Adding Custom Post Types To get_calendar() And The Calendar Widget

By default or design, the WordPress function `get_calendar()`[^1] does not handle post types other than `post`. I’ve updated it as the standalone function `ucc_get_calendar()` to allow it to accept a `$post_types` array; the included filter function `ucc_get_calendar_filter()` will allow for seamless integration via `functions.php` without requiring additional editing of Theme templates. (Note that the filter will also apply to the Calendar Widget’s output.)

[php]
/* ucc_get_calendar() :: Extends get_calendar() by including custom post types.
* Derived from get_calendar() code in /wp-includes/general-template.php.
*/

function ucc_get_calendar( $post_types = ” , $initial = true , $echo = true ) {
global $wpdb, $m, $monthnum, $year, $wp_locale, $posts;

if ( empty( $post_types ) || !is_array( $post_types ) ) {
$args = array(
‘public’ => true ,
‘_builtin’ => false
);
$output = ‘names’;
$operator = ‘and’;

$post_types = get_post_types( $args , $output , $operator );
$post_types = array_merge( $post_types , array( ‘post’ ) );
} else {
/* Trust but verify. */
$my_post_types = array();
foreach ( $post_types as $post_type ) {
if ( post_type_exists( $post_type ) )
$my_post_types[] = $post_type;
}
$post_types = $my_post_types;
}
$post_types_key = implode( ” , $post_types );
$post_types = "’" . implode( "’ , ‘" , $post_types ) . "’";

$cache = array();
$key = md5( $m . $monthnum . $year . $post_types_key );
if ( $cache = wp_cache_get( ‘get_calendar’ , ‘calendar’ ) ) {
if ( is_array( $cache ) && isset( $cache[$key] ) ) {
remove_filter( ‘get_calendar’ , ‘ucc_get_calendar_filter’ );
$output = apply_filters( ‘get_calendar’, $cache[$key] );
add_filter( ‘get_calendar’ , ‘ucc_get_calendar_filter’ );
if ( $echo ) {
echo $output;
return;
} else {
return $output;
}
}
}

if ( !is_array( $cache ) )
$cache = array();

// Quick check. If we have no posts at all, abort!
if ( !$posts ) {
$sql = "SELECT 1 as test FROM $wpdb->posts WHERE post_type IN ( $post_types ) AND post_status = ‘publish’ LIMIT 1";
$gotsome = $wpdb->get_var( $sql );
if ( !$gotsome ) {
$cache[$key] = ”;
wp_cache_set( ‘get_calendar’ , $cache , ‘calendar’ );
return;
}
}

if ( isset( $_GET[‘w’] ) )
$w = ” . intval( $_GET[‘w’] );

// week_begins = 0 stands for Sunday
$week_begins = intval( get_option( ‘start_of_week’ ) );

// Let’s figure out when we are
if ( !empty( $monthnum ) && !empty( $year ) ) {
$thismonth = ” . zeroise( intval( $monthnum ) , 2 );
$thisyear = ”.intval($year);
} elseif ( !empty( $w ) ) {
// We need to get the month from MySQL
$thisyear = ” . intval( substr( $m , 0 , 4 ) );
$d = ( ( $w – 1 ) * 7 ) + 6; //it seems MySQL’s weeks disagree with PHP’s
$thismonth = $wpdb->get_var( "SELECT DATE_FORMAT( ( DATE_ADD( ‘${thisyear}0101’ , INTERVAL $d DAY ) ) , ‘%m’ ) " );
} elseif ( !empty( $m ) ) {
$thisyear = ” . intval( substr( $m , 0 , 4 ) );
if ( strlen( $m ) < 6 )
$thismonth = ’01’;
else
$thismonth = ” . zeroise( intval( substr( $m , 4 , 2 ) ) , 2 );
} else {
$thisyear = gmdate( ‘Y’ , current_time( ‘timestamp’ ) );
$thismonth = gmdate( ‘m’ , current_time( ‘timestamp’ ) );
}

$unixmonth = mktime( 0 , 0 , 0 , $thismonth , 1 , $thisyear);

