if statement in a for each function - php

Question

$args = array( 'numberposts' => '3' );
$recent_posts = wp_get_recent_posts( $args );
foreach( $recent_posts as $recent ){
echo '<a style="color:white;text-decoration:none;" href="'. get_permalink($recent["ID"]) .'">
<article class="post post_home" style="background-image: url('.
function(){
if( has_post_thumbnail() ) {
echo get_the_post_thumbnail_url( $recent["ID"], 'cover' );
} elseif ( has_category( 'positive-morning' ) ) {
echo get_bloginfo('template_directory') . '/img/BG/2-Morning.jpg';
} elseif ( has_category( 'positive-talks' ) ) {
echo get_bloginfo('template_directory') . '/img/BG/2-Talks.jpg'; }
}
.');
background-position : center; background-size :cover;">
<h2>'. $recent["post_title"] .'</h2></article>';
....
}
Hi all,
I'm having trouble to put an if statement because when I add the if statement supposed to declare if the post has no thumbnails, it should get the relative path to display the thumbnails defined for the category.
I've tried different ways to make it work but I can't find what's the problem. The only error I get is
Object of class Closure could not be converted to string
Thanks for any help

Answer 1

function(){ is a function definition, you can't concatenate that. Additionally, has_post_thumbnail is actually the WP function you want to use and that takes as its first parameter the post ID. So you should rewrite your code as follows.
$args = array( 'numberposts' => '3' );
$recent_posts = wp_get_recent_posts( $args );
foreach( $recent_posts as $recent ){
$output = '<a style="color:white;text-decoration:none;" href="'. get_permalink($recent["ID"]) . '">
<article class="post post_home" style="background-image: url(';
if( has_post_thumbnail($recent["ID"]) ) {
$output .= get_the_post_thumbnail_url( $recent["ID"], 'cover' );
} elseif ( has_category( 'positive-morning' ) ) {
$output .= get_bloginfo('template_directory') . '/img/BG/2-Morning.jpg';
} elseif ( has_category( 'positive-talks' ) ) {
$output .= get_bloginfo('template_directory') . '/img/BG/2-Talks.jpg';
}
$output .= ' background-position : center; background-size :cover;">
<h2>'. $recent["post_title"] .'</h2></article>';
echo $output;
}

Answer 2

Theres a few things missing here. You're not setting up postdata inside your loop and you don't need a function inside it either, also personally I don't like concatinating strings together inside PHP tags to make HTML so I used ob_start() and ob_get_clean() to build the HTML. try something like this...
<?php
$args = array( 'numberposts' => '3' );
$recent_posts = wp_get_recent_posts( $args );
ob_start();
foreach( $recent_posts as $recent ){
setup_postdata($recent); ?>
<a style="color:white;text-decoration:none;" href="<?php get_permalink($recent["ID"])?>">
<article class="post post_home" style="background-image: url(<?php
if( has_post_thumbnail() ) {
echo get_the_post_thumbnail_url( $recent["ID"], 'cover' );
} elseif ( has_category( 'positive-morning' ) ) {
echo get_bloginfo('template_directory') . '/img/BG/2-Morning.jpg';
} elseif ( has_category( 'positive-talks' ) ) {
echo get_bloginfo('template_directory') . '/img/BG/2-Talks.jpg';
}; ?>
); background-position : center; background-size :cover;">
<h2><?php echo $recent["post_title"] ?></h2></article>
<?php
wp_reset_postdata();
}
echo ob_get_clean(); ?>
Fair warning I haven't tested any of that code