add nested model trait

Author: michalsn

src/NestedModelTrait.php

@@ -0,0 +1,142 @@
+<?php
+
+namespace Michalsn\CodeIgniterNestedModel;
+
+use CodeIgniter\Model;
+use InvalidArgumentException;
+use ReflectionObject;
+
+trait NestedModelTrait
+{
+    protected array $validRelations      = ['hasOne', 'hasMany'];
+    protected array $activeRelations     = [];
+    protected array $clausesForRelations = [];
+
+    /**
+     * Set defined relation for usage.
+     */
+    public function with(string $name, ?callable $clause = null): static
+    {
+        if (! $this->relations[$name]) {
+            throw new InvalidArgumentException(sprintf('Incorrect relation name: %s', $name));
+        }
+
+        $this->activeRelations[$name] = $this->relations[$name];
+        $this->clausesForRelations[$name] = $clause;
+
+        if (! isset($this->afterFind[0]) || $this->afterFind[0] !== 'applyRelations') {
+            array_unshift($this->afterFind, 'applyRelations');
+        }
+
+        return $this;
+    }
+
+    /**
+     * Register relations via event.
+     */
+    protected function applyRelations(array $data): array
+    {
+        if (empty($data['data'])) {
+            return $data;
+        }
+
+        foreach ($this->activeRelations as $name => $relation) {
+            if (! in_array($relation[0], $this->validRelations)) {
+                throw new InvalidArgumentException(sprintf('Incorrect relation type: %s', $relation[0]));
+            }
+            $this->applyRelation($name, $relation[0], $relation[1], $relation[2] ?? null, $relation[3] ?? null, $data);
+        }
+
+        $this->activeRelations     = [];
+        $this->clausesForRelations = [];
+
+        return $data;
+    }
+
+    /**
+     * Fire the relation.
+     */
+    protected function applyRelation(string $name, string $relationType, string $model, ?string $foreignKey, ?string $localKey, &$data)
+    {
+        $modelInstance = model($model);
+
+        $foreignKey = $foreignKey ?? $this->getRelationForeignKey($modelInstance);
+        $localKey   = $localKey ?? $this->primaryKey;
+
+        $ids = $this->getRelationIds($data, $localKey);
+
+        $modelInstance->whereIn($foreignKey, $ids);
+
+        if (! empty($this->clausesForRelations[$name]) && is_callable($this->clausesForRelations[$name])) {
+            $this->clausesForRelations[$name]();
+        }
+
+        if ($data['singleton']) {
+            if ($relationType === 'hasOne') {
+                $results = $modelInstance->first();
+            } else {
+                $results = $modelInstance->findAll();
+            }
+
+            if ($this->tempReturnType === 'array') {
+                $data['data'][$name] = $results;
+            } else {
+                $data['data']->{$name} = $results;
+            }
+        } else {
+            $results = $modelInstance->findAll();
+
+            $relatedData = [];
+
+            if ($relationType === 'hasOne') {
+                foreach ($results as $row) {
+                    $relatedData[$this->tempReturnType === 'array' ? $row[$foreignKey] : $row->{$foreignKey}] = $row;
+                }
+            } else {
+                foreach ($results as $row) {
+                    $relatedData[$this->tempReturnType === 'array' ? $row[$foreignKey] : $row->{$foreignKey}][] = $row;
+                }
+            }
+
+            foreach ($data['data'] as &$row) {
+                if ($this->tempReturnType === 'array') {
+                    $row[$name] = $relatedData[$row[$localKey]] ?? [];
+                } else {
+                    $row->{$name} = $relatedData[$row->{$localKey}] ?? [];
+                }
+            }
+
+            $relatedData = null;
+        }
+    }
+
+    /**
+     * Get IDs required by relation.
+     */
+    protected function getRelationIds(array $data, ?string $localKey): array
+    {
+        $key = $localKey ?? $this->primaryKey;
+
+        if ($data['singleton']) {
+            return $this->tempReturnType === 'array'
+                ? [$data['data'][$key]]
+                : [$data['data']->{$key}];
+        }
+
+        return array_column($data['data'], $key);
+    }
+
+    /**
+     * Guess foreign key.
+     */
+    protected function getRelationForeignKey(Model $model): string
+    {
+        helper('inflector');
+
+        $refObj  = new ReflectionObject($model);
+        $refProp = $refObj->getProperty('primaryKey');
+        $refProp->setAccessible(true);
+
+        return sprintf('%s_%s', singular($this->table), $refProp->getValue($model));
+    }
+}