wp-query-add-argument-post-title-like-search.php

<?php

add_filter('posts_where', 'hwk_wp_query_post_like', 10, 2);
function hwk_wp_query_post_like($where = '', &$wp_query){
    global $wpdb;
    if(!$post_like = $wp_query->get('post_like'))
        return $where;
    
    if(is_string($post_like))
        return $where .= ' AND ' . $wpdb->posts . '.post_title LIKE \'%' . esc_sql($wpdb->esc_like($post_like)) . '%\'';
    
    if(!is_array($post_like))
        return $where;
    
    if(!isset($post_like[0]) || (!is_string($post_like[0]) && !is_array($post_like[0])))
        return $where;
    
    $post_like = wp_parse_args($post_like, array(
        'relation'  => 'OR',
        'column'    => 'post_title',
    ));
    
    $post_title_like_array = array();
    $post_title_like_array[] = $post_like[0];
    
    if(is_array($post_like[0])){
        $post_title_like_array = array();
        foreach($post_like[0] as $k => $rule){
            $post_title_like_array[] = $rule;
        }
    }
    
    $where_addon = array();
    foreach($post_title_like_array as $keyword){
        $where_addon[] = $wpdb->posts . '.' . $post_like['column'] . ' LIKE \'%' . esc_sql($wpdb->esc_like($keyword)) . '%\'';
    }
    $where .= ' AND ( ' . implode(' ' . $post_like['relation'] . ' ', $where_addon) . ' )';

    return $where;
}

/*
// Usage:
// Post_title like 'Contact' OR 'Informations':
$query = new WP_Query(array(
    'post_type'         => 'page',
    'posts_per_page'    => -1,
    'post_like'         => array(
        'relation'  => 'OR',            // OR | AND - default: OR
        'column'    => 'post_title',    // post_title | post_content etc... - default: post_title
        array(
            'Contact',
            'Informations',
        )
    )
));

// Post_title like 'Contact' AND 'Informations':
$query = new WP_Query(array(
    'post_type'         => 'page',
    'posts_per_page'    => -1,
    'post_like'         => array(
        'relation'  => 'AND',
        array(
            'Contact',
            'Informations',
        )
    )
));

// Post_title like 'Contact':
$query = new WP_Query(array(
    'post_type'         => 'page',
    'posts_per_page'    => -1,
    'post_like'         => 'Contact'
));

// Post_content like 'Contact':
$query = new WP_Query(array(
    'post_type'         => 'page',
    'posts_per_page'    => -1,
    'post_like'         => array(
        'column'    => 'post_content',
        array(
            'Contact'
        )
    )
));
*/