How to Modify Calendar Widget?

Hey there,

It is not a native feature in wordpress. It seems that you’re talking about your plugin. I would be able to assist you if you could tell the plugin name you are using.

Thanks!

Hello,

? I’m actually talking about the Widget called Calendar that comes by default in WordPress and can be added in the Sidebar. It is not an external plugin …

I think I have located the file and the code that needs to be modified, but I do not know what code to insert to get a previous and next link for the year …

I guess the file is as follows:
wp-includes->general-template.php

And the code fragment that would have to be modified I think is this:

/**
* Display calendar with days that have posts as links.
*
* The calendar is cached, which will be retrieved, if it exists. If there are
* no posts for the month, then it will not be displayed.
*
* @since 1.0.0
*
* @global wpdb $wpdb
* @global int $m
* @global int $monthnum
* @global int $year
* @global WP_Locale $wp_locale
* @global array $posts
*
* @param bool $initial Optional, default is true. Use initial calendar names.
* @param bool $echo Optional, default is true. Set to false for return.
* @return string|void String when retrieving.
*/
function get_calendar( $initial = true, $echo = true ) {
global $wpdb, $m, $monthnum, $year, $wp_locale, $posts;

$key = md5( $m . $monthnum . $year );
$cache = wp_cache_get( ‘get_calendar’, ‘calendar’ );

if ( $cache && is_array( $cache ) && isset( $cache[ $key ] ) ) {
/** This filter is documented in wp-includes/general-template.php */
$output = apply_filters( ‘get_calendar’, $cache[ $key ] );

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

return $output;
}

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

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

if ( isset( $_GET[‘w’] ) ) {
$w = (int) $_GET[‘w’];
}
// week_begins = 0 stands for Sunday
$week_begins = (int) get_option( ‘start_of_week’ );
$ts = current_time( ‘timestamp’ );

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

$unixmonth = mktime( 0, 0 , 0, $thismonth, 1, $thisyear );
$last_day = date( ‘t’, $unixmonth );

// Get the next and previous month and year with at least one post
$previous = $wpdb->get_row(“SELECT MONTH(post_date) AS month, YEAR(post_date) AS year
FROM $wpdb->posts
WHERE post_date < ‘$thisyear-$thismonth-01’
AND post_type = ‘post’ AND post_status = ‘publish’
ORDER BY post_date DESC
LIMIT 1”);
$next = $wpdb->get_row(“SELECT MONTH(post_date) AS month, YEAR(post_date) AS year
FROM $wpdb->posts
WHERE post_date > ‘$thisyear-$thismonth-{$last_day} 23:59:59’
AND post_type = ‘post’ AND post_status = ‘publish’
ORDER BY post_date ASC
LIMIT 1”);
// Get the next and previous month and year with at least one post José ángel
$previousyear = $wpdb->get_row(“SELECT MONTH(post_date) AS month, YEAR(post_date) AS year
FROM $wpdb->posts
WHERE post_date < ‘$thisyear-0001-$thismonth’
AND post_type = ‘post’ AND post_status = ‘publish’
ORDER BY post_date DESC
LIMIT 1”);
$nextyear = $wpdb->get_row(“SELECT MONTH(post_date) AS month, YEAR(post_date) AS year
FROM $wpdb->posts
WHERE post_date > ‘$thisyear-$thismonth-{$last_day} 23:59:59’
AND post_type = ‘post’ 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”>
<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 = $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”>year, $previous->month) . ‘” title=”‘ . esc_attr( sprintf(__(‘View posts for %1$s %2$s’), $wp_locale->get_month($previous->month), date(‘Y’, mktime(0, 0 , 0, $previous->month, 1, $previous->year)))) . ‘”>« ‘ . $wp_locale->get_month_abbrev($wp_locale->get_month($previous->month)) . ‘</td>’;
} else {
$calendar_output .= “\n\t\t”.'<td colspan=”3″ id=”prev” class=”pad”> </td>’;
}

