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lib/pkp/classes/category/Collector.php

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+<?php
+/**
+ * @file classes/category/Collector.php
+ *
+ * Copyright (c) 2014-2021 Simon Fraser University
+ * Copyright (c) 2000-2021 John Willinsky
+ * Distributed under the GNU GPL v3. For full terms see the file docs/COPYING.
+ *
+ * @class Collector
+ *
+ * @brief A helper class to configure a Query Builder to get a collection of categories
+ */
+
+namespace PKP\category;
+
+use Illuminate\Database\Query\Builder;
+use Illuminate\Support\Collection;
+use Illuminate\Support\Facades\DB;
+use Illuminate\Support\LazyCollection;
+use PKP\core\interfaces\CollectorInterface;
+use PKP\plugins\Hook;
+
+/**
+ * @template T of Category
+ */
+class Collector implements CollectorInterface
+{
+    public DAO $dao;
+    public ?array $contextIds = null;
+    public ?array $parentIds = null;
+    public ?array $paths = null;
+    public ?array $publicationIds = null;
+    public ?int $count = null;
+    public ?int $offset = null;
+
+    public function __construct(DAO $dao)
+    {
+        $this->dao = $dao;
+    }
+
+    public function getCount(): int
+    {
+        return $this->dao->getCount($this);
+    }
+
+    /**
+     * @return Collection<int,int>
+     */
+    public function getIds(): Collection
+    {
+        return $this->dao->getIds($this);
+    }
+
+    /**
+     * @copydoc DAO::getMany()
+     * @return LazyCollection<int,T>
+     */
+    public function getMany(): LazyCollection
+    {
+        return $this->dao->getMany($this);
+    }
+
+    /**
+     * Filter categories by one or more contexts
+     */
+    public function filterByContextIds(?array $contextIds): self
+    {
+        $this->contextIds = $contextIds;
+        return $this;
+    }
+
+    /**
+     * Filter categories by one or more parent category IDs
+     */
+    public function filterByParentIds(?array $parentIds): self
+    {
+        $this->parentIds = $parentIds;
+        return $this;
+    }
+
+    /**
+     * Filter categories by one or more publication IDs
+     */
+    public function filterByPublicationIds(?array $publicationIds): self
+    {
+        $this->publicationIds = $publicationIds;
+        return $this;
+    }
+
+    /**
+     * Filter categories by one or more paths
+     */
+    public function filterByPaths(?array $paths): self
+    {
+        $this->paths = $paths;
+        return $this;
+    }
+
+    /**
+     * Limit the number of objects retrieved
+     */
+    public function limit(?int $count): self
+    {
+        $this->count = $count;
+        return $this;
+    }
+
+    /**
+     * Offset the number of objects retrieved, for example to
+     * retrieve the second page of contents
+     */
+    public function offset(?int $offset): self
+    {
+        $this->offset = $offset;
+        return $this;
+    }
+
+    /**
+     * @copydoc CollectorInterface::getQueryBuilder()
+     */
+    public function getQueryBuilder(): Builder
+    {
+        $qb = DB::table($this->dao->table . ' as c')
+            ->leftJoin('categories AS pc', 'c.parent_id', '=', 'pc.category_id')
+            ->select(['c.*']);
+
+        $qb->when($this->contextIds !== null, function ($query) {
+            $query->whereIn('c.context_id', $this->contextIds);
+        });
+
+        $qb->when($this->paths !== null, function ($query) {
+            $query->whereIn('c.path', $this->paths);
+        });
+
+        $qb->when($this->publicationIds !== null, function ($query) {
+            $query->whereIn('c.category_id', function ($query) {
+                $query->select('category_id')->from('publication_categories')->whereIn('publication_id', $this->publicationIds);
+            });
+        });
+
+        $qb->when($this->parentIds !== null, function ($query) {
+            // parentIds may contain mixed values and nulls; make sure the mix translates into the query accurately
+            $nonNullParentIds = array_filter($this->parentIds);
+            if (count($nonNullParentIds)) {
+                $query->whereIn('c.parent_id', array_filter($this->parentIds));
+            }
+            if (in_array(null, $this->parentIds)) {
+                if (count($nonNullParentIds)) {
+                    $query->orWhereNull('c.parent_id');
+                } else {
+                    $query->whereNull('c.parent_id');
+                }
+            }
+        });
+
+        $qb->orderBy(DB::raw('(COALESCE((pc.seq * 8192) + pc.category_id, 0) * 8192) + CASE WHEN pc.category_id IS NULL THEN 8192 * ((c.seq * 8192) + c.category_id) ELSE c.seq END'));
+
+        if (isset($this->count)) {
+            $qb->limit($this->count);
+        }
+
+        if (isset($this->offset)) {
+            $qb->offset($this->offset);
+        }
+
+        Hook::call('Category::Collector', [&$qb, $this]);
+
+        return $qb;
+    }
+}