Earlier, I was tying to import a bulk list of links into an ACF repeater. There are several heavy import plugins that will get the job done, but I needed something simpler.
I used CodeWP to generate this code for my use case. When saving a specific post type, it'll check if I've added data to import, and if it's present, add it to the specified repeater. Quick and simple!
Here's how it works.
We have two fields set using ACF for our custom post type. Import links, and the repeater.
If the user saves the post, and there is a common separated, list of links in the import links field, the function will run separating out each link and then adding it as a new repeater role. It will also clear the field.
It uses the acf/save_post action, which fires when saving the submitted $_POST
data.
This function is a quick and simple way to insert large amounts of data into repeaters and it's easily extendable using CodeWP.