Post Object at random

• rhand

• November 15, 2021 at 1:25 am

We have added an advanced custom fields block to load a post object on the home page with the latest custom post type post. This setup allows us to choose a post to display.

"fields": [
  {
      "key": "field_xxxxxx",
      "label": "Label",
      "name": "motd",
      "type": "post_object",
      "instructions": "",
      "required": 0,
      "conditional_logic": 0,
      "wrapper": {
          "width": "",
          "class": "",
          "id": ""
      },
      "post_type": [
          "label"
      ],
      "taxonomy": "",
      "allow_null": 1,
      "multiple": 0,
      "return_format": "object",
      "ui": 1
  }

What we would like to have is the option to load on of the latest x posts at random.

I looked at https://support.advancedcustomfields.com/forums/topic/using-acf-to-create-randomized-ad-block/ and array_rand seems to be useful to load at random from an array of posts.

But how would we do that with the post object choice?

• John Huebner

• November 15, 2021 at 4:36 pm

Your post object field only allows 1 selection. There wouldn’t be anything to use array_rand() on. Your post object field would need to allow multiple values which would return an array of post objects instead on just 1.

• rhand

• November 15, 2021 at 7:43 pm

I guess I can better use a repeater field as well then. One to basically load post slides using array_rand() I do not need a radio select box like in the example.

I would need to use a loop and load a post at random. A basic repeater field example in the ACF Repeater Field tutorial shows how to load a sub field value from a random row of a Repeater field:

<?php
$rows = get_field('repeater_field_name' );
if( $rows ) {
    $index = array_rand( $rows );
    $rand_row = $rows[ $index ];
    $rand_row_title = $rand_row['title'];
    // Do something...
}

This loop is close to what I need, but I would need to “just” load a random post from a taxonomy from the last 3-4 months.

Perhaps I just need an ACF block, in it do a new WP_Query to load custom post type at random from a date range. Will need to think about this more.

• rhand

• November 23, 2021 at 3:31 am

@hube2 I got somewhat further:

<?php

$motd = get_field('motd');

?>

<div id="<?php echo esc_attr($id); ?>" class="<?php echo esc_attr($className); ?>">

<?php
$molecule_month = get_the_terms($motd->ID , 'molecules_of_the_month' );
$month = array_pop($molecule_month);
$molecule_link = get_term_link( $month->term_id, 'molecules_of_the_month' );

// Set the post type here, and sort them randomly
// molecule of the month presented as random molecule of the day.
$args = array(
    'post_type' => 'molecule',
    'posts_per_page'=> 1, 
		'post_category' => 'molecule_of_the_month',
    'order_by' => 'rand',
);
// Initiate a custom query
	
$cpt_query = new WP_Query($args);
	
// If the query has any post, start the loop
if($cpt_query->have_posts()){
    while($cpt_query->have_posts()){
        // Output a link and a thumbnail of the post
        $cpt_query->the_post(); ?>
        <div class="random-post">
					<div class="motd-img">
						<a href="<?php echo $molecule_link ?>">
								<?php echo get_the_post_thumbnail( $motd->ID, 'full');?>"/>
						</a>
					</div>
            <a href="<?php the_permalink();?>"><?php the_title();?></a>
        </div><?php
    }
} ?>

</div>

But got this error

: Uncaught TypeError: array_pop(): Argument #1 ($array) must be of type array, bool given in /Users/jasper/code/site/wp-content/themes/theme/blocks/random-molecule/block.php:30

Why would ID be null? It refers to $month = array_pop($molecule_month); and the field has been set before that line. And we do have molecules of the day(based on month) and molecules of the month.

• rhand

• November 23, 2021 at 3:52 am

I think I cannot call $motd cause it is an ACF block with a post object and another ACF block at that. An existing one where you can select a post. I am working on loading a random one… Might need to create another ACF Block Field Group.

• John Huebner

• November 25, 2021 at 9:54 am

Sorry, don’t know anything to help with the second question.

As for the first

$molecule_month = get_the_terms($motd->ID , 'molecules_of_the_month' );

You need to check the returned value to make sure that it is not empty, that it is not a WP error and that it is an array.

• rhand

• November 27, 2021 at 1:07 am

Seems the variable motd does not load anything so second check fails as well.

<?php
// new acf block field to be added
$motd = get_field('motd');
var_dump($motd); // NULL
$molecule_month = get_the_terms($motd->ID , 'molecules_of_the_month' ); 
var_dump($molecule_month); // warning trying to read property ID on NULL

so results show

NULL
Warning: Attempt to read property “ID” on null in /Users/jasper/code/site/wp-content/themes/theme/blocks/random-molecule/block.php on line 24
bool(false)

And that gets me back to issue with ACF block. I have the base on just loading a molecule on selection and a new one

<?php
acf_register_block_type( array(
  'name'			=> 'molecule-of-the-day',
  'title'			=> __( 'Molecule of the day', 'theme' ),
  'render_template'	=> 'blocks/molecule-of-the-day/block.php',
  'category'		=> 'theme',
  'icon'			=> 'image-filter',
  'mode'			=> 'auto',
  'keywords'		=> array( 'molecule' )
  ));
  acf_register_block_type( array(
  'name'			=> 'random-molecule',
  'title'			=> __( 'Random Molecule', 'theme' ),
  'render_template'	=> 'blocks/random-molecule/block.php',
  'category'		=> 'theme',
  'icon'			=> 'image-filter',
  'mode'			=> 'auto',
  'keywords'		=> array( 'molecule' )
  ));

In the first block $motd = get_field('motd'); works just fine. In my new one under construction it does not. Why is that? Am I doing something now I should not or that is not possible? Just do not understand this.

