Combining ACF fields on save

• MikeX3

• July 7, 2019 at 1:23 pm

I am trying to wrap my head around how to use save_post and update_field to combine a field from a post, as well as an option field, into a new field within said post. I don’t know if I need to create the new field first and somehow hide it from the options form, or if I can have it display after save but make it non-editable.. or if acf just makes it in the background without the need for me to make it first (sorry if that doesn’t make sense).

Here’s what I’m trying to do:

In an acf options page, a user will enter their affiliate id: affiliate_id
When creating a post, they will enter a product number: product_id

When the post is saved I want a new field named “link”, within that post, to automatically combine those values so that the following is saved for the new “link” field:

http://www.productsite.com/(product_id)/?ref=(affiliate_id)

Here’s my guess so far as to how this might be done, but it’s really a wild guess trying to string these things together without much php knowledge:

function my_acf_save_post( $post_id ) {
  $affid = (int) get_field('affid');
  $prod = (int) get_field('affiliate_id', 'option');

$link = update_field( "http://www.productsite.com/" . $prod . "/?ref=" . $affid . ""; );

add_action('acf/save_post', 'my_acf_save_post', 15);

• John Huebner

• July 8, 2019 at 9:56 pm

If the field does not need to be editable, use standard WP function to update/get the meta value, no need for an ACF field. https://codex.wordpress.org/Function_Reference/update_post_meta https://developer.wordpress.org/reference/functions/get_post_meta/

however, I would not do this. I would assume that there is something in the post that relates that post to the user. When outputting the post I would look up the get the ID value and append it to the url generated by get_permalink() https://developer.wordpress.org/reference/functions/get_permalink/ rather than create and/or update a field holding a link to the page.