在短代码中显示特定类别的帖子标题（wordPress）

Question

Trying to write my first short-code that displays all post-titles in a specific Category. But it is not displaying the actual results, just the short code. Here is what I have so far in my child theme's functions.php file:

function posts_in_cat() {
echo '<ul>';
query_posts('cat=3'); while (have_posts()) : the_post();
echo ('<li><a href="' . the_permalink() . '">' . the_title() . '</a></li>');
endwhile;
wp_reset_query();
echo '</ul>';
}
add_shortcode( 'display_posts_in_cat', 'posts_in_cat' );

And then I am calling the short code, like so [display_posts_in_cat] .

Any help would be greatly appreciated as I try and learn this.

EDIT: I have gotten it to display but the link itself is being echo-ed in front of the title in text. Also, it is not displaying more than 10 of the titles and I want it to display them all. Any ideas...?? Thanks.

Answer 1

First and foremost, avoid using query_posts() – it's inefficient. Check out this SO answer for the skinny.

Additionally, shortcodes shouldn't make use of echo statements. Shortcodes only return text. Put simply, WordPress has PHP internally that says "when this specific shortcode is entered into the editor, replace it with the text returned from this function." Using echo causes you to immediately print those statements to the screen, rather than returning to WordPress so that it can continue with its regular process. More on the WP Codex .

And, finally, shortcode functions require $atts as a parameter.

So, with all that said, here's how I would rewrite your function:

<?php

function posts_in_cat( $atts ) {
    $atts = shortcode_atts( array(
        'cat' => '',
    ), $atts );

    if ( empty( $atts['cat'] ) ) {
        // If category provided, exit early
        return;
    }

    $args = array(
        'category' => $atts['cat'],
        // Disable pagination
        'posts_per_page' => -1
    );

    $posts_list = get_posts( $args );

    if ( empty( $posts_list) ) {
        // If no posts, exit early
        return;
    }

    $opening_tag = '<ul>';
    $closing_tag = '</ul>';
    $post_content = '';

    foreach ( $posts_list as $post_cat ) {
        $post_content .= '<li><a href="' . esc_url( get_permalink( $post_cat->ID ) )  . '">' . esc_html( get_the_title( $post_cat->ID ) ) . '</a></li>';
    }

    return $opening_tag . $post_content . $closing_tag;
}
add_shortcode( 'display_posts_in_cat', 'posts_in_cat' );

I'm just adding all of the content you were echo ing into a handful of variables, and then returning them, concatenated, at the end. Also, I added in an if statement to exit early if there aren't any posts in the category. That way you don't have an empty <ul> element cluttering up the page.

I've also escaped the outputs, which you can read about on the Codex.

Answer 2

Please try this:

 function posts_in_cat() { ?>
<ul class="posts">
<?php query_posts('cat=3&showposts=50'); while (have_posts()) : the_post(); 
 ?>
    <li><a href='<?php the_permalink() ?>'><?php the_title(); ?></a></li>
<?php endwhile; ?>

<?php wp_reset_query(); ?>
  </ul>

  <?php

    }
    add_shortcode( 'display_posts_in_cat', 'posts_in_cat' );