Change /api/v1/items/aggregations filtering logic

CHANGELOG.md

@@ -5,6 +5,9 @@ All notable changes to this project will be documented in this file[^1].
 ### Added
 - images:generate-ratios command
 
+### Changed
+- behaviour for /api/v1/items/aggregations so that facet doesn't filter itself
+
 ## [2.78.0] - 2023-07-21
 ### Added
 - images->deep_zoom_url to /api/v2/items/{id}

app/Http/Controllers/Api/V1/ItemController.php

@@ -5,11 +5,10 @@
 use App\Elasticsearch\Repositories\ItemRepository;
 use App\Http\Controllers\Controller;
 use App\Item;
-use ElasticAdapter\Search\Aggregation;
-use ElasticAdapter\Search\Bucket;
 use ElasticScoutDriverPlus\Exceptions\QueryBuilderException;
 use ElasticScoutDriverPlus\Support\Query;
 use Illuminate\Http\Request;
+use Illuminate\Support\Arr;
 use Primal\Color\Parser as ColorParser;
 
 class ItemController extends Controller
@@ -101,55 +100,76 @@ public function aggregations(Request $request)
         $size = (int) $request->get('size', 1);
         $q = (string) $request->get('q');
 
-        try {
-            $query = $this->createQueryBuilder($q, $filter)->buildQuery();
-        } catch (QueryBuilderException $e) {
-            $query = ['match_all' => new \stdClass()];
-        }
-
-        $searchRequest = Item::searchQuery($query);
+        $aggregationsQuery = [];
 
         foreach ($terms as $agg => $field) {
-            $searchRequest->aggregate($agg, [
-                'terms' => [
-                    'field' => $field,
-                    'size' => $size,
-                ],
-            ]);
+            $aggregationsQuery[$agg]['aggregations']['filtered']['terms'] = [
+                'field' => $field,
+                'size' => $size,
+            ];
         }
 
         foreach ($min as $agg => $field) {
-            $searchRequest->aggregate($agg, [
-                'min' => [
-                    'field' => $field,
-                ],
-            ]);
+            $aggregationsQuery[$agg]['aggregations']['filtered']['min'] = [
+                'field' => $field,
+            ];
         }
 
         foreach ($max as $agg => $field) {
-            $searchRequest->aggregate($agg, [
-                'max' => [
-                    'field' => $field,
+            $aggregationsQuery[$agg]['aggregations']['filtered']['max'] = [
+                'field' => $field,
+            ];
+        }
+
+        // Add filter terms to each aggregation
+        // Based on https://madewithlove.com/blog/faceted-search-using-elasticsearch/
+        foreach (array_keys($aggregationsQuery) as $term) {
+            $aggregationsQuery[$term]['filter'] = $this->createQueryBuilder(
+                $q,
+                Arr::except($filter, $term)
+            )->buildQuery();
+        }
+
+        $searchRequest = Item::searchQuery()
+            ->size(0)
+            ->aggregateRaw([
+                'all_items' => [
+                    'global' => (object) [],
+                    'aggregations' => (object) $aggregationsQuery,
                 ],
             ]);
-        }
 
-        $searchResult = $searchRequest->execute();
-        return response()->json(
-            $searchResult->aggregations()->map(function (Aggregation $aggregation) {
-                $raw = $aggregation->raw();
-                if (array_key_exists('value', $raw)) {
-                    return $raw['value'];
+        $searchResponse = collect(
+            Arr::get($searchRequest->execute()->raw(), 'aggregations.all_items')
+        )
+            ->only(array_keys($aggregationsQuery))
+            ->map(function (array $aggregation) {
+                if (Arr::has($aggregation, 'filtered.value')) {
+                    return Arr::get($aggregation, 'filtered.value');
                 }
 
-                return $aggregation->buckets()->map(function (Bucket $bucket) {
-                    return [
-                        'value' => $bucket->key(),
-                        'count' => $bucket->docCount(),
-                    ];
-                });
-            })
-        );
+                return collect(Arr::get($aggregation, 'filtered.buckets'))->map(
+                    fn(array $bucket) => [
+                        'value' => $bucket['key'],
+                        'count' => $bucket['doc_count'],
+                    ]
+                );
+            });
+
+        // Ensure filtered (i.e. selected) terms are included in the response
+        foreach ($filter as $term => $value) {
+            if (!Arr::has($terms, $term)) {
+                continue;
+            }
+
+            foreach (array_reverse(Arr::wrap($value)) as $value) {
+                if (!$searchResponse[$term]->contains('value', $value)) {
+                    $searchResponse[$term]->prepend(['value' => $value, 'count' => 0])->pop();
+                }
+            }
+        }
+
+        return $searchResponse;
     }
 
