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function is not described

WP_REST_Posts_Controller::get_items() WP 4.7.0

Retrieves a collection of posts.

This is a method of the class: WP_REST_Posts_Controller

Hooks from the method
Return

WP_REST_Response/WP_Error. Response object on success, or WP_Error object on failure.

Usage

$WP_REST_Posts_Controller = new WP_REST_Posts_Controller();
$var = $WP_REST_Posts_Controller->get_items( $request );
$request(WP_REST_Request) (required)
Full details about the request.

Changelog

Since 4.7.0 Introduced.

Code of WP REST Posts Controller::get items: wp-includes/rest-api/endpoints/class-wp-rest-posts-controller.php WP 5.4.1

<?php
public function get_items( $request ) {

	// Ensure a search string is set in case the orderby is set to 'relevance'.
	if ( ! empty( $request['orderby'] ) && 'relevance' === $request['orderby'] && empty( $request['search'] ) ) {
		return new WP_Error(
			'rest_no_search_term_defined',
			__( 'You need to define a search term to order by relevance.' ),
			array( 'status' => 400 )
		);
	}

	// Ensure an include parameter is set in case the orderby is set to 'include'.
	if ( ! empty( $request['orderby'] ) && 'include' === $request['orderby'] && empty( $request['include'] ) ) {
		return new WP_Error(
			'rest_orderby_include_missing_include',
			__( 'You need to define an include parameter to order by include.' ),
			array( 'status' => 400 )
		);
	}

	// Retrieve the list of registered collection query parameters.
	$registered = $this->get_collection_params();
	$args       = array();

	/*
	 * This array defines mappings between public API query parameters whose
	 * values are accepted as-passed, and their internal WP_Query parameter
	 * name equivalents (some are the same). Only values which are also
	 * present in $registered will be set.
	 */
	$parameter_mappings = array(
		'author'         => 'author__in',
		'author_exclude' => 'author__not_in',
		'exclude'        => 'post__not_in',
		'include'        => 'post__in',
		'menu_order'     => 'menu_order',
		'offset'         => 'offset',
		'order'          => 'order',
		'orderby'        => 'orderby',
		'page'           => 'paged',
		'parent'         => 'post_parent__in',
		'parent_exclude' => 'post_parent__not_in',
		'search'         => 's',
		'slug'           => 'post_name__in',
		'status'         => 'post_status',
	);

	/*
	 * For each known parameter which is both registered and present in the request,
	 * set the parameter's value on the query $args.
	 */
	foreach ( $parameter_mappings as $api_param => $wp_param ) {
		if ( isset( $registered[ $api_param ], $request[ $api_param ] ) ) {
			$args[ $wp_param ] = $request[ $api_param ];
		}
	}

	// Check for & assign any parameters which require special handling or setting.
	$args['date_query'] = array();

	// Set before into date query. Date query must be specified as an array of an array.
	if ( isset( $registered['before'], $request['before'] ) ) {
		$args['date_query'][0]['before'] = $request['before'];
	}

	// Set after into date query. Date query must be specified as an array of an array.
	if ( isset( $registered['after'], $request['after'] ) ) {
		$args['date_query'][0]['after'] = $request['after'];
	}

	// Ensure our per_page parameter overrides any provided posts_per_page filter.
	if ( isset( $registered['per_page'] ) ) {
		$args['posts_per_page'] = $request['per_page'];
	}

	if ( isset( $registered['sticky'], $request['sticky'] ) ) {
		$sticky_posts = get_option( 'sticky_posts', array() );
		if ( ! is_array( $sticky_posts ) ) {
			$sticky_posts = array();
		}
		if ( $request['sticky'] ) {
			/*
			 * As post__in will be used to only get sticky posts,
			 * we have to support the case where post__in was already
			 * specified.
			 */
			$args['post__in'] = $args['post__in'] ? array_intersect( $sticky_posts, $args['post__in'] ) : $sticky_posts;

			/*
			 * If we intersected, but there are no post ids in common,
			 * WP_Query won't return "no posts" for post__in = array()
			 * so we have to fake it a bit.
			 */
			if ( ! $args['post__in'] ) {
				$args['post__in'] = array( 0 );
			}
		} elseif ( $sticky_posts ) {
			/*
			 * As post___not_in will be used to only get posts that
			 * are not sticky, we have to support the case where post__not_in
			 * was already specified.
			 */
			$args['post__not_in'] = array_merge( $args['post__not_in'], $sticky_posts );
		}
	}

