Hi,

Doing a little further investigation, I figured out how "i.php" works with the custom derivatives.  It in fact does reverse engineer the parameters from the (for example) e260x180.

If the custom parameters were stored in the database, this whole routine could be reduced to one line of code and a few supporting routines could be removed.

Now I look further, the scope of this change is a bit larger than I anticipated.

i.php:

function parse_custom_params($tokens)
{
  if (count($tokens)<1)
    ierror('Empty array while parsing Sizing', 400);

  $crop = 0;
  $min_size = null;

  $token = array_shift($tokens);
  if ($token[0]=='s')
  {
    $size = url_to_size( substr($token,1) );
  }
  elseif ($token[0]=='e')
  {
    $crop = 1;
    $size = $min_size = url_to_size( substr($token,1) );
  }
  else
  {
    $size = url_to_size( $token );
    if (count($tokens)<2)
      ierror('Sizing arr', 400);

    $token = array_shift($tokens);
    $crop = char_to_fraction($token);

    $token = array_shift($tokens);
    $min_size = url_to_size( $token );
  }
  return new DerivativeParams( new SizingParams($size, $crop, $min_size) );
}

Figuring out how i.php works enabled me to make a shell script that will regenerate my custom images :)   I'm not saying I don't want to make the changes to piwigo, but for the moment, this will speed up my website which is running on a PCEngines alix low power board (12 watts?).

I've included my shell script in case it helps anyone else.  This is running on a Unix (OpenBSD) box with shell access to the gallery.

Save the script as "custom" in the gallery folder.  Tweak as necessary.
-------------------------------------
!/bin/sh

# Note the / on the end
where="/var/www/piwigo/galleries/"

# The path and name of this script.  For now, it's just in the gallery folder
custom=${where}custom

# Space separated list of sizes to regenerate
sizes="e260x180"

if [ ! -d $where ]; then
  echo "Unable to locate $where"
  exit 1
fi

cd $where
if [ $? -ne 0 ]; then
  echo "Unable to change directory to $where"
  exit 1
fi

# If no folder specified, then do something cool/nasty and fork a process
# for each folder in the main level of gallery.  This will HAMMER the system, but in
# the interest of expediency... :)
#
# On systems with many root folders, might run out of processes trying this.
# Should do something smarter, but it works for me :)

# If no parameters, for a process for each folder
if [ $# -eq 0 ]; then
  for dir in *; do
    if [ -d "$dir" ]; then
      echo "Forking to process $dir"
      echo "Executing ${where}custom $dir"
      ${where}custom "$dir" > /tmp/custom_out.$dir 2>&1 &
    else
      echo "Skipping non-directory $dir"
    fi
  done
  # Done forking, just exit
  exit 0
fi

# Just to make sure
if [ ! -d "$1" ]; then
  echo "Unable to locate $1"
  exit 1
fi

# Temporary working directory
mkdir /tmp/custom.$$

find "$1" \( ! -name '*.htm' -a ! -name '*.php' -a ! -name '*.html' \) -type f -print | while read file; do
  echo "Processing $file"
  dir=`dirname "$file"`
  f=`basename "$file" | awk -F. '{ print substr($0,1,index($0,".")-1)}'`
  ext=`basename "$file" | awk -F. '{ print substr($0,index($0,".")+1)}'`
  for size in $sizes; do
    cd /tmp/custom.$$
    if [ $? -ne 0 ]; then
      echo "Unable to change directory to /tmp/custom.$$"
      exit 1
    fi

    # Deal with spaces in the URL
    # TODO - This isn't working :( - but piwigo doesn't show galleries/photos with spaces,
    # so not a big deal right now.  For me, legacy of importing from gallery3
    url="https://piwigo.williamsitconsulting.com/i.php?/galleries/${dir}/${f}-cu_${size}.${ext}"
    url=`echo "$url" | sed 's/ /\&nbsp;/g'`
    echo $url
    ftp $url
    rm -f ${f}-cu_${size}.${ext}
  done
done

cd $where
rm -f /tmp/custom.$$
exit 0

Hi CalgarySteveWilliams,

I found your post when also trying to get the customderivatices script from Bootstrap Darkroom to work. (Also had the error "Trying to get property of non-object") After turning on curl errors to be logged got to know that it is caused by a malformed url. (Only cannot determine what would be wrong)
I also tried your shell script but didn't get it working right now.
Anyway did you make any progress on this matter, perhaps a plugin or something like that?
I also contacted the author of the original plugin and he directed me here since the custom derivatives is not part of the core of the theme.

Sander.