Passing Variables Between Hooks

In new_meta_for_member() you have $get_meta_value[$req_key] = $data;, but $req_key is not assigned any value. Remember that all variables are local in scope to the function unless explicitly declared global.

Elsewhere, you save the entire $get_meta_value array to user meta. Is that really what you want? Seems to me you’d only want to save the individual keyed value for each user. But then I don’t fully follow your intent.

There may be other issues, I only took a quick look.

First foreach?? I don’t see any foreach in the function new_meta_for_member(). I’m looking at:

function new_meta_for_member($m_key,$id,$data,$status){
global $get_meta_value;
    //The meta key assigned in the admin panel. 
   if($m_key == 'info_member'){
        $get_meta_value[$req_key] = $data;

    }
}

A foreach in some other calling process is of no help. Remember, all PHP variables are local in scope to the function unless declared global. A variable assigned a value in a different function has no bearing in new_meta_for_member().

The values in global $get_meta_value will be saved in user meta alright, but the information passed as $data which you assigned to $get_meta_value[$req_key] will not be saved because the $req_key index is invalid as mentioned above.

You can verify data is saved in the DB by using the phpMyAdmin app and examining the table directly. Newly added data is typically located at the end of the table. Arrays are saved as a serialized string. They’re a little difficult to parse on sight, but if you’re familiar with the array structure and the data it contains you should be able to make sense of it.

While it’s possible to directly edit data via phpMyAdmin, I advise that you do not try to do so unless you’re very sure you know what you’re doing. And even then, make a backup before proceeding. It’s better to look but don’t touch.

I don’t understand the nature of data in $get_meta_value. Maybe it’s OK to save the entire thing in user meta. But instead of incrementally adding meta data in each step of the loop and saving each, collect all data into the array first. Only when all data has been assigned should you save it all to user meta. This entails restructuring your code. TBH, it could stand some restructuring anyway. It seems more convoluted than is necessary.

I think I’ve answered your last question above, but I’m not sure I truly understand your last question. $get_meta_value is global. Its keys are presumably unique, so data saved under different keys will all persist until overwritten or unset. You can assign individual values to each key at different points and all other data in the array will persist. In fact, as a global, before you attempt to start the process on another user (maybe there is no other user, but let’s say there is for the purpose of discussion), you’d need to unset all earlier values, or reinitialize $get_meta_value as an empty array. Otherwise you risk one user getting another’s data.

OTOH, if it were local to a function, once the function returns, all assigned values are gone. Re-entering the function would be as if the variable never existed, it’d have to be reassigned all over again. This behavior can at times be an advantage, other times it’s a curse 🙂

I read it again. I think this is your answer…

Right! Now you see 🙂

Your subsequent questions indicate you’ve encountered the classic dilemma about WP meta data. You’re right, everything in an array under a single key is more efficient in storage. But the array keys in the first scenario still take up space, which you wouldn’t have under the second scenario. The gains are less than it may seem. How many users are you anticipating? Unless you’re anticipating thousands, I doubt it’ll materially affect DB operations. And 30-some rows per users isn’t any worse than we often see in post meta, per post.

The most important consideration in deciding array or multiple keys is how you anticipate using this data to query for users. Using data in serialized arrays as query criteria is very sub-optimal. OTOH, if you will only be fetching this data once the user is known, an array is a great way to save the data.

Furthermore, if you anticipate a huge number of users (thousands) AND you think you’ll be frequently querying for users based on this meta data, the default usermeta table is inefficient to start with. With a lot of users that need to be queried by certain data, that data is best kept in a custom table for the purpose. One that’s organized and indexed for optimal queries.

It may be a hybrid solution would be optimal. Frequently queried data would have their own meta keys (if not their own table). Other user data that’s only needed once the user is known can all be kept in an array under a single meta key.

It looks like the plugin already saves data under separate keys. You’re trying to optimize this by saving it all as an array? An admirable effort, but IMO it’s likely not worth the effort in terms of real world gains.