WP Image Cropping Function

gistfile1.txt

<?php /**
 * On the fly image cropping based on WP 3.5 image editor
 *
 * @since 1.0
 *
 * @param    int     $id
 * @param    int     $width
 * @param    int     $height
 * @param    boolean $crop
 * @return   string
 */
function cv_resize( $id = 0, $width = 50, $height = 50, $crop = true ){

  // Check if attachment is an image
  if ( !$id || !wp_attachment_is_image($id) )
    return false;

  $upload_dir = wp_upload_dir();
  $img_meta = wp_get_attachment_metadata( $id );

  if( empty($img_meta) )
    return false;

  // attachment url converted to image path
  $file = $upload_dir['basedir'] . '/' . $img_meta['file'];

  $image = wp_get_image_editor( $file );

  // legacy error explanation.
  if ( is_wp_error( $image ) )
    return false;

  // generate intended file name and check if the image exists.
  $new_file_path = $image->generate_filename($suffix = $width.'x'.$height);

  // If this file already exists, return the image url.
  if(file_exists($new_file_path))
    return str_replace($upload_dir['basedir'], $upload_dir['baseurl'], $new_file_path);

  // resize image and save
  $image->resize( $width, $height, $crop );
  $new_image_info = $image->save();

  // legacy error explanation.
  if ( is_wp_error( $new_image_info ) )
    return false;

  // convert path to url
  $url = str_replace($upload_dir['basedir'], $upload_dir['baseurl'], $new_image_info['path']);

  return $url;
}

function cv_resize_cached( $id = 0, $width = 50, $height = 50, $crop = true, $timeout = HOUR_IN_SECONDS ){
  $transient = 'cv_gallery_'.$id.'_'.$width.'_'.$height.'_'.$crop;

  if ( false === ( $result = get_transient( $transient ) ) ) {
    $result = cv_resize( $id, $width, $height, $crop );
    if( !empty( $result ) )
      set_transient( $transient, $result, $timeout );
  }
  return $result;
}

function cv_resize_thumbnail( $id = 0, $width = 50, $height = 50, $crop = true, $attr = '' ){

    $src = cv_resize_cached( $id, $width, $height, $crop );
    $hwstring = image_hwstring($width, $height);
    $size = $width . 'x' . $height;
    $attachment = get_post($id);

    $default_attr = array(
      'src' => $src,
      'class' => "attachment-$size",
      'alt' => trim(strip_tags( get_post_meta($id, '_wp_attachment_image_alt', true) )), // Use Alt field first
    );

    if ( empty($default_attr['alt']) )
      $default_attr['alt'] = trim(strip_tags( $attachment->post_excerpt )); // If not, Use the Caption
    if ( empty($default_attr['alt']) )
      $default_attr['alt'] = trim(strip_tags( $attachment->post_title )); // Finally, use the title


    $attr = wp_parse_args($attr, $default_attr);
    $attr = apply_filters( 'wp_get_attachment_image_attributes', $attr, $attachment );
    $attr = array_map( 'esc_attr', $attr );
    $html = rtrim("<img $hwstring");
    foreach ( $attr as $name => $value ) {
      $html .= " $name=" . '"' . $value . '"';
    }
    $html .= ' />';

  return $html;
}

function cv_resize_gallery( $ids = array(), $width = 50, $height = 50, $crop = true, $timeout = DAY_IN_SECONDS ){
  $list = implode('_', $ids);
  $transient = 'cv_gallery_'.$list.'_'.$width.'_'.$height.'_'.$crop;

  if ( false === ( $result = get_transient( $transient ) ) ) {
    $result = array();
    foreach ($ids as $id) {
      $result[] = cv_resize( $id, $width, $height, $crop );
    }

    set_transient( $transient, $result, $timeout );

  }
  return $result;
}

function cv_resize_sizes( $id = 0, $sizes = array(), $crop = true, $timeout = DAY_IN_SECONDS ){

  $dimensions = array_map(function($item) { return $item['width'].'x'.$item['height']; }, $sizes);

  $output = implode('_', $dimensions);

  $transient = 'cv_sizes_'.$id.'_'.md5($output).'_'.$crop;



  if ( false === ( $result = get_transient( $transient ) ) ) {
    $result = array();
    foreach ($sizes as $size) {
      $width = $size['width'];
      $height = $size['height'];
      $result[] = cv_resize( $id, $width, $height, $crop );
    }

    set_transient( $transient, $result, $timeout );

  }
  return $result;
}

function tt_get_resized_attachment_url( $id = 0, $width = 50, $height = 50, $crop = true ) {
  return ( defined('WPCOM_IS_VIP_ENV') && true === WPCOM_IS_VIP_ENV ) ? wpcom_vip_get_resized_attachment_url( $id, $width, $height, $crop ) : cv_resize_cached( $id, $width, $height, $crop );
}