$calendar_output .= “\n\t\t”.'<td class=”pad”> </td>’;

if ( $next ) {
$calendar_output .= “\n\t\t”.'<td colspan=”3″ id=”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)) . ‘ »</td>’;
} else {
$calendar_output .= “\n\t\t”.'<td colspan=”3″ id=”next” class=”pad”> </td>’;
}

$calendar_output .= ‘
</tr>

</tfoot>

<tbody>
<tr>’;

$daywithpost = array();

// Get days with posts
$dayswithposts = $wpdb->get_results(“SELECT DISTINCT DAYOFMONTH(post_date)
FROM $wpdb->posts WHERE post_date >= ‘{$thisyear}-{$thismonth}-01 00:00:00’
AND post_type = ‘post’ AND post_status = ‘publish’
AND post_date <= ‘{$thisyear}-{$thismonth}-{$last_day} 23:59:59′”, ARRAY_N);
if ( $dayswithposts ) {
foreach ( (array) $dayswithposts as $daywith ) {
$daywithpost[] = $daywith[0];
}
}

// 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”> </td>’;
}

$newrow = false;
$daysinmonth = (int) 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’, $ts ) &&
$thismonth == gmdate( ‘m’, $ts ) &&
$thisyear == gmdate( ‘Y’, $ts ) ) {
$calendar_output .= ‘<td id=”today”>’;
} else {
$calendar_output .= ‘<td>’;
}

if ( in_array( $day, $daywithpost ) ) {
// any posts today?
$date_format = date( _x( ‘F j, Y’, ‘daily archives date format’ ), strtotime( “{$thisyear}-{$thismonth}-{$day}” ) );
/* translators: Post calendar label. 1: Date */
$label = sprintf( __( ‘Posts published on %s’ ), $date_format );
$calendar_output .= sprintf(
‘%s‘,
get_day_link( $thisyear, $thismonth, $day ),
esc_attr( $label ),
$day
);
} 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 ) .'”> </td>’;
}
$calendar_output .= “\n\t</tr>\n\t</tbody>\n\t</table>”;

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

if ( $echo ) {
/**
* Filters the HTML calendar output.
*
* @since 3.0.0
*
* @param string $calendar_output HTML output of the calendar.
*/
echo apply_filters( ‘get_calendar’, $calendar_output );
return;
}
/** This filter is documented in wp-includes/general-template.php */
return apply_filters( ‘get_calendar’, $calendar_output );
}

/**
* Purge the cached results of get_calendar.
*
* @see get_calendar
* @since 2.1.0
*/
function delete_get_calendar_cache() {
wp_cache_delete( ‘get_calendar’, ‘calendar’ );
}

/**
* Display all of the allowed tags in HTML format with attributes.
*
* This is useful for displaying in the comment area, which elements and
* attributes are supported. As well as any plugins which want to display it.
*
* @since 1.0.1
*
* @global array $allowedtags
*
* @return string HTML allowed tags entity encoded.
*/
function allowed_tags() {
global $allowedtags;
$allowed = ”;
foreach ( (array) $allowedtags as $tag => $attributes ) {
$allowed .= ‘<‘.$tag;
if ( 0 < count($attributes) ) {
foreach ( $attributes as $attribute => $limits ) {
$allowed .= ‘ ‘.$attribute.’=””‘;
}
}
$allowed .= ‘> ‘;
}
return htmlentities( $allowed );
}

/***** Date/Time tags *****/

/**
* Outputs the date in iso8601 format for xml files.
*
* @since 1.0.0
*/
function the_date_xml() {
echo mysql2date( ‘Y-m-d’, get_post()->post_date, false );
}

