wp_post_helper

example.php

<?php
require_once('/path/to/wordpress/wp-load.php');
require_once('class-wp_post_helper.php');

// initialize
$post = new wp_post_helper(array(
    'post_name'    => 'slug' ,			// slug
    'post_author'  => 1 ,			// author's ID
    'post_date'    => '2012/11/15 20:00:00' ,	// post date and time
    'post_type'    => 'posts' ,			// post type (you can use custom post type)
    'post_status'  => 'publish' ,		// post status, publish, draft and so on
    'post_title'   => 'title' ,			// post title
    'post_content' => 'content' ,		// post content
    'post_category'=> array(1, 2) ,		// category IDs in an array
    'post_tags'    => array('tag1', 'tag2') ,	// post tags in an array
));

// adding media
$post->add_media(
   '/path/to/wordpress/wp-content/uploads/hoge.jpg' ,	// absolute path to the madia file
   'tittle',		// titile of the media
   'description',	// description of the media
   'caption',		// caption of the media
   true			// true (set it as a featured image) or false (don't set is as a featured image)
);

// Download and add a media from URL.
//  remote_get_file() is in class-wp_post_helper.php.
//  When you pass a URL to the argument, it will download the file to wp_upload_dir and return the absolute path.
//  When it fails, return false.
if ( $media = remote_get_file('http://example.com/fuga.jpg') ) {
   $post->add_media($media, 'title', 'description', 'caption', false);
}

// adding a value to a custom field
$post->add_meta(
   'meta_key',	// meta key
   'meta_val',	// meta value
   true		// add it as unique (true) or not (false)
);

// adding a value as a format of Advanced Custom Field
$post->add_field(
   'field_xxxxxxxxxxxxx',	// key
   'field_val'			// value
);


// post
$post->insert();

// post-processing
unset($post);

wp_post_helper.php

<?php
/*
 en : https://gist.github.com/4084471
 ja : https://gist.github.com/4078027

License:
 Released under the GPL license
  http://www.gnu.org/copyleft/gpl.html

  Copyright 2013 (email : wokamoto1973@gmail.com)

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
*/

if (defined('ABSPATH')) :

require_once(ABSPATH . 'wp-admin/includes/image.php');
require_once(ABSPATH . 'wp-admin/includes/post.php');

class wp_post_helper {
	public $post;

	private $postid = false;
	private $attachment_id = array();

	private $tags   = array();	
	private $medias = array();
	private $metas  = array();
	private $fields = array();
	private $media_count = 0;
	private $terms  = array();

	function __construct($args = array()){
		$this->init($args);
	}

	// Get PostID
	public function postid(){
		return $this->postid;
	}

	// Get Attachment ID
	public function attachment_id(){
		return $this->attachment_id;
	}

	// Init Post Data
	public function init($args = array()){
		if (is_object($args))
			$args = (array)$args;
		$this->attachment_id = array();
		$this->tags   = array();
		$this->medias = array();
		$this->metas  = array();
		$this->fields = array();
		$this->media_count = 0;

		if (is_numeric($args)) {
			$post = get_post(intval($args));
			if ($post && isset($post->ID) && !is_wp_error($post)) {
				$this->post_id = $post->ID;
				$this->post = $post;
				return true;
			} else {
				return false;
			}
		} else {
			$this->post = get_default_post_to_edit();
			$this->post->post_category = null;
			if (is_array($args) && count($args) > 0)
				return $this->set($args);
			else
				return true;
		}
	}

	// Set Post Data
	public function set($args) {
		if (is_object($args))
			$args = (array)$args;
		if (!is_array($args))
			return false;

		if (isset($args['ID']) || isset($args['post_id'])) {
			$post_id = isset($args['ID']) ? $args['ID'] : $args['post_id'];
			$post = get_post($post_id, 'ARRAY_A');
			if (isset($post['ID'])) {
				$this->post_id  = $post_id;
				$this->post->ID = $post_id;
				unset($post['ID']);
				$this->set($post);
			}
			unset($post);
		}

		$post = $this->post;
		foreach ($post as $key => &$val) {
			if ($key !== 'ID' && isset($args[$key])) {
				$val = $args[$key];
			}
		}
		$this->post = $post;

		if (isset($args['post_tags'])) {
			$this->add_tags(
				is_array($args['post_tags'])
				? $args['post_tags']
				: explode(',', $args['post_tags'])
				);
		}

		return true;
	}

	// Add Post
	public function insert(){
		if (!isset($this->post))
			return false;

		$this->postid   = 0;
		$this->post->ID = 0;
		$postid = wp_insert_post($this->post);
		if ($postid && !is_wp_error($postid)) {
			$this->postid   = $postid;
			$this->post->ID = $postid;
			return $this->add_related_meta($postid) ? $postid : false;
		} else {
			$this->postid   = $postid;
			$this->post->ID = 0;
			return false;
		}
	}

	// Update Post
	public function update(){
		if (!isset($this->post))
			return false;

		$postid = 
			$this->postid
			? wp_update_post($this->post)
			: wp_insert_post($this->post);
		if ($postid && !is_wp_error($postid)) {
			$this->postid   = $postid;
			$this->post->ID = $postid;
			return $this->add_related_meta($postid) ? $postid : false;
		} else {
			$this->postid   = false;
			$this->post->ID = 0;
			return false;
		}
	}

	private function add_related_meta($postid){
		if (!$postid || is_wp_error($postid))
			return false;

