custom sortable column

Question

I am trying to create a extra column for year in my timeline custom post. I can create the extra column and I can actually get it sorting and it works correctly but then all my pages then dont seem to work.

this is all of my code i am using to create the column and make it sortable:

// Register the column
add_filter( 'manage_edit-maryg_timeline_columns', 'set_custom_edit_date_columns' );
add_action( 'manage_maryg_timeline_posts_custom_column' , 'custom_date_column', 10, 2 );

function set_custom_edit_date_columns($columns) {
    unset( $columns['date'] );
    $columns['timeline_date'] = __( 'Year', 'your_text_domain' );

    return $columns;
}

//output data for the column
function custom_date_column( $column, $post_id ) {
    switch ( $column ) {
        case 'timeline_date' :
            $year = get_post_meta( $post_id, 'timeline_date', true );

            if ( is_string( $year ) )
                echo $year;
            else
                echo 'Unable to retrieve year';
            break;
    }
}

//make columns sortable
add_filter("manage_edit-maryg_timeline_sortable_columns", 'timeline_sort');
function timeline_sort($columns) {
    // $custom = array(
    //     'timeline_date'   => 'Year'
    // );
    // return wp_parse_args($custom, $columns);
    //or this way
    $columns['timeline_date'] = 'Year';
    return $columns;
}

//make the date column sorted by year by default
add_filter( 'request', 'timeline_column_orderby' );
function timeline_column_orderby( $vars ) {
    if ( !isset( $vars['orderby'] ) || ( isset( $vars['orderby'] ) && 'Year' == $vars['orderby'] ) ) {
        $vars = array_merge( $vars, array(
            'meta_key' => 'timeline_date',
            'orderby' => 'meta_value'
        ) );
    }
    return $vars;
}

the problem code i have narrowed it down to is:

add_filter( 'request', 'timeline_column_orderby' );
function timeline_column_orderby( $vars ) {
    if ( !isset( $vars['orderby'] ) || ( isset( $vars['orderby'] ) && 'Year' == $vars['orderby'] ) ) {
        $vars = array_merge( $vars, array(
            'meta_key' => 'timeline_date',
            'orderby' => 'meta_value'
        ) );
    }
    return $vars;
}

The only thing is i dont understand why my pages not work any more

Thanks in advance

EDIT

I've narrowed it down even further to it being this line of code:

!isset( $vars['orderby'] ) ||

but what im trying to do is sort by this column automatically and if i remove that it doesnt do that

Answer 1

I fixed this issue by changing some of my code.

I changed:

add_filter( 'request', 'timeline_column_orderby' );


function timeline_column_orderby( $vars ) {
          if ( !isset( $vars['orderby'] ) || ( isset( $vars['orderby'] ) && 'Year' == $vars['orderby'] ) ) {
            $vars = array_merge( $vars, array(
                'meta_key' => 'timeline_date',


                  'orderby' => 'meta_value'
                ) );
            }
            return $vars;
 }

to:

add_action( 'load-edit.php', 'sort_year_load' );

function sort_year_load() {
    add_filter( 'request', 'sort_year' );
}

//make the date column sortable by year
function sort_year( $vars ) {

    /* Check if we're viewing the 'maryg_timeline' post type. */
    if ( isset( $vars['post_type'] ) && 'maryg_timeline' == $vars['post_type'] ) {

        /* Check if 'orderby' is set to 'year'. */
        if ( isset( $vars['orderby'] ) && 'Year' == $vars['orderby'] ) {

            /* Merge the query vars with our custom variables. */
            $vars = array_merge(
                $vars,
                array(
                    'meta_key' => 'timeline_date',
                    'orderby' => 'meta_value_num'
                )
            );
        }
    }

    return $vars;
}

Which told WordPress how to sort the table when I click on the clickable table header.

What I am doing is only run my customization on the edit.php page in the admin.

I then check if we're viewing the correct custom post and also if it is set to year. Then I just order it by the meta_key.

My main issue I had was ordering the table on load. I fixed that with this code:

function set_year_post_type_admin_order($wp_query) {
    if (is_admin()) {
        $post_type = $wp_query->query['post_type'];

        if ( $post_type == 'maryg_timeline') {
            $wp_query->set('meta_key', 'timeline_date');
            $wp_query->set('orderby', 'meta_value_num');
            $wp_query->set('order', 'DESC');
        }
    }
}

add_filter ( 'pre_get_posts', 'set_year_post_type_admin_order' );

Which checks if your an admin and the post type and then sets the query to the values I set.

Hope this might help someone else if they come across it