get_images_from_content( $this->get_post_content( $post_id, $post ) );
}
/**
* Grabs the images from the content.
*
* @param string $content The post content string.
*
* @return array An array of image URLs.
*/
public function get_images_from_content( $content ) {
if ( ! is_string( $content ) ) {
return [];
}
$content_images = $this->get_img_tags_from_content( $content );
$images = array_map( [ $this, 'get_img_tag_source' ], $content_images );
$images = array_filter( $images );
$images = array_unique( $images );
$images = array_values( $images ); // Reset the array keys.
return $images;
}
/**
* Gets the image tags from a given content string.
*
* @param string $content The content to search for image tags.
*
* @return array An array of `![]()
` tags.
*/
private function get_img_tags_from_content( $content ) {
if ( strpos( $content, ']+>`', $content, $matches );
if ( isset( $matches[0] ) ) {
return $matches[0];
}
return [];
}
/**
* Retrieves the image URL from an image tag.
*
* @param string $image Image HTML element.
*
* @return string|bool The image URL on success, false on failure.
*/
private function get_img_tag_source( $image ) {
preg_match( '`src=(["\'])(.*?)\1`', $image, $matches );
if ( isset( $matches[2] ) && filter_var( $matches[2], FILTER_VALIDATE_URL ) ) {
return $matches[2];
}
return false;
}
/**
* Retrieves the post content we want to work with.
*
* @param int $post_id The post ID.
* @param WP_Post|array|null $post The post.
*
* @return string The content of the supplied post.
*/
private function get_post_content( $post_id, $post ) {
if ( $post === null ) {
$post = get_post( $post_id );
}
if ( $post === null ) {
return '';
}
/**
* Filter: 'wpseo_pre_analysis_post_content' - Allow filtering the content before analysis.
*
* @api string $post_content The Post content string.
*/
$content = apply_filters( 'wpseo_pre_analysis_post_content', $post->post_content, $post );
if ( ! is_string( $content ) ) {
$content = '';
}
return $content;
}
}