Hi Matt,
Sadly, we don’t have any sort of resources for this, which may make it pretty interesting to try and convert between the two. I imagine both store their content differently, so trying to make sure it maps perfectly is going to be a challenge. The more complex the fields, the more complex the conversion, likely. Simple text fields may be easier.
Main thing I can say is that CMB2 does store its content in the standard wp_postmeta table.
Make a backup and try this first:
https://github.com/Hube2/custom-field-converter
Doesnt work with repeater field.
Thanks for the plug Stagger Lee. It should be possible to convert ACF fields of any kind to standard WP postmeta fields. Although I doubt that it will work if CMB2 stores data in any special ways.
For example, ACF stores multiselect fields as a serialized array and my converter will put these into multiple DB entries, the way WP generally does. It can convert repeater fields, but once again each row becomes multiple entries and you loose the ability to match the values in the same row.
I have built hooks into the plugin that will let you do things that the plugin will not already do and build data to be converted in ways that are more specific and cannot be done generically. I hadn’t actually thought about using to convert to other plugins, my main purpose for creating the plugin was to make it easier to search ACF fields using WP_Query. But I wouldn’t mind input if any bugs are found.
We use standard wp_postmeta table for “post”-like metaboxes. Options table for custom options pages.