/**
* Display or Retrieve the date the current post was written (once per date)
*
* Will only output the date if the current post’s date is different from the
* previous one output.
*
* i.e. Only one date listing will show per day worth of posts shown in the loop, even if the
* function is called several times for each post.
*
* HTML output can be filtered with ‘the_date’.
* Date string output can be filtered with ‘get_the_date’.
*
* @since 0.71
*
* @global string|int|bool $currentday
* @global string|int|bool $previousday
*
* @param string $d Optional. PHP date format defaults to the date_format option if not specified.
* @param string $before Optional. Output before the date.
* @param string $after Optional. Output after the date.
* @param bool $echo Optional, default is display. Whether to echo the date or return it.
* @return string|void String if retrieving.
*/
function the_date( $d = ”, $before = ”, $after = ”, $echo = true ) {
global $currentday, $previousday;

if ( is_new_day() ) {
$the_date = $before . get_the_date( $d ) . $after;
$previousday = $currentday;

/**
* Filters the date a post was published for display.
*
* @since 0.71
*
* @param string $the_date The formatted date string.
* @param string $d PHP date format. Defaults to ‘date_format’ option
* if not specified.
* @param string $before HTML output before the date.
* @param string $after HTML output after the date.
*/
$the_date = apply_filters( ‘the_date’, $the_date, $d, $before, $after );

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

/**
* Retrieve the date on which the post was written.
*
* Unlike the_date() this function will always return the date.
* Modify output with the {@see ‘get_the_date’} filter.
*
* @since 3.0.0
*
* @param string $d Optional. PHP date format defaults to the date_format option if not specified.
* @param int|WP_Post $post Optional. Post ID or WP_Post object. Default current post.
* @return false|string Date the current post was written. False on failure.
*/
function get_the_date( $d = ”, $post = null ) {
$post = get_post( $post );

if ( ! $post ) {
return false;
}

if ( ” == $d ) {
$the_date = mysql2date( get_option( ‘date_format’ ), $post->post_date );
} else {
$the_date = mysql2date( $d, $post->post_date );
}

/**
* Filters the date a post was published.
*
* @since 3.0.0
*
* @param string $the_date The formatted date.
* @param string $d PHP date format. Defaults to ‘date_format’ option
* if not specified.
* @param int|WP_Post $post The post object or ID.
*/
return apply_filters( ‘get_the_date’, $the_date, $d, $post );
}

/**
* Display the date on which the post was last modified.
*
* @since 2.1.0
*
* @param string $d Optional. PHP date format defaults to the date_format option if not specified.
* @param string $before Optional. Output before the date.
* @param string $after Optional. Output after the date.
* @param bool $echo Optional, default is display. Whether to echo the date or return it.
* @return string|void String if retrieving.
*/
function the_modified_date( $d = ”, $before = ”, $after = ”, $echo = true ) {
$the_modified_date = $before . get_the_modified_date($d) . $after;

/**
* Filters the date a post was last modified for display.
*
* @since 2.1.0
*
* @param string $the_modified_date The last modified date.
* @param string $d PHP date format. Defaults to ‘date_format’ option
* if not specified.
* @param string $before HTML output before the date.
* @param string $after HTML output after the date.
*/
$the_modified_date = apply_filters( ‘the_modified_date’, $the_modified_date, $d, $before, $after );

if ( $echo )
echo $the_modified_date;
else
return $the_modified_date;

}

/**
* Retrieve the date on which the post was last modified.
*
* @since 2.1.0
* @since 4.6.0 Added the $post parameter.
*
* @param string $d Optional. PHP date format defaults to the date_format option if not specified.
* @param int|WP_Post $post Optional. Post ID or WP_Post object. Default current post.
* @return false|string Date the current post was modified. False on failure.
*/
function get_the_modified_date( $d = ”, $post = null ) {
$post = get_post( $post );

if ( ! $post ) {
// For backward compatibility, failures go through the filter below.
$the_time = false;
} elseif ( empty( $d ) ) {
$the_time = get_post_modified_time( get_option( ‘date_format’ ), false, $post, true );
} else {
$the_time = get_post_modified_time( $d, false, $post, true );
}

