How can I group posts by months and years?

Question

I have posts under a custom post type which I like to display in a page grouped by Year and Month. In the page template that I create, I managed to separate them by month, but still without grouping at separate levels (they're all same-level, there's just the month name as a break between the groups), like so:

<div class="month"></div>
<div>post title</div>
<div>post title</div>
<div>post title</div>
<div>post title</div>
<div class="month"></div>
<div>post title</div>
<div>post title</div>
<div>post title</div>
<div>post title</div>
<div class="month"></div>
<div>post title</div>
<div>post title</div>
<div>post title</div>
<div>post title</div>

I did that with:

<?php
global $more; $more = false; # some wordpress wtf logic
$posts = get_posts(array(
    'post_type' => 'press',
    'nopaging' => true,
    'orderby' => 'date',
    'order' => 'DSC',
    'posts_per_page'   => 999999,
    ));

$month = null;

foreach($posts as $post): 

    setup_postdata($post); //enables the_title() etc. without specifying a post ID
    $postMonth =  date('FY',strtotime($post->post_date));

    if($month!=$postMonth){
        echo '<div class="month">'.date('F Y',strtotime($post->post_date)).'</div>';        
        $month =$postMonth;
    } ?>

    <div><a href="<?php the_field('url');?>">"<?php the_title();?>"</a></div>

<?php endforeach;?>

What I want to have is something like this:

<div class="year">
    <span>2019</span>
    <div class="month">
        <span>August</span>
            <div>post title</div>
            <div>post title</div>
    </div>
</div>
<div class="year">
    <span>2019</span>
    <div class="month">
        <span>July</span>
            <div>post title</div>
            <div>post title</div>
    </div>
</div>
<div class="year">
    <span>2018</span>
    <div class="month">
        <span>January</span>
            <div>post title</div>
            <div>post title</div>
    </div>
</div>

I tried pretty every solution I could find on StackExchange to no avail. Any ideas?

Answer 1

You can do it like so:

global $post;

$posts = get_posts( array(
    'post_type' => 'press',
    'nopaging'  => true,
    'orderby'   => 'date',
    'order'     => 'DESC', // it's DESC; not DSC
    // There's no use setting posts_per_page when nopaging is enabled.
    // Because posts_per_page will be ignored when nopaging is enabled.
) );

$_year_mon = '';   // previous year-month value
$_has_grp = false; // TRUE if a group was opened
foreach ( $posts as $post ) {
    setup_postdata( $post );

    $time = strtotime( $post->post_date );
    $year = date( 'Y', $time );
    $mon = date( 'F', $time );
    $year_mon = "$year-$mon";

    // Open a new group.
    if ( $year_mon !== $_year_mon ) {
        // Close previous group, if any.
        if ( $_has_grp ) {
            echo '</div><!-- .month -->';
            echo '</div><!-- .year -->';
        }
        $_has_grp = true;

        echo '<div class="year">';
        echo "<span>$year</span>";

        echo '<div class="month">';
        echo "<span>$mon</span>";
    }

    // Display post title.
    if ( $title = get_the_title() ) {
        echo "<div>$title</div>";
    } else {
        echo "<div>#{$post->ID}</div>";
    }

    $_year_mon = $year_mon;
}

// Close the last group, if any.
if ( $_has_grp ) {
    echo '</div><!-- .month -->';
    echo '</div><!-- .year -->';
}

wp_reset_postdata();