Webiny\Component\Entity\AbstractEntity::delete PHP Method

    public function delete()
    {
        /**
         * Check for many2many attributes and make sure related Entity has a corresponding many2many attribute defined.
         * If not - deleting is not allowed.
         */
        /* @var $attr Many2ManyAttribute */
        $thisClass = get_class($this);
        foreach ($this->getAttributes() as $attrName => $attr) {
            if ($this->isInstanceOf($attr, AttributeType::MANY2MANY)) {
                $foundMatch = false;
                $relatedClass = $attr->getEntity();
                $relatedEntity = new $relatedClass();
                /* @var $relAttr Many2ManyAttribute */
                foreach ($relatedEntity->getAttributes() as $relAttr) {
                    if ($this->isInstanceOf($relAttr, AttributeType::MANY2MANY) && $this->isInstanceOf($this, $relAttr->getEntity())) {
                        $foundMatch = true;
                    }
                }
                if (!$foundMatch) {
                    throw new EntityException(EntityException::NO_MATCHING_MANY2MANY_ATTRIBUTE_FOUND, [$thisClass, $relatedClass, $attrName]);
                }
            }
        }
        /**
         * First check all one2many records to see if deletion is restricted
         */
        $one2manyDelete = [];
        $many2oneDelete = [];
        $many2manyDelete = [];
        foreach ($this->getAttributes() as $key => $attr) {
            if ($this->isInstanceOf($attr, AttributeType::ONE2MANY)) {
                /* @var $attr One2ManyAttribute */
                if ($attr->getOnDelete() == 'restrict' && $this->getAttribute($key)->getValue()->count() > 0) {
                    throw new EntityException(EntityException::ENTITY_DELETION_RESTRICTED, [$key]);
                }
                $one2manyDelete[] = $attr;
            }
            if ($this->isInstanceOf($attr, AttributeType::MANY2ONE) && $attr->getOnDelete() === 'cascade') {
                $many2oneDelete[] = $attr;
            }
            if ($this->isInstanceOf($attr, AttributeType::MANY2MANY)) {
                $many2manyDelete[] = $attr;
            }
        }
        /**
         * Delete one2many records
         */
        foreach ($one2manyDelete as $attr) {
            foreach ($attr->getValue() as $item) {
                $item->delete();
            }
        }
        /**
         * Delete many2many records
         */
        foreach ($many2manyDelete as $attr) {
            $attr->unlinkAll();
        }
        /**
         * Delete many2one records that are set to 'cascade'
         */
        foreach ($many2oneDelete as $attr) {
            $value = $attr->getValue();
            if ($value && $value instanceof AbstractEntity) {
                $value->delete();
            }
        }
        /**
         * Delete $this
         */
        $this->entity()->getDatabase()->delete(static::$entityCollection, ['_id' => $this->entity()->getDatabase()->id($this->id)]);
        static::entity()->remove($this);
        return true;
    }