/**
* Filters the date a post was last modified.
*
* @since 2.1.0
* @since 4.6.0 Added the $post parameter.
*
* @param string $the_time The formatted date.
* @param string $d PHP date format. Defaults to value specified in
* ‘date_format’ option.
* @param WP_Post $post WP_Post object.
*/
return apply_filters( ‘get_the_modified_date’, $the_time, $d, $post );
}

/**
* Display the time at which the post was written.
*
* @since 0.71
*
* @param string $d Either ‘G’, ‘U’, or php date format.
*/
function the_time( $d = ” ) {
/**
* Filters the time a post was written for display.
*
* @since 0.71
*
* @param string $get_the_time The formatted time.
* @param string $d The time format. Accepts ‘G’, ‘U’,
* or php date format.
*/
echo apply_filters( ‘the_time’, get_the_time( $d ), $d );
}

/**
* Retrieve the time at which the post was written.
*
* @since 1.5.0
*
* @param string $d Optional. Format to use for retrieving the time the post
* was written. Either ‘G’, ‘U’, or php date format defaults
* to the value specified in the time_format option. Default empty.
* @param int|WP_Post $post WP_Post object or ID. Default is global $post object.
* @return string|int|false Formatted date string or Unix timestamp if $id is ‘U’ or ‘G’. False on failure.
*/
function get_the_time( $d = ”, $post = null ) {
$post = get_post($post);

if ( ! $post ) {
return false;
}

if ( ” == $d )
$the_time = get_post_time(get_option(‘time_format’), false, $post, true);
else
$the_time = get_post_time($d, false, $post, true);

/**
* Filters the time a post was written.
*
* @since 1.5.0
*
* @param string $the_time The formatted time.
* @param string $d Format to use for retrieving the time the post was written.
* Accepts ‘G’, ‘U’, or php date format value specified
* in ‘time_format’ option. Default empty.
* @param int|WP_Post $post WP_Post object or ID.
*/
return apply_filters( ‘get_the_time’, $the_time, $d, $post );
}

/**
* Retrieve the time at which the post was written.
*
* @since 2.0.0
*
* @param string $d Optional. Format to use for retrieving the time the post
* was written. Either ‘G’, ‘U’, or php date format. Default ‘U’.
* @param bool $gmt Optional. Whether to retrieve the GMT time. Default false.
* @param int|WP_Post $post WP_Post object or ID. Default is global $post object.
* @param bool $translate Whether to translate the time string. Default false.
* @return string|int|false Formatted date string or Unix timestamp if $id is ‘U’ or ‘G’. False on failure.
*/
function get_post_time( $d = ‘U’, $gmt = false, $post = null, $translate = false ) {
$post = get_post($post);

if ( ! $post ) {
return false;
}

if ( $gmt )
$time = $post->post_date_gmt;
else
$time = $post->post_date;

$time = mysql2date($d, $time, $translate);

/**
* Filters the localized time a post was written.
*
* @since 2.6.0
*
* @param string $time The formatted time.
* @param string $d Format to use for retrieving the time the post was written.
* Accepts ‘G’, ‘U’, or php date format. Default ‘U’.
* @param bool $gmt Whether to retrieve the GMT time. Default false.
*/
return apply_filters( ‘get_post_time’, $time, $d, $gmt );
}

/**
* Display the time at which the post was last modified.
*
* @since 2.0.0
*
* @param string $d Optional Either ‘G’, ‘U’, or php date format defaults to the value specified in the time_format option.
*/
function the_modified_time($d = ”) {
/**
* Filters the localized time a post was last modified, for display.
*
* @since 2.0.0
*
* @param string $get_the_modified_time The formatted time.
* @param string $d The time format. Accepts ‘G’, ‘U’,
* or php date format. Defaults to value
* specified in ‘time_format’ option.
*/
echo apply_filters( ‘the_modified_time’, get_the_modified_time($d), $d );
}

