CDN support, new developer hook upon saving crop settings

Thinking more about this. It would seem the place to do this would be in imagecrop.module, create_image_object(). Specifically, before running an imagecache_build_derivative() to start creating new derived images.

    // if we have a dst, flush the image with all the needed imagecache actions.
    if (!empty($dst)) {
      file_delete($dst);
      imagecache_build_derivative($preset['actions'], $src, $dst);
    }

Perhaps adding a hook there? I haven't thought through all of the implications of this yet, nor have I fully explored how imagecrop uses the files within its UI.

Awesome, thank you. Seems like a good place to do it on the form submit action.

I'll roll up an example implementation of the hook for renaming of the file. I should have that done within the next few days, so if you like keep this open and I'll post my code back and close it out.

Thanks for the assistance and support!

OK, here's some documentation - perhaps for a DEVELOPER.txt?

Imagecrop makes available the following developer hooks:

==============

hook_imagecrop_settings_update($form_values) 

This hook is run during the imageoffsets_form_submit. IE, when the imagecrop form is being saved with the new preset values. The new updated crop values are saved to the database, the existing preset is cleared, then this hook is run.

This is especially useful for scenarios where you may want to do things like rename the imagecaceh file. That use case is applicable to CDNs, where the previous filename may be cached upstream and there is a need to either expire the cached file or perhaps rename the file to prompt a CDN to re-cache it.

This is not perfect, but here's an implementation of the hook that uses filefield_paths to rename the file. In my case, my filefield_paths token inserts that custom timestamp/md5 hash so the files always get different names.

/**
 * Implementation of hook_imagecrop_settings_update()
 */
function mymodule_imagecrop_settings_update($form_values) {
  if (is_numeric($form_values['fid'])) {
    // Load up the file
    $file = field_file_load($form_values['fid']);
    // We don't get NID in the $form_values, so we need to go look up what node this belongs to
    $references = array_keys(filefield_get_file_references($file, $form_values['field']));
    // Not sure what to do if more than one node comes back, or even how that would happen so I lock this at 1. Works for me
    if (count($references) == 1) {
      $node = node_load($references[0]); 
      // This forcibly sets a filefield_paths variable to ensure the file is renamed. 
      $resetvar = "ffp_" . $node->type . "_" . $form_values['field'];
      variable_set($resetvar, TRUE);
      // Rename the file with filefield_paths
      filefield_paths_node_update($node);
      // Kill the var again so other renames don't happen for other parts of the site
      variable_del($resetvar);
    }
  }
}

I declare this fixed! :) Thanks for the hook, very helpful.

OK it's not really fixed :(

I think the hook is in the wrong place. It works in the form submit action for the final photo, but it does not work when the user is actively resizing/rescaling images in the viewport. IE, I select a dropdown and choose a different size for the photo but before I save it. When that happens, the js callback hits imagecrop_docrop() only and not the submit. The end result is that the image inside of the viewport is not updated because the CDN is still serving the same cached name of the image.

If the hook is in imagecrop_docrop() that would seem to fix it, because it would handle both the submit as well as any realtime changes by the user when they fiddle with the scale dropdown.

Here's a patch for 6.x. It moves the hook to imagecrop_docrop, which now seems to work for me - at least so far.

Yup, that works for me. Here's a revised version of my hook implementation:

/**
 * Implementation of hook_imagecrop_settings_update()
 *   This hook is called on the form submit action for the imagecrop module. When the user selects a new
 *   crop, this hook provides a bunch of values related to the new crop. We need to call this to
 *   change the master image filename. This effectively 'clears' the upstream CDN image cache. Since
 *   the name of the image changed, all imagecache presets are regenerated and re-cached. This ensures
 *   that the changed preset is shown immediately to the user.
 */
function mymodule_imagecrop_settings_update($fid, $presetid, $module, $field, $node_type) {
  if (is_numeric($fid)) {
    $file = field_file_load($fid);
    $references = array_keys(filefield_get_file_references($file, $field));
    if (count($references) == 1) {
      $node = node_load($references[0]);
      $resetvar = "ffp_" . $node_type . "_" . $field;
      variable_set($resetvar, TRUE);
      filefield_paths_node_update($node);
      variable_del($resetvar);
    }
  }
}

Still working this...

Right now, with the above patch, everything works properly when you are in the crop popup box. The image is renamed, imagecache created, cached at the CDN, boom looks good. The problem is that when the actual node is saved/submitted (not the crop - the actual node save), I have another function which triggers a regeneration of the image by using imagecache_generate_image(). The issue with this is that the image is NOT created using imagecrop, or at least it doesn't work properly. It generates an image of the correct size, with no cropping or scaling applied. Hmm.