How to make a shortcode to list category posts with sorting based on custom field value

Question

I just switched to a new theme and don't want to override the template files. In my old theme I had a custom sidebar.php file with following code above the dynamic widget part. For new theme, I want to do this with a shortcode instead and just use a text widget to place it in the sidebar. How can I convert this to a shortcode?

<aside id="my-listings" class="widget widget-my-listings">
    <h2 class="widget-title">Featured Listings</h2>
    <ul>
        <?php
            global $post;
            $listings = get_posts('category=3&numberposts=-1&orderby=meta_value&meta_key=price&order=DESC');
            foreach($listings as $post) :
        ?>
        <li><a href="<?php the_permalink(); ?>"><?php
        if(get_post_meta($post->ID, "alternate_title", true)) {
            echo get_post_meta($post->ID, "alternate_title", true);
        } else {
            the_title();
        } ?></a></li>
        <?php endforeach; ?>
    </ul>
</aside>

Answer 1

Use this shortcode.

[mylistingswidget]

This is the code place in your functions.php

<?php

add_shortcode( 'mylistingswidget', 'my_listings_widget' );

function my_listings_widget( $atts ) {
    ob_start();
    ?>
    <aside id="my-listings" class="widget widget-my-listings">
        <h2 class="widget-title">Featured Listings</h2>
        <ul>
            <?php
            global $post;
            $listings = get_posts('category=3&numberposts=-1&orderby=meta_value&meta_key=price&order=DESC');
            foreach($listings as $post) :
                ?>
                <li><a href="<?php the_permalink(); ?>"><?php
                        if(get_post_meta($post->ID, "alternate_title", true)) {
                            echo get_post_meta($post->ID, "alternate_title", true);
                        } else {
                            the_title();
                        } ?></a></li>
            <?php endforeach; ?>
        </ul>
    </aside>
<?php
    return ob_get_clean();
}