Entendiendo el Loop de WordPress

01-loop-basico.php

<?php
if ( have_posts() ) :
  while ( have_posts() ) : 
    the_post();
    //contenido del loop (template tags, html, etc)
  endwhile;
endif; 
?>

02-twentysixteen-single.php

<?php
/**
 * The template for displaying all single posts and attachments
 *
 * @package WordPress
 * @subpackage Twenty_Sixteen
 * @since Twenty Sixteen 1.0
 */
get_header(); ?>

	<div id="primary" class="content-area">
		<main id="main" class="site-main" role="main">

		<?php
		// Start the loop.
		while ( have_posts() ) : the_post();
			get_template_part( 'template-parts/content', 'single' );
			// If comments are open or we have at least one comment, load up the comment template.
			if ( comments_open() || get_comments_number() ) {
				comments_template();
			}
			// Previous/next post navigation.
			the_post_navigation( array(
				'next_text' => '<span class="meta-nav" aria-hidden="true">' . esc_html__( 'Next', 'twentysixteen' ) . '</span> ' .
					'<span class="screen-reader-text">' . esc_html__( 'Next post:', 'twentysixteen' ) . '</span> ' .
					'<span class="post-title">%title</span>',
				'prev_text' => '<span class="meta-nav" aria-hidden="true">' . esc_html__( 'Previous', 'twentysixteen' ) . '</span> ' .
					'<span class="screen-reader-text">' . esc_html__( 'Previous post:', 'twentysixteen' ) . '</span> ' .
					'<span class="post-title">%title</span>',
			) );
		// End of the loop.
		endwhile;
		?>

		</main><!-- .site-main -->

		<?php get_sidebar( 'content-bottom' ); ?>

	</div><!-- .content-area -->

<?php get_sidebar(); ?>
<?php get_footer(); ?>

03-template-tags-loop.php

<?php
if ( have_posts() ) :
  while ( have_posts() ) : 
    the_post(); ?>
    <div class="entrada">
      <a href="<?php the_permalink(); ?>"><?php the_title(); ?></a> 
      <div class="contenido">
        <?php the_content(); ?>
      </div>
    </div> <?php
  endwhile; 
endif;
?>

04-custom-loop-wp-query.php

<?php
$misEntradas = new WP_Query( 'author_name=avillegasn' );
if ( $misEntradas->have_posts() ) :
  while ( $misEntradas->have_posts() ): 
    $misEntradas->the_post();
    // renderiza las entradas aquí
  endwhile;
endif;
?>

05-custom-loop-complejo.php

<?php
$args = array(
	'post_type'  => 'amigo',
	'meta_key'   => 'edad',
	'orderby'    => 'meta_value_num',
	'order'      => 'ASC',
	'meta_query' => array(
		array(
			'key'     => 'edad',
			'value'   => array( 18, 35 ),
			'compare' => 'BETWEEN',
		),
	),
);
$query = new WP_Query( $args );
?>

6-query-posts.php

<?php
query_posts( 'cat=1&tag=temas+plugins' );
if ( have_posts() ) :
  while ( have_posts() ) : the_post();
  // renderiza el contenido aqui (template tags, html, etc)
  endwhile;
endif;
?>

7-query-posts-query_string.php

<?php
// inicializa la variable global $query_string
global $query_string;
// manten el contenido del Loop original y añade la condicion de un único autor
query_posts( $query_string . "&author_name=avillegasn" );
?>

8-get-posts.php

<?php
$entradas_comunidad = get_posts( 'category_name=comunidad&posts_per_page=5' );
foreach( $entradas_comunidad as $post ) :
  setup_postdata( $post ); ?>
  <h1><a href="<?php the_permalink(); ?>"><?php the_title(); ?></a></h1><?php
  the_content();
endforeach;
?>

9-pre-get-posts.php

<?php
function mi_funcion_que_filtra_resultados_de_busquedas( $query ) {
  if ( ! is_admin() && $query->is_main_query() && $query->is_search() ) {
    $query->set( 'post_type', 'post' );
  }
}
add_action( 'pre_get_posts', 'mi_funcion_que_filtra_resultados_de_busquedas' );
?>