		$this->postid   = $postid;

		// add Tags
		if (count($this->tags) > 0)
			$this->add_tags($this->tags);
		$this->tags = array();
			
		// add medias
		foreach ($this->medias as $key => $val) {
			$this->add_media($key, $val[0], $val[1], $val[2], $val[3]);
		}
		$this->medias = array();

		// add terms
		foreach ($this->terms as $taxonomy => $terms) {
			$this->add_terms($taxonomy, $terms);
		}
		$this->terms = array();

		// add Custom Fields
		foreach ($this->metas as $key => $val) {
			if (is_array($val))
				$this->add_meta($key, $val[0], isset($val[1]) ? $val[1] : true);
			else
				$this->add_meta($key, $val);
		}
		$this->metas = array();

		// add ACF Fields
		foreach ($this->fields as $key => $val) {
			$this->add_field($key, $val);
		}
		$this->fields = array();

		return true;
	}

	// Add Tag
	public function add_tags($tags = array()){
		$tags = is_array($tags) ? $tags : explode(',', $tags);
		foreach ($tags as $tag) {
			if (!empty($tag) && !array_search($tag, $this->tags))
				$this->tags[] = $tag;
		}
		unset($tags);

		if ($this->postid) {
			$tags = implode(',', $this->tags);
			$this->tags = array();
			return wp_add_post_tags($this->postid, $tags);
		}
	}

	// add terms
	public function add_terms($taxonomy, $terms){
		if (!$this->postid) {
			if (!isset($this->terms[$taxonomy]))
				$this->terms[$taxonomy] = array();
			foreach((array)$terms as $term) {
				if (array_search($term, $this->terms[$taxonomy]) === FALSE)
					$this->terms[$taxonomy][] = $term;
			}
		} else {
			return wp_set_object_terms($this->postid, $terms, $taxonomy);
		}
	}

	// Add Media
	public function add_media($filename, $title = null, $content = null, $excerpt = null, $thumbnail = false){
		if (!$this->postid) {
			$this->medias[$filename] = array(
				$title,
				$content,
				$excerpt,
				$thumbnail,
				);
			return;
		}
	
		if ( $filename && file_exists($filename) ) {
			$mime_type = '';
			$wp_filetype = wp_check_filetype(basename($filename), null);
			if (isset($wp_filetype['type']) && $wp_filetype['type'])
				$mime_type = $wp_filetype['type'];
			unset($wp_filetype);
			
			$title = isset($title) ? $title : preg_replace('/\.[^.]+$/', '', basename($filename));
			$content = isset($content) ? $content : $title;
			$excerpt = isset($excerpt) ? $excerpt : $content;
			$attachment = array(
				'post_mime_type' => $mime_type ,
				'post_parent'    => $this->postid ,
				'post_author'    => $this->post->post_author ,
				'post_title'     => $title ,
				'post_content'   => $content ,
				'post_excerpt'   => $excerpt ,
				'post_status'    => 'inherit',
				'menu_order'     => $this->media_count + 1,
			);
			if (isset($this->post->post_name) && $this->post->post_name)
				$attachment['post_name'] = $this->post->post_name;
			$attachment_id = wp_insert_attachment($attachment, $filename, $this->postid);
			unset($attachment);

			if (!is_wp_error($attachment_id)) {
				$this->media_count++;
				$this->attachment_id[] = $attachment_id;
				$attachment_data = wp_generate_attachment_metadata($attachment_id, $filename);
				wp_update_attachment_metadata($attachment_id,  $attachment_data);
				unset($attachment_data);
				if ($thumbnail)
					set_post_thumbnail($this->postid, $attachment_id);
				return $attachment_id;
			} else {
				return false;
			}
		} else {
			return false;
		}
	}

	// Add Custom Field
	public function add_meta($metakey, $val, $unique = true){
		if (!$this->postid)
			$this->metas[$metakey] = array($val, $unique);
		else
			return $val ? add_post_meta($this->postid, $metakey, $val, $unique) : false;
	}

	// Add Advanced Custom Field
	public function add_field($field_key, $val){
		if (!$this->postid)
			$this->fields[$field_key] = $val;
		else
			return $val ? update_field($field_key, $val, $this->postid) : false;
	}
}

function remote_get_file($url = null, $file_dir = '') {
	if (!$url)
		return false;

	if (empty($file_dir)) {
		 $upload_dir = wp_upload_dir();
		 $file_dir = isset($upload_dir['path']) ? $upload_dir['path'] : '';
	}
	$file_dir = trailingslashit($file_dir);

	// make directory
	if (!file_exists($file_dir)) {
		$dirs = explode('/', $file_dir);
		$subdir = '/';
		foreach ($dirs as $dir) {
			if (!empty($dir)) {
				$subdir .= $dir . '/';
				if (!file_exists($subdir)) {
					mkdir($subdir);
				}
			}
		}
	}

	// remote get!
	$photo = $file_dir . basename($url);
	if ( !file_exists($photo) ) {
		$response = wp_remote_get($url);
		if ( !is_wp_error($response) && $response["response"]["code"] === 200 ) {
			$photo_data = $response["body"];
			file_put_contents($photo, $photo_data);
			unset($photo_data);
		} else {
			$photo = false;
		}
		unset($response);
	}
	return file_exists($photo) ? $photo : false;
}

endif;