Craft\NeoService::saveFieldValue PHP Method

    public function saveFieldValue(NeoFieldType $fieldType)
    {
        $owner = $fieldType->element;
        $field = $fieldType->model;
        $blocks = $owner->getContent()->getAttribute($field->handle);
        if ($blocks === null) {
            return;
        }
        $structure = new StructureModel();
        // $structure->maxLevels = ...->maxLevels; // This might be useful somebody. Keeping it around as a reminder.
        if (!is_array($blocks)) {
            $blocks = [];
        }
        $transaction = $this->beginTransaction();
        try {
            // Make sure that the blocks for this field/owner respect the field's translation setting
            $this->_applyFieldTranslationSetting($owner, $field, $blocks);
            $this->saveStructure($structure, $fieldType);
            // Build the block structure by mapping block sort orders and levels to parent/child relationships
            $blockIds = [];
            $parentStack = [];
            foreach ($blocks as $block) {
                $block->ownerId = $owner->id;
                $block->ownerLocale = $this->_getFieldLocale($fieldType);
                // Remove parent blocks until either empty or a parent block is only one level below this one (meaning
                // it'll be the parent of this block)
                while (!empty($parentStack) && $block->level <= $parentStack[count($parentStack) - 1]->level) {
                    array_pop($parentStack);
                }
                $this->saveBlock($block, false);
                // If there are no blocks in our stack, it must be a root level block
                if (empty($parentStack)) {
                    craft()->structures->appendToRoot($structure->id, $block);
                } else {
                    $parentBlock = $parentStack[count($parentStack) - 1];
                    craft()->structures->append($structure->id, $block, $parentBlock);
                }
                // The current block may potentially be a parent block as well, so save it to the stack
                array_push($parentStack, $block);
                $blockIds[] = $block->id;
            }
            // Get the IDs of blocks that are row deleted
            $deletedBlockConditions = ['and', 'ownerId = :ownerId', 'fieldId = :fieldId', ['not in', 'id', $blockIds]];
            $deletedBlockParams = [':ownerId' => $owner->id, ':fieldId' => $field->id];
            if ($field->translatable) {
                $deletedBlockConditions[] = 'ownerLocale  = :ownerLocale';
                $deletedBlockParams[':ownerLocale'] = $owner->locale;
            }
            $deletedBlockIds = craft()->db->createCommand()->select('id')->from('neoblocks')->where($deletedBlockConditions, $deletedBlockParams)->queryColumn();
            $this->deleteBlockById($deletedBlockIds);
            $this->commitTransaction($transaction);
        } catch (\Exception $e) {
            $this->rollbackTransaction($transaction);
            throw $e;
        }
    }