Element API access param in transformer

Question

Each of my entries has multiple categories (e.g. series, disciplines, and stages). I can get a list of elements related to a single category but I'd also like to get the category information as well (title, summary etc). Ideally, I'd like to pass the $slug to the transformer so I can grab the category from there, is that possible?

Here's my current code for an endpoint from elementapi.php

'api/series/<slug:{slug}>.json' => function($slug) {
  // get category by slug
  $series = craft()->elements->getCriteria(ElementType::Category);
  $series->group = 'series';
  $series->slug = $slug;
  $series->first();

  return [
    'elementType' => ElementType::Entry,
    'criteria' => [
      'section' => ['lessons'],
      'relatedTo' => ['targetElement' => $series]
    ],
    'transformer' => function(EntryModel $entry) {
      return structureEntry($entry);
    }
  ];
},

/*-------------------------------------------*/

function structureEntry($entry) {
  return [
    'id' => (int)$entry->id,
    'title' => $entry->title,
    'slug' => $entry->slug,
    'summary' => $entry->summary ? $entry->summary : null,
    'featuredImage' => $entry->featuredImage->first() ? getImageSizes($entry->featuredImage->first()) : null,
    'body' => $entry->body ? (string)$entry->body : null,
    'series' => $entry->series ? getCategoryData($entry->series) : null,
    'stage' => $entry->stage ? getCategoryData($entry->stage) : null,
    'disciplines' => $entry->discipline ? getCategoryData($entry->discipline) : null
  ];
}

function getCategoryData($categories) {
  $cats = array();

  for($i = 0; $i < count($categories); $i++) {
    $cats[$i] = [
      'id' => (int)$categories[$i]->id,
      'title' => $categories[$i]->title,
      'slug' => $categories[$i]->slug,
      'summary' => $categories[$i]->summary
    ];
  }

  return $cats;
}

Ideally, I'd like to do something like this:

'api/series/<slug:{slug}>.json' => function($slug) {
  // get category by slug
  $series = craft()->elements->getCriteria(ElementType::Category);
  $series->group = 'series';
  $series->slug = $slug;
  $series->first();

  return [
    'elementType' => ElementType::Entry,
    'criteria' => [
      'section' => ['lessons'],
      'relatedTo' => ['targetElement' => $series]
    ],
    'transformer' => function(EntryModel $entry) {

      $category = craft()->elements->getCriteria(ElementType::Category);
      $category->group = 'series';
      $category->slug = $slug;
      $category->first();

      return array_merge(structureEntry($entry), structureCategory($category));
    }
  ];
},

Any help would be appreciated, thanks!

Answer 1

I managed to get access to the slug in the transformer function by using use. I'm not sure if it's the correct way but it works for now.

'api/series/<slug:{slug}>.json' => function($slug) {
  // get category by slug
  $category = craft()->elements->getCriteria(ElementType::Category);
  $category->group = 'series';
  $category->slug = $slug;
  $category->first();

  return [
    'elementType' => ElementType::Entry,
    'criteria' => [
      'section' => ['lessons'],
      'relatedTo' => ['targetElement' => $series]
    ],
    'transformer' => function(EntryModel $entry) use ($category) {

      $firstCategory = $category->first();

      $cat = [
        'id' => $firstCategory->id,
        'slug' => $firstCategory->slug,
        'title' => $firstCategory->title
      ];

      return array_merge(structureEntry($entry), structureCategory($cat));
    }
  ];
}