Using multi-dimensional array with filter

Question

I am trying to pass multi-dimensional array using add_filter. I am able to pass single values like this:

add_filter('example_filter', 'my_example_filter_1' );
function my_example_filter_1( $array ){
    $array[]='tax1';
    return $array;
}
add_filter('example_filter', 'my_example_filter_2' );
function my_example_filter_2( $array ){
    $array[]='tax2';
    return $array;
}
add_filter('example_filter', 'my_example_filter_3' );
function my_example_filter_3( $array ){
    $array[]='tax3';
    return $array;
}

print_r( apply_filters( 'example_filter', array()) );

But if the array is of the following format, I am unable to achieve it.

function wte_fixed_starting_dates_license()
{
    $wp_travel_engine = get_option( 'wp_travel_engine_license' );
    $wte_fixed_departure_license_key = isset( $wp_travel_engine['wte_fixed_departure_dates_license_key'] ) ? esc_attr( $wp_travel_engine['wte_fixed_departure_dates_license_key'] ):'';// setup the updater
    $array = 
    array( 
        'version' => '1.0.0',       // current version number
        'license' => $wte_fixed_departure_license_key,  // license key (used get_option above to retrieve from DB)
        'item_id' => WTE_FIXED_DEPARTURE_ITEM_ID,   // id of this product in EDD
        'author'  => 'WP Travel Engine',  // author of this plugin
        'url'     => home_url()
    );
    return $array;
}
add_filter( 'wp_travel_engine_licenses', 'wte_fixed_starting_dates_license' );

I am passing another array using the same filter like this:

function wte_authorize_net_license($array)
{
    $wp_travel_engine = get_option( 'wp_travel_engine_license' );
    $wte_authorize_net_license_key = isset( $wp_travel_engine['wte_authorize_net_dates_license_key'] ) ? esc_attr( $wp_travel_engine['wte_authorize_net_dates_license_key'] ):'';// setup the updater
    $array = 
    array( 
        'version' => '1.0.0',       // current version number
        'license' => $wte_authorize_net_license_key,    // license key (used get_option above to retrieve from DB)
        'item_id' => WTE_FIXED_DEPARTURE_ITEM_ID,   // id of this product in EDD
        'author'  => 'WP Travel Engine',  // author of this plugin
        'url'     => home_url()
    );
    return $array;
}
add_filter( 'wp_travel_engine_licenses', 'wte_authorize_net_license' );

If I pass multiple arrays like this then I only get the later value in the array like this.

Array ( [version] => 1.0.0 [license] => [item_id] => 79 [author] => WP Travel Engine [url] => http://localhost/wordpress )

There should be two version, two license and other parameters as well when I print the array, right? Or am I missing something?

Any help would be highly appreciable. Thanks!

Answer 1

If you using add_filter you should recieve some params, filter than and return it back. If not you will lose previously defined data.

function wte_fixed_starting_dates_license($array) {

Also see array_merge function.

And your example returning right array. license is empty, but other elements is ok.