Sokil\Mongo\Document::save PHP Method

    public function save($validate = true)
    {
        // save document
        // if document already in db and not modified - skip this method
        if (!$this->isSaveRequired()) {
            return $this;
        }
        if ($validate) {
            $this->validate();
        }
        // handle beforeSave event
        if ($this->triggerEvent('beforeSave')->isCancelled()) {
            return $this;
        }
        if ($this->isStored()) {
            if ($this->triggerEvent('beforeUpdate')->isCancelled()) {
                return $this;
            }
            // locking
            $query = array('_id' => $this->getId());
            if ($this->getOption('lock') === Definition::LOCK_OPTIMISTIC) {
                $query['__version__'] = $this->get('__version__');
                $this->getOperator()->increment('__version__');
            }
            // update
            $status = $this->collection->getMongoCollection()->update($query, $this->getOperator()->toArray());
            // check update status
            if ($status['ok'] != 1) {
                throw new \Sokil\Mongo\Exception(sprintf('Update error: %s: %s', $status['err'], $status['errmsg']));
            }
            // check if document modified due to specified lock
            if ($this->getOption('lock') === Definition::LOCK_OPTIMISTIC) {
                if ($status['n'] === 0) {
                    throw new OptimisticLockFailureException();
                }
            }
            if ($this->getOperator()->isReloadRequired()) {
                $this->refresh();
            } else {
                $this->getOperator()->reset();
            }
            $this->triggerEvent('afterUpdate');
        } else {
            if ($this->triggerEvent('beforeInsert')->isCancelled()) {
                return $this;
            }
            $document = $this->toArray();
            $this->collection->getMongoCollection()->insert($document);
            // set id
            $this->defineId($document['_id']);
            // after insert event
            $this->triggerEvent('afterInsert');
        }
        // handle afterSave event
        $this->triggerEvent('afterSave');
        $this->apply();
        return $this;
    }