Post Metadata

To add a meta (stored as a WordPress post meta, here a meta called pdf) to your post data (in a variable called pdf_url):

// In a PHP file created under your theme's 'php' folder
function add_meta_to_my_app_posts ( $post_data, $post, $component ) {

    //Standard WordPress post meta:
    $post_data['pdf_url'] = get_post_meta( $post->ID, 'pdf', true );

    //Advanced Custom field meta example:
    $post_data['my_acf_meta'] = get_field( 'my_acf_meta' ); //Post ID not necessary here
    return $post_data ;


add_filter( 'wpak_post_data', 'add_meta_to_my_app_posts', 10, 3);

Then, on app side, to display your post meta in your template:

<!-- In single.html or archive.html template -->
<a href="<%= post.my_pdf %>">Download the pdf for <%= post.title %></a>

<!-- If your "my_acf_meta" is an array -->
      <% _.each( post.my_acf_meta, function( item ) { %>
            <li><%= item %></li>
      <% } ); %>

Post Featured Image Sizes

To add a different image size (like thumbnail) to your post data (in a variable called archive_img):

// In a PHP file created under your theme's 'php' folder
function add_thumbnail_size( $post_data, $post, $component ) {
    $post_featured_img_id = get_post_thumbnail_id( $post->ID );
    $post_data['archive_img'] = ''; // Empty default value to be consistent with WP-AppKit 'thumbnail' data

	if ( !empty( $post_featured_img_id ) ) {
		$featured_img_src = wp_get_attachment_image_src( $post_featured_img_id, 'thumbnail' );
		if( !empty( $featured_img_src ) ) {
            $post_data['archive_img'] = array(
                'src' => $featured_img_src[0],
                'width' => $featured_img_src[1],
                'height' => $featured_img_src[2],

    return $post_data;

add_filter( 'wpak_post_data', 'add_thumbnail_size', 10, 3 );

Then you can use this new image format in your archive.html app template: replace post.thumbnail.src by post.archive_img.src.

Taxonomy Terms

To add the terms of a given taxonomy (my_taxonomy) to your post data (in a variable called my_terms):

// In a PHP file created under your theme's 'php' folder
function add_terms_to_my_app_posts ( $post_data, $post, $component ) {
	// Get the post terms
	$terms = wp_get_post_terms( $post->ID, 'my_taxonomy' );
	// Filter app data (it's better not to include
	// every useless WordPress data into the webservice as this will overload it)
	$terms_in_app = array();
	foreach( $terms as $term ) {
		$terms_in_app[] = array( 'slug' => $term->slug, 'name' => $term->name ); // Put here only the data you need
	$post_data['my_terms'] = $terms_in_app;
	return $post_data; // Return the modified $post_data

add_filter( 'wpak_post_data', 'add_terms_to_my_app_posts', 10, 3 );


To add post comments to your post data instead of retrieving them dynamically (in a variable called comments):

// In a PHP file created under your theme's 'php' folder
function add_comments_to_post( $post_data, $post ) {
        $post_data['comments'] = my_get_post_comments( $post->ID );
        return $post_data;

add_filter( 'wpak_post_data', 'add_comments_to_post', 10, 2 );

function my_get_post_comments( $post_id, $offset = 0 ) {
	$query_args = array(
		'post_id' => $post_id,
		'status' => 'approve',
		'number' => 10, // Here I include only 10 comments
		'offset' => $offset

	return get_comments( $query_args );

To Know More

Published by Lionel on January 5, 2017

Web Developer for an insurance company, WordPress since 2009, aware about front-end performance and curious about (almost) anything


  1. Hello,

    Thank you for these amazing tutorials.

    I have a question, I would like to have all the thumbnail images of the same size in the archive.html, that is 370x210px.

    Can you give me a help please.

    Thank you,

    • Hi,
      If this custom 370x210px size is already an image size defined in you WordPress configuration (by your theme or a plugin) you can replace ‘thumbnail’ by this custom image size name in the above code for “Post Featured Image Sizes”.
      If this custom size is not defined yet you’ll have to add it using the add_image_size() function in your site theme (not app theme), then use the name of this image size in the above code to send it to your app.


Leave a Reply

Your email address will not be published. Required fields are marked *

Having questions?

FAQ | Tutorials | Documentation


Contact Us