Wordpress - Image Upload from URL

you can write a php script, or make your own plugin of this code here, i used it in one of my projects where i had to import a large number of images.

first, get the image, and store it in your upload-directory:

$uploaddir = wp_upload_dir();
$uploadfile = $uploaddir['path'] . '/' . $filename;

$contents= file_get_contents('http://mydomain.com/folder/image.jpg');
$savefile = fopen($uploadfile, 'w');
fwrite($savefile, $contents);
fclose($savefile);

after that, we can insert the image into the media library:

$wp_filetype = wp_check_filetype(basename($filename), null );

$attachment = array(
    'post_mime_type' => $wp_filetype['type'],
    'post_title' => $filename,
    'post_content' => '',
    'post_status' => 'inherit'
);

$attach_id = wp_insert_attachment( $attachment, $uploadfile );

$imagenew = get_post( $attach_id );
$fullsizepath = get_attached_file( $imagenew->ID );
$attach_data = wp_generate_attachment_metadata( $attach_id, $fullsizepath );
wp_update_attachment_metadata( $attach_id, $attach_data );

and voila - here we go. you can also set various other parameters in the attachment array. if you got an array of urls or something like that, you can run the script in a loop - but be aware that the image functions take up a lot of time and memory to execute.

You can use the functions download_url() and wp_handle_sideload().

download_url()

Downloads a url to a local temporary file using the WordPress HTTP Class. Please note that the calling function must unlink() the file.

wp_handle_sideload()

Handle sideloads, which is the process of retrieving a media item from another server instead of a traditional media upload. This process involves sanitizing the filename, checking extensions for mime type, and moving the file to the appropriate directory within the uploads directory.

Example:

// Gives us access to the download_url() and wp_handle_sideload() functions
require_once( ABSPATH . 'wp-admin/includes/file.php' );

// URL to the WordPress logo
$url = 'http://s.w.org/style/images/wp-header-logo.png';
$timeout_seconds = 5;

// Download file to temp dir
$temp_file = download_url( $url, $timeout_seconds );

if ( !is_wp_error( $temp_file ) ) {

    // Array based on $_FILE as seen in PHP file uploads
    $file = array(
        'name'     => basename($url), // ex: wp-header-logo.png
        'type'     => 'image/png',
        'tmp_name' => $temp_file,
        'error'    => 0,
        'size'     => filesize($temp_file),
    );

    $overrides = array(
        // Tells WordPress to not look for the POST form
        // fields that would normally be present as
        // we downloaded the file from a remote server, so there
        // will be no form fields
        // Default is true
        'test_form' => false,

        // Setting this to false lets WordPress allow empty files, not recommended
        // Default is true
        'test_size' => true,
    );

    // Move the temporary file into the uploads directory
    $results = wp_handle_sideload( $file, $overrides );

    if ( !empty( $results['error'] ) ) {
        // Insert any error handling here
    } else {

        $filename  = $results['file']; // Full path to the file
        $local_url = $results['url'];  // URL to the file in the uploads dir
        $type      = $results['type']; // MIME type of the file

        // Perform any actions here based in the above results
    }

}

WordPress Plugin Directory - Grab & Save

This plugin allow you to grab image from remote url and save into your own wordpress media library. By doing so, you never worried if the remote image was removed by its owner. This also save you steps to download the image to local computer and upload again to your own wordpress.

After grabbing the image, wordpress will prompt you either to "insert into post" or "change attributes" just like after you upload an image.