Storing PHP Arrays in Wordpress User Meta Database

Question

This should be easy for a PHP expert. I am having trouble storing and pulling arrays in Wordpress through the update_user_meta function.

So I have an associative array built like so:

Array
(
    [film_genres] => Array
        (
            [action] => 50
            [comedy] => 50
            [crime] => 50
            [documentary] => 50
            [drama] => 50
            [family] => 50
            [horror] => 50
            [romantic] => 50
            [sci-fi] => 50
            [thriller] => 50
        )

    [film_types] => Array
        (
            [blockbuster] => 0
            [independent] => 0
        )

    [film_eras] => Array
        (
            [1920s_1940s] => 0
            [1950s_1960s] => 0
            [1970s_1980s] => 0
            [1990s_2000s] => 0
            [post_2010] => 0
            [pre_1920s] => 0
        )

    [last_updated] => 2011-10-12 21:21:28
)

But when I go to update this data in the user meta table via:

update_user_meta( $user_id, $meta_key, $meta_value, $prev_value )

The data gets put in the db properly, but when i call the data back and print the new array to screen, it has a nested array key of [0] within the array, like this:

Array
(
    [0] => Array
        (
            [film_genres] => Array
                (
                    [action] => 50
                    [comedy] => 50
                    [crime] => 50
                    [documentary] => 50
                    [drama] => 50
                    [family] => 50
                    [horror] => 50
                    [romantic] => 50
                    [sci-fi] => 50
                    [thriller] => 50
                )

            [film_types] => Array
                (
                    [blockbuster] => 0
                    [independent] => 0
                )

            [film_eras] => Array
                (
                    [1920s_1940s] => 0
                    [1950s_1960s] => 0
                    [1970s_1980s] => 0
                    [1990s_2000s] => 0
                    [post_2010] => 0
                    [pre_1920s] => 0
                )

            [last_updated] => 2011-10-12 21:21:28
        )

)

How can I get it to store the array exactly like my first array? I am pulling the meta value array via the WP command:

$wp_user_film_prefs_arr = get_user_meta( $wp_user_id, $wp_user_film_prefs_key_label, false );

Is there something I'm doing wrong? Thanks in advance!!!

Solution

You need to set the last parameter from false to true:

$wp_user_film_prefs_arr = get_user_meta( $wp_user_id, $wp_user_film_prefs_key_label, true );

That third parameter is $single:

(boolean) (optional) If true return value of meta data field, if false return an array.

Default: false

That might sound contra-productive in your eyes, but the meta data field can contain multiple values. In your case you don't need that, but the single value. The single value is your array.

See as well: get user meta^Codex

Comments

[chuuke]

Yep, you were right! I initially chose false thinking that it it would then return the array, as in my array of values, but it's retruning an array OF the meta data field. Changed to true to return the value and then stored it as an array with "maybe_unserialize($wp_user_film_prefs_val);" Thanks man!

[James]

WordPress does the serialization for you behind the scenes. @harkra had the correct answer.

[henrywright]

It's hard to get your head around thinking of an array as a single value

[Maciej Krawczyk]

It sure is a poor api design, thanks for your answer!