     public function detail(Request $request, $id)
@@ -176,6 +196,10 @@ public function detail(Request $request, $id)
 
     protected function createQueryBuilder($q, $filter)
     {
+        if (empty($q) && empty($filter)) {
+            return Query::matchAll();
+        }
+
         $builder = Query::bool();
 
         if ($q) {

routes/api.php

@@ -27,7 +27,9 @@
     ->name('api.v1.')
     ->group(function () {
         Route::get('items', [V1ItemController::class, 'index'])->name('items.index');
-        Route::get('items/aggregations', [V1ItemController::class, 'aggregations']);
+        Route::get('items/aggregations', [V1ItemController::class, 'aggregations'])->name(
+            'items.aggregations'
+        );
         Route::get('items/{id}', [V1ItemController::class, 'detail'])->name('items.show');
     });
 

tests/Feature/Api/V1/ItemsAggregationsTest.php

@@ -0,0 +1,123 @@
+<?php
+
+namespace Tests\Feature\Api\V1;
+
+use App\Elasticsearch\Repositories\ItemRepository;
+use App\Item;
+use Illuminate\Foundation\Testing\RefreshDatabase;
+use Tests\RecreateSearchIndex;
+use Tests\TestCase;
+
+class ItemsAggregationsTest extends TestCase
+{
+    use RefreshDatabase;
+    use RecreateSearchIndex;
+
+    private $initialized = false;
+
+    public function setUp(): void
+    {
+        parent::setUp();
+
+        if ($this->initialized) {
+            return;
+        }
+
+        Item::factory()->createMany([
+            [
+                'author' => 'Galanda, Mikuláš',
+                'topic' => 'spring',
+                'date_earliest' => 1000,
+            ],
+            [
+                'author' => 'Wouwerman, Philips',
+                'topic' => 'summer',
+                'date_earliest' => 2000,
+            ],
+        ]);
+
+        app(ItemRepository::class)->refreshIndex();
+        $this->initialized = true;
+    }
+
+    private function getAggregations(array $params = [])
+    {
+        $defaultParams = ['size' => 10];
+        $url = route('api.v1.items.aggregations', array_merge($defaultParams, $params));
+        return $this->getJson($url);
+    }
+
+    public function test_shows_nothing_by_default()
+    {
+        $this->getAggregations()->assertExactJson([]);
+    }
+
+    public function test_shows_terms()
+    {
+        $this->getAggregations(['terms' => ['my_author' => 'author']])->assertExactJson([
+            'my_author' => [
+                ['value' => 'Galanda, Mikuláš', 'count' => 1],
+                ['value' => 'Wouwerman, Philips', 'count' => 1],
+            ],
+        ]);
+    }
+
+    public function test_filters_results()
+    {
+        $this->getAggregations([
+            'filter' => ['topic' => ['summer']],
+            'terms' => ['author' => 'author'],
+        ])->assertExactJson([
+            'author' => [['value' => 'Wouwerman, Philips', 'count' => 1]],
+        ]);
+    }
+    public function test_filtered_faced_does_not_affect_itself()
+    {
+        $this->getAggregations([
+            'filter' => ['topic' => ['summer']],
+            'terms' => ['topic' => 'topic'],
+        ])->assertExactJson([
+            'topic' => [['value' => 'spring', 'count' => 1], ['value' => 'summer', 'count' => 1]],
+        ]);
+    }
+
+    public function test_gets_min_and_max()
+    {
+        $this->getAggregations([
+            'min' => ['date_earliest_min' => 'date_earliest'],
+            'max' => ['date_earliest_max' => 'date_earliest'],
+        ])->assertExactJson([
+            'date_earliest_min' => 1000,
+            'date_earliest_max' => 2000,
+        ]);
+    }
+
+    public function test_size_limits_number_of_buckets()
+    {
+        $this->assertCount(
+            1,
+            $this->getAggregations([
+                'size' => null, // reset to default
+                'terms' => ['topic' => 'topic'],
+            ])['topic']
+        );
+
+        $this->assertCount(
+            2,
+            $this->getAggregations([
+                'terms' => ['topic' => 'topic'],
+                'size' => 2,
+            ])['topic']
+        );
+    }
+
+    public function test_selected_facet_value_is_always_present()
+    {
+        $this->getAggregations([
+            'filter' => ['topic' => ['spring'], 'author' => ['Wouwerman, Philips']],
+            'terms' => ['topic' => 'topic', 'author' => 'author'],
+        ])
+            ->assertJsonFragment(['value' => 'spring', 'count' => 0])
+            ->assertJsonFragment(['value' => 'Wouwerman, Philips', 'count' => 0]);
+    }
+}