• rhand

• November 27, 2021 at 1:17 am

Needed to add another location for ACF Block. Loads now. Just still need to select post from selectbox. Need to have one loaded at random instead. Will check some more.

• rhand

• December 7, 2021 at 10:53 pm

As I stated I now have an option to pick a molecule of the day. But I want one at random to load. In ACF we have a motd block with Field Type post object. This seems to create a setup where you can choose an item from the existing ones for the post object or search for one.

How can we load a post at random using an ACF Block from the editor with a Gutenberg Block?

current code:

<?php
// ACF updated to work with new block
$motd = get_field('motd');
var_dump($motd); // NULL
$molecule_month = get_the_terms($motd->ID , 'molecules_of_the_month' ); 
var_dump($molecule_month); // warning trying to read property ID on NULL

?>

<div id="<?php echo esc_attr($id); ?>" class="<?php echo esc_attr($className); ?>">

<?php
// $molecule_month = get_the_terms($motd->ID , 'molecules_of_the_month' );
// $month = array_pop($molecule_month);
// $molecule_link = get_term_link( $month->term_id, 'molecules_of_the_month' );

// Set the post type here, and sort them randomly
// molecule of the month presented as random molecule of the day.
$args = array(
    'post_type' => 'molecule',
    'posts_per_page'=> 1, 
		'post_category' => 'molecule_of_the_month',
    'order_by' => 'rand',
);
// Initiate a custom query
	
$cpt_query = new WP_Query($args);
	
// If the query has any post, start the loop
if($cpt_query->have_posts()){
    while($cpt_query->have_posts()){
        // Output a link and a thumbnail of the post
        $cpt_query->the_post(); ?>
        <div class="random-post">
					<div class="motd-img">
						<a href="<?php echo $molecule_link ?>">
								<?php echo get_the_post_thumbnail( 'full');?>"/>
						</a>
					</div>
					<div class="motd-content">
						<h2 class="is-style-highlight">Molecule of the day</h2>
						<h3 class="motd-name">
							<a href="<?php // echo $molecule_link ?>">
							<?php // echo esc_html( $title ); ?><?php // if($month){ ?> - <?php //echo $month->name; } ?>
							</a>
						</h3>
						<a href="<?php the_permalink();?>"><?php the_title();?></a>
					</div>
        </div>
				<?php
    }
} ?>

• rhand

• December 8, 2021 at 12:43 am

Might just need to use a shortcode to be added to a block

<?php
function imwz_rand_posts() { 
 
$args = array(
    'post_type' => 'molecule',
    'orderby'   => 'rand',
    'posts_per_page' => 1, 
    );
 
$the_query = new WP_Query( $args );
 
if ( $the_query->have_posts() ) {
 
$string .= '<ul>';
    while ( $the_query->have_posts() ) {
        $the_query->the_post();
        $string .= '<li><a href="'. get_permalink() .'">'. get_the_title() .'</a></li>';
    }
    $string .= '</ul>';
    /* Restore original Post Data */
    wp_reset_postdata();
} else {
 
$string .= 'no posts found';
}
 
return $string; 
} 
 
add_shortcode('imwz-random-posts','imwz_rand_posts');
add_filter('widget_text', 'do_shortcode');

See https://www.wpbeginner.com/wp-tutorials/how-to-display-random-posts-in-wordpress/

• rhand

• December 8, 2021 at 1:32 am

Only using

<php?
function imwz_rand_posts() { 
 
$args = array(
    'post_type' => 'molecule',
    'orderby'   => 'rand',
    'posts_per_page' => 1, 
    );
 
$the_query = new WP_Query( $args );
$string = ''; 
if ( $the_query->have_posts() ) {

$string .= '<div>';
    while ( $the_query->have_posts() ) {
        $the_query->the_post();
        $string .= '<h3><a href="'. get_permalink() .'">'. get_the_title() .'</a></h3>';
				$string .= '<p>' . the_excerpt() . '</p>';
    }
    $string .= '</div>';
    /* Restore original Post Data */
    wp_reset_postdata();
} else {
 
$string .= 'no posts found';
}
 
return $string; 
} 

// [imwz-random-posts] shortcode
add_shortcode('imwz-random-posts','imwz_rand_posts');
add_filter('widget_text', 'do_shortcode');

the paragraph part loads above all other data/blocks and not below the title inside the same shortcode block. Any ideas why?

• rhand

• December 8, 2021 at 3:02 am

Needed get_the_excerpt and not output it with the_excerpt Was helped out at https://wordpress.org/support/topic/shortcode-excerpt-loaded-before-all-other-content/#new-topic-0