Extend mapping API to allow for defaults and multiple callbacks.

Not much damage yet! I hope to look at the patch in a few days. Or is the patch just a start/incomplete?

Great! I hope to take a look at this patch next Thursday. I remember from last time, back in September last year, I had a hard time to review it.

This patch looks like it brings a lot of improvements and clean-ups. Great work!

Here is what I could find so far after looking at the code.

1. +++ b/plugins/FeedsProcessor.inc
   @@ -873,13 +951,13 @@ abstract class FeedsProcessor extends FeedsPlugin {
   -        foreach ($targets[$this->id][$target]['unique_callbacks'] as $callback) {
   -          if (is_callable($callback) && $entity_id = call_user_func_array($callback, array($source, $this->entityType(), $this->bundle(), $target, $value))) {
   +        foreach ($targets[$target]['unique_callbacks'] as $callback) {
   +          if ($entity_id = $callback($source, $this->entityType(), $this->bundle(), $target, $value)) {
   

   I think you should leave the call_user_func_array() here, because a callback can also be defined as an array if the callback points to a class method, for example:

   $callback = array('MyClass', 'myCallbackMethod');
   

   See http://php.net/manual/en/language.types.callable.php

2. +++ b/feeds_ui/feeds_ui.admin.inc
   @@ -634,12 +634,10 @@ function feeds_ui_mapping_settings_form($form, $form_state, $i, $mapping, $targe
   -    // Build the form.
   -    if (isset($target['form_callback'])) {
   -      $settings_form = call_user_func($target['form_callback'], $mapping, $target, $form, $form_state);
   -    }
   -    else {
   -      $settings_form = array();
   +    $settings_form = array();
   +
   +    foreach ($target['form_callbacks'] as $callback) {
   +      $settings_form += $callback($mapping, $target, $form, $form_state);
   
   @@ -664,13 +662,15 @@ function feeds_ui_mapping_settings_form($form, $form_state, $i, $mapping, $targe
   -    if (isset($target['summary_callback'])) {
   -      $summary = call_user_func($target['summary_callback'], $mapping, $target, $form, $form_state);
   -    }
   -    else {
   -      $summary = '';
   +    $summary = array();
   +
   +    foreach ($target['summary_callbacks'] as $callback) {
   +      $summary[] = $callback($mapping, $target, $form, $form_state);
   

   Same story here. A callback can be a class method.

3. +++ b/feeds.feeds.inc
   @@ -0,0 +1,86 @@
   +  // Filter out any incorect callbaks. Do it here so it only has to be done
   

   Typos:

   • "incorect" => "incorrect"
   • "callbaks" => "callbacks"
4. Documentation for the new hook hook_feeds_processor_targets() is missing in feeds.api.php.
5. I see targets can now have "preprocess_callbacks", but in feeds.api.php it is not documented that a target can have such a callback, what it does and what the signature for the callback is. Add an example function called my_module_preprocess_callback() and an example target to feeds.api.php.
6. For the tests, I think it would be a good idea to add a test target with two summary callbacks and two form callbacks. This way the behaviour of having multiple callbacks can be covered. Now all test targets in feeds_tests.module that have summary/form callbacks defined have only one summary/form callback.