Why do_shortcode is not executing the shortcode in data-* html attributes?

Question

This is on Vanilla installation. I've made a shortcode:-

/**
 * Creates a shortcode for shortcode_use_here
 * @author Omar Tariq <[email protected]>
 */
function callback_banana_abc( $args ){
    /* Don't echo! Always return */

    return 'yay!'; 
}
add_shortcode( 'banana_abc', 'callback_banana_abc' );

And I've made a template that looks like this:-

<?php
/*
 * Template Name: Test Template
 * Description: Hello world.
 */


$str = '<a href="#" title="[banana_abc]" data-abc="[banana_abc]">[banana_abc]</a>';
echo do_shortcode($str);

The output is:-

<a href="#" title="yay!" data-abc="[banana_abc]">yay!</a>

This is only for data-* attributes. It works fine when used in title attribute.

Answer 1

do_shortcodes_in_html_tags() runs attributes through wp_kses_one_attr() which checks them against wp_kses_allowed_html( 'post' ) which by default only accepts standard non-data attributes, so you'd have to add your attribute:

add_filter( 'wp_kses_allowed_html', function ( $allowedposttags, $context ) {
    if ( $context == 'post' ) {
        $allowedposttags['a']['data-abc'] = 1;
    }
    return $allowedposttags;
}, 10, 2 );

Answer 2

I cannot reproduce your problem but the way you are using the shortcode to construct small pieces of that string is making me crazy. Try this, and maybe it will work around your problem as well:

function callback_banana_abc( $args ){
  $atts = shortcode_atts( 
    array(
      'title' => 'yay!',
      'data' => 'yay!',
      'linktext' => 'yay!'
    ), 
    $args
  );
  $str = '<a href="#" title="'.$atts['title'].'" data-abc="'.$atts['data'].'">'.$atts['linktext'].'</a>';
  return $str; 
}
add_shortcode( 'banana_abc', 'callback_banana_abc' );

$str = '[banana_abc]';
echo do_shortcode($str);

$str = '[banana_abc title="ba" data="na" linktext="na"]';
echo do_shortcode($str);