How to save media files under custom folder without changing wp-config.php or changing media settings

Question

I want to upload images in a unique folder. Then retrieve the path of this image saved on server like

http://example.com/wp-content/uploads/myimages/image1.jpg

Now I want to save this URL in a post having custom field as url.

I'll be overwriting the posts on regular basis as well as replacing corresponding images, so I don't want to keep the images related to previous posts (deleted posts) on my server (otherwise it would increase the memory on server). I want to delete all the images from myimages folder. I don't want to change the default path for uploads. Here's my code for creating the post:

$new_post = array(
'post_title' => $phototitle,
'post_status' => 'publish',
'post_author' => 1,
'post_type' => 'post',
'post_category' => array(328)
);

$postid=wp_insert_post($new_post);
update_field('field_521c73f75a652',$photoid,$postid);
update_field('field_521c74a65a653',$phototitle,$postid);
update_field('field_521c74b25a654',$photourl,$postid);
update_field('field_521c74be5a655',$details,$postid);
update_field('field_521c77e72f9a6',$countinarr,$postid);

require_once(ABSPATH . 'wp-admin/includes/media.php');
require_once(ABSPATH . 'wp-admin/includes/file.php');
require_once(ABSPATH . 'wp-admin/includes/image.php');
$image = media_sideload_image($photourl, $postid, $phototitle);

$path = (string)$image;
$arr = (explode("'",$path));
$url = $arr[1];

update_field('field_521c758095f55',$url,$postid);

Please tell me how to change this upload path without making any change in wp-config.php or media settings.

Answer 1

Here is simple function to create your own sub directory for every upload.

function kv_custom_image_dir( $pathdata ) {
    $subdir = '/uploads_img'.$pathdata['subdir'];
    $pathdata['path'] = str_replace($pathdata['subdir'], $subdir, $pathdata['path']);
    $pathdata['url'] = str_replace($pathdata['subdir'], $subdir, $pathdata['url']);
    $pathdata['subdir'] = str_replace($pathdata['subdir'], $subdir, $pathdata['subdir']);
    return $pathdata;
}
add_filter( 'upload_dir', 'kv_custom_image_dir' );

From my above code, I changed my images folder as uploads_img, you can change yours likewise.

If you want more information, I wrote a tutorial for changing upload directories for every custom upload, take a look at my blog:

Answer 2

Notice: Haven't tested my idea or code provided below.

*media_sideload_image* calls *wp_handle_upload* function which, suprisingly, handles file upload.

Upload dir is set via *wp_upload_dir* function. This function has a filter which can be used to modify it's output (see http://core.trac.wordpress.org/browser/tags/3.6/wp-includes/functions.php#L1607):

$uploads = apply_filters( 'upload_dir',
array(
    'path'    => $dir,
    'url'     => $url,
    'subdir'  => $subdir,
    'basedir' => $basedir,
    'baseurl' => $baseurl,
    'error'   => false,
) );

So hooking into that filter via:

add_filter( 'upload_dir', 'my_upload_dir_function' );

function my_upload_dir_function( $uploads ){
    if( isset( $_POST['my_check_post_var'] ) && $_POST['my_check_post_var'] == 'my_check_var_value' ){
        return array(
            'path'    => $dir, //have to be set
            'url'     => $url, //have to be set
            'subdir'  => $subdir, //have to be set
            'basedir' => $basedir, //have to be set
            'baseurl' => $baseurl, //have to be set
            'error'   => false,
        );
    }else{
        return $uploads;
    }
}

The code pressume, that you have a hidden field in your code which set's a check var with specific value agains you check in your filter. If that $_POST var is not present or has a different value, you return original array - thus you won't break a standard image uploads.

And of course, you have to create all variables used in the filter, eg. $dir, $url etc. Check http://core.trac.wordpress.org/browser/tags/3.6/wp-includes/functions.php#L1525 to get and idea how WP does this.