	// Force the post_type argument, since it's not a user input variable.
	$args['post_type'] = $this->post_type;

	/**
	 * Filters the query arguments for a request.
	 *
	 * Enables adding extra arguments or setting defaults for a post collection request.
	 *
	 * @since 4.7.0
	 *
	 * @link https://developer.wordpress.org/reference/classes/wp_query/
	 *
	 * @param array           $args    Key value array of query var to query value.
	 * @param WP_REST_Request $request The request used.
	 */
	$args       = apply_filters( "rest_{$this->post_type}_query", $args, $request );
	$query_args = $this->prepare_items_query( $args, $request );

	$taxonomies = wp_list_filter( get_object_taxonomies( $this->post_type, 'objects' ), array( 'show_in_rest' => true ) );

	if ( ! empty( $request['tax_relation'] ) ) {
		$query_args['tax_query'] = array( 'relation' => $request['tax_relation'] );
	}

	foreach ( $taxonomies as $taxonomy ) {
		$base        = ! empty( $taxonomy->rest_base ) ? $taxonomy->rest_base : $taxonomy->name;
		$tax_exclude = $base . '_exclude';

		if ( ! empty( $request[ $base ] ) ) {
			$query_args['tax_query'][] = array(
				'taxonomy'         => $taxonomy->name,
				'field'            => 'term_id',
				'terms'            => $request[ $base ],
				'include_children' => false,
			);
		}

		if ( ! empty( $request[ $tax_exclude ] ) ) {
			$query_args['tax_query'][] = array(
				'taxonomy'         => $taxonomy->name,
				'field'            => 'term_id',
				'terms'            => $request[ $tax_exclude ],
				'include_children' => false,
				'operator'         => 'NOT IN',
			);
		}
	}

	$posts_query  = new WP_Query();
	$query_result = $posts_query->query( $query_args );

	// Allow access to all password protected posts if the context is edit.
	if ( 'edit' === $request['context'] ) {
		add_filter( 'post_password_required', '__return_false' );
	}

	$posts = array();

	foreach ( $query_result as $post ) {
		if ( ! $this->check_read_permission( $post ) ) {
			continue;
		}

		$data    = $this->prepare_item_for_response( $post, $request );
		$posts[] = $this->prepare_response_for_collection( $data );
	}

	// Reset filter.
	if ( 'edit' === $request['context'] ) {
		remove_filter( 'post_password_required', '__return_false' );
	}

	$page        = (int) $query_args['paged'];
	$total_posts = $posts_query->found_posts;

	if ( $total_posts < 1 ) {
		// Out-of-bounds, run the query again without LIMIT for total count.
		unset( $query_args['paged'] );

		$count_query = new WP_Query();
		$count_query->query( $query_args );
		$total_posts = $count_query->found_posts;
	}

	$max_pages = ceil( $total_posts / (int) $posts_query->query_vars['posts_per_page'] );

	if ( $page > $max_pages && $total_posts > 0 ) {
		return new WP_Error(
			'rest_post_invalid_page_number',
			__( 'The page number requested is larger than the number of pages available.' ),
			array( 'status' => 400 )
		);
	}

	$response = rest_ensure_response( $posts );

	$response->header( 'X-WP-Total', (int) $total_posts );
	$response->header( 'X-WP-TotalPages', (int) $max_pages );

	$request_params = $request->get_query_params();
	$base           = add_query_arg( urlencode_deep( $request_params ), rest_url( sprintf( '%s/%s', $this->namespace, $this->rest_base ) ) );

	if ( $page > 1 ) {
		$prev_page = $page - 1;

		if ( $prev_page > $max_pages ) {
			$prev_page = $max_pages;
		}

		$prev_link = add_query_arg( 'page', $prev_page, $base );
		$response->link_header( 'prev', $prev_link );
	}
	if ( $max_pages > $page ) {
		$next_page = $page + 1;
		$next_link = add_query_arg( 'page', $next_page, $base );

		$response->link_header( 'next', $next_link );
	}

	return $response;
}