[wp-trac] [WordPress Trac] #15311: dynamic image resize (on the fly) using already available functions

[WordPress Trac]

#15311: dynamic image resize (on the fly) using already available functions
-------------------------+--------------------------------------------------
 Reporter:  vteixeira    |       Owner:                 
     Type:  enhancement  |      Status:  new            
 Priority:  normal       |   Milestone:  Awaiting Review
Component:  Media        |     Version:  3.1            
 Severity:  normal       |    Keywords:  dev-feedback   
-------------------------+--------------------------------------------------

Comment(by vteixeira):

 I have a new version that should work without problems for a subfolder
 install (the previous version doesn't work with subfolder installs if I
 pass the image url instead of the ID).

 Also I removed the possibility to define the image quality because when I
 pass this variable WordPress renames the images differently, adding the
 image quality on the file name instead of the sizes. This caused many
 problems with the if statements to check if the image exists. So I decided
 to remove it.

 {{{
 /*
  * Resize images dynamically using wp built in functions
  * Victor Teixeira
  *
  * php 5.2+
  *
  * Exemplo de uso:
  *
  * <?php
  * $thumb = get_post_thumbnail_id();
  * $image = vt_resize( $thumb, '', 140, 110, true );
  * ?>
  * <img src="<?php echo $image[url]; ?>" width="<?php echo $image[width];
 ?>" height="<?php echo $image[height]; ?>" />
  *
  * @param int $attach_id
  * @param string $img_url
  * @param int $width
  * @param int $height
  * @param bool $crop
  * @return array
  */
 function vt_resize( $attach_id = null, $img_url = null, $width, $height,
 $crop = false ) {

         // this is an attachment, so we have the ID
         if ( $attach_id ) {

                 $image_src = wp_get_attachment_image_src( $attach_id,
 'full' );
                 $file_path = get_attached_file( $attach_id );

         // this is not an attachment, let's use the image url
         } else if ( $img_url ) {

                 $file_path = parse_url( $img_url );
                 $file_path = $_SERVER['DOCUMENT_ROOT'] .
 $file_path['path'];

                 //$file_path = ltrim( $file_path['path'], '/' );
                 //$file_path = rtrim( ABSPATH, '/' ).$file_path['path'];

                 $orig_size = getimagesize( $file_path );

                 $image_src[0] = $img_url;
                 $image_src[1] = $orig_size[0];
                 $image_src[2] = $orig_size[1];
         }

         $file_info = pathinfo( $file_path );
         $extension = '.'. $file_info['extension'];

         // the image path without the extension
         $no_ext_path = $file_info['dirname'].'/'.$file_info['filename'];

         $cropped_img_path =
 $no_ext_path.'-'.$width.'x'.$height.$extension;

         // checking if the file size is larger than the target size
         // if it is smaller or the same size, stop right here and return
         if ( $image_src[1] > $width || $image_src[2] > $height ) {

                 // the file is larger, check if the resized version
 already exists (for $crop = true but will also work for $crop = false if
 the sizes match)
                 if ( file_exists( $cropped_img_path ) ) {

                         $cropped_img_url = str_replace( basename(
 $image_src[0] ), basename( $cropped_img_path ), $image_src[0] );

                         $vt_image = array (
                                 'url' => $cropped_img_url,
                                 'width' => $width,
                                 'height' => $height
                         );

                         return $vt_image;
                 }

                 // $crop = false
                 if ( $crop == false ) {

                         // calculate the size proportionaly
                         $proportional_size = wp_constrain_dimensions(
 $image_src[1], $image_src[2], $width, $height );
                         $resized_img_path =
 $no_ext_path.'-'.$proportional_size[0].'x'.$proportional_size[1].$extension;

                         // checking if the file already exists
                         if ( file_exists( $resized_img_path ) ) {

                                 $resized_img_url = str_replace( basename(
 $image_src[0] ), basename( $resized_img_path ), $image_src[0] );

                                 $vt_image = array (
                                         'url' => $resized_img_url,
                                         'width' => $proportional_size[0],
                                         'height' => $proportional_size[1]
                                 );

                                 return $vt_image;
                         }
                 }

                 // no cache files - let's finally resize it
                 $new_img_path = image_resize( $file_path, $width, $height,
 $crop );
                 $new_img_size = getimagesize( $new_img_path );
                 $new_img = str_replace( basename( $image_src[0] ),
 basename( $new_img_path ), $image_src[0] );

                 // resized output
                 $vt_image = array (
                         'url' => $new_img,
                         'width' => $new_img_size[0],
                         'height' => $new_img_size[1]
                 );

                 return $vt_image;
         }

         // default output - without resizing
         $vt_image = array (
                 'url' => $image_src[0],
                 'width' => $image_src[1],
                 'height' => $image_src[2]
         );

         return $vt_image;
 }

 }}}

-- 
Ticket URL: <http://core.trac.wordpress.org/ticket/15311#comment:13>
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