/**
* Retrieve the time at which the post was last modified.
*
* @since 2.0.0
* @since 4.6.0 Added the $post parameter.
*
* @param string $d Optional. Format to use for retrieving the time the post
* was modified. Either ‘G’, ‘U’, or php date format defaults
* to the value specified in the time_format option. Default empty.
* @param int|WP_Post $post Optional. Post ID or WP_Post object. Default current post.
* @return false|string Formatted date string or Unix timestamp. False on failure.
*/
function get_the_modified_time( $d = ”, $post = null ) {
$post = get_post( $post );

if ( ! $post ) {
// For backward compatibility, failures go through the filter below.
$the_time = false;
} elseif ( empty( $d ) ) {
$the_time = get_post_modified_time( get_option( ‘time_format’ ), false, $post, true );
} else {
$the_time = get_post_modified_time( $d, false, $post, true );
}

/**
* Filters the localized time a post was last modified.
*
* @since 2.0.0
* @since 4.6.0 Added the $post parameter.
*
* @param string $the_time The formatted time.
* @param string $d Format to use for retrieving the time the post was
* written. Accepts ‘G’, ‘U’, or php date format. Defaults
* to value specified in ‘time_format’ option.
* @param WP_Post $post WP_Post object.
*/
return apply_filters( ‘get_the_modified_time’, $the_time, $d, $post );
}

/**
* Retrieve the time at which the post was last modified.
*
* @since 2.0.0
*
* @param string $d Optional. Format to use for retrieving the time the post
* was modified. Either ‘G’, ‘U’, or php date format. Default ‘U’.
* @param bool $gmt Optional. Whether to retrieve the GMT time. Default false.
* @param int|WP_Post $post WP_Post object or ID. Default is global $post object.
* @param bool $translate Whether to translate the time string. Default false.
* @return string|int|false Formatted date string or Unix timestamp if $id is ‘U’ or ‘G’. False on failure.
*/
function get_post_modified_time( $d = ‘U’, $gmt = false, $post = null, $translate = false ) {
$post = get_post($post);

if ( ! $post ) {
return false;
}

if ( $gmt )
$time = $post->post_modified_gmt;
else
$time = $post->post_modified;
$time = mysql2date($d, $time, $translate);

/**
* Filters the localized time a post was last modified.
*
* @since 2.8.0
*
* @param string $time The formatted time.
* @param string $d The date format. Accepts ‘G’, ‘U’, or php date format. Default ‘U’.
* @param bool $gmt Whether to return the GMT time. Default false.
*/
return apply_filters( ‘get_post_modified_time’, $time, $d, $gmt );
}

/**
* Display the weekday on which the post was written.
*
* @since 0.71
*
* @global WP_Locale $wp_locale
*/
function the_weekday() {
global $wp_locale;
$the_weekday = $wp_locale->get_weekday( mysql2date( ‘w’, get_post()->post_date, false ) );

/**
* Filters the weekday on which the post was written, for display.
*
* @since 0.71
*
* @param string $the_weekday
*/
echo apply_filters( ‘the_weekday’, $the_weekday );
}

/**
* Display the weekday on which the post was written.
*
* Will only output the weekday if the current post’s weekday is different from
* the previous one output.
*
* @since 0.71
*
* @global WP_Locale $wp_locale
* @global string|int|bool $currentday
* @global string|int|bool $previousweekday
*
* @param string $before Optional Output before the date.
* @param string $after Optional Output after the date.
*/
function the_weekday_date($before=”,$after=”) {
global $wp_locale, $currentday, $previousweekday;
$the_weekday_date = ”;
if ( $currentday != $previousweekday ) {
$the_weekday_date .= $before;
$the_weekday_date .= $wp_locale->get_weekday( mysql2date( ‘w’, get_post()->post_date, false ) );
$the_weekday_date .= $after;
$previousweekday = $currentday;
}

/**
* Filters the localized date on which the post was written, for display.
*
* @since 0.71
*
* @param string $the_weekday_date
* @param string $before The HTML to output before the date.
* @param string $after The HTML to output after the date.
*/
$the_weekday_date = apply_filters( ‘the_weekday_date’, $the_weekday_date, $before, $after );
echo $the_weekday_date;
}

/**