// Get the next and previous month and year with at least one post
$previous = $wpdb->get_row( "SELECT DISTINCT MONTH( post_date ) AS month , YEAR( post_date ) AS year
FROM $wpdb->posts
WHERE post_date < ‘$thisyear-$thismonth-01’
AND post_type IN ( $post_types ) AND post_status = ‘publish’
ORDER BY post_date DESC
LIMIT 1" );
$next = $wpdb->get_row( "SELECT DISTINCT MONTH( post_date ) AS month, YEAR( post_date ) AS year
FROM $wpdb->posts
WHERE post_date > ‘$thisyear-$thismonth-01’
AND MONTH( post_date ) != MONTH( ‘$thisyear-$thismonth-01’ )
AND post_type IN ( $post_types ) AND post_status = ‘publish’
ORDER BY post_date ASC
LIMIT 1" );

/* translators: Calendar caption: 1: month name, 2: 4-digit year */
$calendar_caption = _x( ‘%1$s %2$s’ , ‘calendar caption’ );
$calendar_output = ‘<table id="wp-calendar" summary="’ . esc_attr__( ‘Calendar’ ) . ‘">
<caption>’ . sprintf( $calendar_caption , $wp_locale->get_month( $thismonth ) , date( ‘Y’ , $unixmonth ) ) . ‘</caption>
<thead>
<tr>’;

$myweek = array();

for ( $wdcount = 0 ; $wdcount <= 6 ; $wdcount++ ) {
$myweek[] = $wp_locale->get_weekday( ( $wdcount + $week_begins ) % 7 );
}

foreach ( $myweek as $wd ) {
$day_name = ( true == $initial ) ? $wp_locale->get_weekday_initial( $wd ) : $wp_locale->get_weekday_abbrev( $wd );
$wd = esc_attr( $wd );
$calendar_output .= "\n\t\t<th scope=\"col\" title=\"$wd\">$day_name</th>";
}

$calendar_output .= ‘
</tr>
</thead>

<tfoot>
<tr>’;

if ( $previous ) { $calendar_output .= "\n\t\t" . ‘<td colspan="3" id="prev"><a href="’ . get_month_link( $previous->year , $previous->month ) . ‘" title="’ . sprintf( __( ‘View posts for %1$s %2$s’ ) , $wp_locale->get_month( $previous->month ) , date( ‘Y’ , mktime( 0 , 0 , 0 , $previous->month , 1 , $previous->year ) ) ) . ‘">&laquo; ‘ . $wp_locale->get_month_abbrev( $wp_locale->get_month( $previo
us->month ) ) . ‘</a></td>’;
} else {
$calendar_output .= "\n\t\t" . ‘<td colspan="3" id="prev" class="pad">&nbsp;</td>’;
}

$calendar_output .= "\n\t\t" . ‘<td class="pad">&nbsp;</td>’;

if ( $next ) { $calendar_output .= "\n\t\t" . ‘<td colspan="3" id="next"><a href="’ . get_month_link( $next->year , $next->month ) . ‘" title="’ . esc_attr( sprintf( __( ‘View posts for %1$s %2$s’ ) , $wp_locale->get_month( $next->month ) , date( ‘Y’ , mktime( 0 , 0 , 0 , $next->month , 1 , $next->year ) ) ) ) . ‘">’ . $wp_locale->get_month_abbrev( $wp_locale->get_month( $next->month ) ) . ‘ &r
aquo;</a></td>’;
} else {
$calendar_output .= "\n\t\t" . ‘<td colspan="3" id="next" class="pad">&nbsp;</td>’;
}

$calendar_output .= ‘
</tr>
</tfoot>

<tbody>
<tr>’;

// Get days with posts
$dayswithposts = $wpdb->get_results( "SELECT DISTINCT DAYOFMONTH( post_date )
FROM $wpdb->posts WHERE MONTH( post_date ) = ‘$thismonth’
AND YEAR( post_date ) = ‘$thisyear’
AND post_type IN ( $post_types ) AND post_status = ‘publish’
AND post_date < ‘" . current_time( ‘mysql’ ) . ‘\”, ARRAY_N );
if ( $dayswithposts ) {
foreach ( (array) $dayswithposts as $daywith ) {
$daywithpost[] = $daywith[0];
}
} else {
$daywithpost = array();
}

if ( strpos( $_SERVER[‘HTTP_USER_AGENT’] , ‘MSIE’ ) !== false || stripos( $_SERVER[‘HTTP_USER_AGENT’] , ‘camino’ ) !== false || stripos( $_SERVER[‘HTTP_USER_AGENT’] , ‘safari’ ) !== false )
$ak_title_separator = "\n";
else
$ak_title_separator = ‘, ‘;

