG images and load them into the icon library.
• Icon separator – A tiny block just like the core/separator block but with the ability to add an icon.
• Breadcrumb Block – A simple breadcrumb trail block that supports JSON-LD structured data and is compatible with WooCommerce.
• Block Enhancements – Adds practical features to blocks like icons, box shadows, transforms, etc.
• Counting Number Block – A block to display numbers with a counting effect
• Better YouTube Embed Block – A block to solve the performance issue with embedded YouTube videos. It can also embed multiple videos and playlists.

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