[Plugin: Posts 2 Posts] How To Add Info to Connection

I’m just getting a chance to look through this now. Do we not declare whether or not the connection is reciprocal anymore?

Sorry, my bad, just found it in the ui.php.

Multiple connections to the same post:
Here is a potential situation I might be facing. What if I want to have multiple connections to the same post? In my case, it might be a sponsored player. Maybe someone was sponsored by Nike from 2001-2004, by Adidas from 2005-2009, and in 2010 switched back to Nike again. That should be possible now with the table setup, correct?

No, I didn’t like how data was duplicated. You can register a metabox with reversed parameters if you want to be able to edit connections from both sides.

So assuming that you register the reverse metabox, will it show connections that were made from the other direction?

Multiple connections to the same post: Yes, it is possible, as long as the metadata is different.

The UI currently doesn’t allow you to add multiple connections to the same post.

Hooks
I like the metabox idea, but I was also thinking about potentially adding some hooks into the default P2P_Box_Multiple. Basically, I think most users would just want to be able to hook into the loop where I did, since they will be saving data for each connection. That would keep the majority of people from having to copy a whole extra class out and would make upgrades significantly easier in the future.

I’m running into some problems with my metabox. I’m trying to save my metadata. I replaced your p2p_connect with this loop.

foreach ( array_diff( $new_connections, $old_connections ) as $nc ) {
	$start_date = $_POST[ 'start_date_' . $nc ];
	$end_date = $_POST[ 'end_date_' . $nc ];
	$data = array( "start_date" => $start_date, "end_date" => $end_date );
	p2p_connect( $post_a, $nc, $data );
}

If I run the code above, the metadata can only be inserted when the connection is initially made, because it won’t run the connect code afterwards.

foreach ( $new_connections as $nc ) {
	$start_date = $_POST[ 'start_date_' . $nc ];
	$end_date = $_POST[ 'end_date_' . $nc ];
	$data = array( "start_date" => $start_date, "end_date" => $end_date );
	p2p_connect( $post_a, $nc, $data );
}

If I run this loop, it connects the post again every time the post is updated. My metadata is inserted correctly, but with a new p2p_id each time the update is called.

Once I disconnect the posts, it deletes ALL of the metadata. If there are multiple connections, it should only delete the metadata for that specific connection.

Maybe I’m missing something in the API, but it seems to me that the p2p_id field needs to be added to the metabox that I can use as a variable. That will solve two problems.
1) That will be necessary in order for the UI to be able to have multiple connections to the same post.
2) I can update the post meta directly, so that it can be changed after the connection is originally made.

Hook Implementation
I think hooks would be the best way to deal with this, by hiding core functionality and making P2P much more accessible to the average developer. I think that you could get by with making three hooks available.
1) box: Insert an action hook inside the existing loop per displayed connection. You can insert form fields here or a link to an AJAX form or something if you have more intense connection details.
2) save: Have a save loop similar to what I have proposed here, with a filter hook that lets you edit the $data parameter based on a p2p_id variable.
3) load: I haven’t look much at this, but you’d need a similar hook to the save function in here to let you display your data.

Could you provide an example for how to store a single piece of metadata per connection?