$ak_titles_for_day = array();
$ak_post_titles = $wpdb->get_results( "SELECT ID, post_title, DAYOFMONTH( post_date ) as dom "
. "FROM $wpdb->posts "
. "WHERE YEAR( post_date ) = ‘$thisyear’ "
. "AND MONTH( post_date ) = ‘$thismonth’ "
. "AND post_date < ‘" . current_time( ‘mysql’ ) . "’ "
. "AND post_type IN ( $post_types ) AND post_status = ‘publish’"
);
if ( $ak_post_titles ) {
foreach ( (array) $ak_post_titles as $ak_post_title ) {

$post_title = esc_attr( apply_filters( ‘the_title’ , $ak_post_title->post_title , $ak_post_title->ID ) );

if ( empty( $ak_titles_for_day[‘day_’ . $ak_post_title->dom] ) )
$ak_titles_for_day[‘day_’.$ak_post_title->dom] = ”;
if ( empty( $ak_titles_for_day["$ak_post_title->dom"] ) ) // first one
$ak_titles_for_day["$ak_post_title->dom"] = $post_title;
else
$ak_titles_for_day["$ak_post_title->dom"] .= $ak_title_separator . $post_title;
}
}

// See how much we should pad in the beginning
$pad = calendar_week_mod( date( ‘w’ , $unixmonth ) – $week_begins );
if ( 0 != $pad )
$calendar_output .= "\n\t\t" . ‘<td colspan="’ . esc_attr( $pad ) . ‘" class="pad">&nbsp;</td>’;

$daysinmonth = intval( date( ‘t’ , $unixmonth ) );
for ( $day = 1 ; $day <= $daysinmonth ; ++$day ) {
if ( isset( $newrow ) && $newrow )
$calendar_output .= "\n\t</tr>\n\t<tr>\n\t\t";
$newrow = false;

if ( $day == gmdate( ‘j’ , current_time( ‘timestamp’ ) ) && $thismonth == gmdate( ‘m’ , current_time( ‘timestamp’ ) ) && $thisyear == gmdate( ‘Y’ , current_time( ‘timestamp’ ) ) )
$calendar_output .= ‘<td id="today">’;
else
$calendar_output .= ‘<td>’;

if ( in_array( $day , $daywithpost ) ) // any posts today?
$calendar_output .= ‘<a href="’ . get_day_link( $thisyear , $thismonth , $day ) . "\" title=\"" . esc_attr( $ak_titles_for_day[$day] ) . "\">$day</a>";
else
$calendar_output .= $day;
$calendar_output .= ‘</td>’;

if ( 6 == calendar_week_mod( date( ‘w’ , mktime( 0 , 0 , 0 , $thismonth , $day , $thisyear ) ) – $week_begins ) )
$newrow = true;
}

$pad = 7 – calendar_week_mod( date( ‘w’ , mktime( 0 , 0 , 0 , $thismonth , $day , $thisyear ) ) – $week_begins );
if ( $pad != 0 && $pad != 7 )
$calendar_output .= "\n\t\t" . ‘<td class="pad" colspan="’ . esc_attr( $pad ) . ‘">&nbsp;</td>’;

$calendar_output .= "\n\t</tr>\n\t</tbody>\n\t</table>";

$cache[$key] = $calendar_output;
wp_cache_set( ‘get_calendar’ , $cache, ‘calendar’ );

remove_filter( ‘get_calendar’ , ‘ucc_get_calendar_filter’ );
$output = apply_filters( ‘get_calendar’, $calendar_output );
add_filter( ‘get_calendar’ , ‘ucc_get_calendar_filter’ );

if ( $echo )
echo $output;
else
return $output;
}

function ucc_get_calendar_filter( $content ) {
$output = ucc_get_calendar( ” , ” , false );
return $output;
}
add_filter( ‘get_calendar’ , ‘ucc_get_calendar_filter’ , 10 , 2 );
[/php]

## References

[^1]: [Function Reference/get calendar](http://codex.wordpress.org/Function_Reference/get_calendar)