PDF icons for GeneratePress

generatepress-mime-icon.php

<?php

/**
 * Add this to your theme functions.php (or preferably in a custom plugin, because a theme
 * update will overwrite the functions.php.
 *
 * You can also try different locations by replacing the 'generate_before_entry_title' with
 * one of the following:
 *
 * - generate_after_entry_title
 * - generate_before_content
 * - generate_after_entry_header
 */
add_action( 'generate_before_entry_title', 'rlv_add_mime_icon' );
function rlv_add_mime_icon() {
  $pdf_icon = 'https://cdn4.iconfinder.com/data/icons/file-extensions-1/64/pdfs-128.png'; // Add the URL to your PDF icon here.
  if ( is_search() ) {
    global $post;
    if ( 'application/pdf' === $post->post_mime_type ) {
      echo "<img class='file-icon pdf' src='$pdf_icon' alt='PDF' />";
    }
  }
}