Setting Parent Posts from Frontend

• SierraKiloGulf

• February 7, 2021 at 2:02 pm

Hi there, long time lurker… generally tend to get the job done from snippets I find around here, but this has been racking my brain for a good few weeks. How can I set a parent post from the frontend? I am using elementor and acf front end with great success, but we are looking to add hierarchical support for a custom post type called myJournals. We would like to give users the ability to link parent journals but can’t seem to make it work. We have ‘hierarchical’ => true so it is working in the backend, but all of our users including editors will be limited to front-end access only.

We have set a relationship field within ACF called related_journals and have tried numerous things in the functions.php to make it work. Any chance you guys could throw us a bone and point us in the right direction?

Also, how would I go about adding a taxonomy term from a field to the post title upon creation? We would like a pre-fix added onto post title and name but it only returns taxonomy number and not the name

• John Huebner

• February 8, 2021 at 1:18 am

Before I answer the entire question. What is the return value of the taxonomy field set to? Term ID or Object?

• SierraKiloGulf

• February 8, 2021 at 2:24 pm

I have tried with term id and object with the same results. I believe the term id was at least giving me the term number, whereas object didn’t show anything.
We have tried both wp_get_post_terms and get_the_terms with no luck.

• SierraKiloGulf

• February 8, 2021 at 5:20 pm

object is coming back as an array, which we can’t seem to get the name of for some reason. I have tried

	  $term = wp_get_object_terms($post->ID, 'myterm');
	  $first_term = $term[0];
	  $term_name = $first_term->name;
          $new_title = $post_id.'- '.$term_name; 

to to avail. my php is quite limited so I’m sure I am not going about this the right way. post ID shows, but I either get an array, or nothing. The case above results in nothing, but if I set new_title to $term it will say array

• John Huebner

• February 9, 2021 at 12:07 am

To set the parent post from the front end you need a relationship field that is only available on the front end. Set this up to start. Add a post object field that only allows one selection.

Create the following filters for your field in functions.php

// only show field on front of site
// https://www.advancedcustomfields.com/resources/acf-prepare_field/
add_filter('acf/prepare_field/name=YOUR FIELD NAME HERE', 'field_only_on_front');
function field_only_on_front($field) {
  if (is_admin()) {
    return false;
  }
  return $field;
}

// alter the acf query of the post object field to only show top level posts
https://www.advancedcustomfields.com/resources/acf-fields-post_object-query/
add_filter('acf/fields/post_object/query/name=YOUR FIELD NAME HERE', 'only_top_level_posts', 20, 3);
function only_top_level_posts($args, $field, $post_id) {
  $args['post_parent'] = 0;
  return $args;
}

After you do this set up your taxonomy field to return term objects

Once all that is done then then create an acf/save_post filter in functions.php

add_action('acf/save_post', 'update_and_save_journal_post');
function update_and_save_journal_post($post_id) {
  // make sure to only do this on the right post type
  $post_type = get_post_type($post_id);
  if ($post_type != 'YOUR POST TYPE HERE') {
    return;
  }
  // get the post
  $post = get_post($post_id);
  // get the parent, unformatted, ID only
  $parent = get_field('YOUR POST OBJECT FIELD', $post_id, false);
  if ($parent ) {
    $post->post_parent = $parent;
  }
  
  // get the taxonomy field
  $terms = get_field('YOUR TAXONOMY FIELD;, $post_id);
  if (!empty($terms) && !is_wp_error($terms)) {
    $term = terms[0];
    $post->post_title = $term->name.$post->post_title;
  }
  // remove this action so that an infinite loop is not created
  remove_filter('acf/save_post', 'update_and_save_journal_post');
  // update the post
  wp_update_post($post);
  // re-add this filter
  add_action('acf/save_post', 'update_and_save_journal_post');
}

Please note that none of the above code has been tested for syntax errors.