Doctrine\ODM\MongoDB\Mapping\Driver\YamlDriver::addFieldMapping PHP Метод

    private function addFieldMapping(ClassMetadataInfo $class, $mapping)
    {
        if (isset($mapping['name'])) {
            $name = $mapping['name'];
        } elseif (isset($mapping['fieldName'])) {
            $name = $mapping['fieldName'];
        } else {
            throw new \InvalidArgumentException('Cannot infer a MongoDB name from the mapping');
        }
        $class->mapField($mapping);
        if (!(isset($mapping['index']) || isset($mapping['unique']) || isset($mapping['sparse']))) {
            return;
        }
        // Multiple index specifications in one field mapping is ambiguous
        if ((isset($mapping['index']) && is_array($mapping['index'])) + (isset($mapping['unique']) && is_array($mapping['unique'])) + (isset($mapping['sparse']) && is_array($mapping['sparse'])) > 1) {
            throw new \InvalidArgumentException('Multiple index specifications found among index, unique, and/or sparse fields');
        }
        // Index this field if either "index", "unique", or "sparse" are set
        $keys = array($name => 'asc');
        /* The "order" option is only used in the index specification and should
         * not be passed along as an index option.
         */
        if (isset($mapping['index']['order'])) {
            $keys[$name] = $mapping['index']['order'];
            unset($mapping['index']['order']);
        } elseif (isset($mapping['unique']['order'])) {
            $keys[$name] = $mapping['unique']['order'];
            unset($mapping['unique']['order']);
        } elseif (isset($mapping['sparse']['order'])) {
            $keys[$name] = $mapping['sparse']['order'];
            unset($mapping['sparse']['order']);
        }
        /* Initialize $options from any array value among index, unique, and
         * sparse. Any boolean values for unique or sparse should be merged into
         * the options afterwards to ensure consistent parsing.
         */
        $options = array();
        $unique = null;
        $sparse = null;
        if (isset($mapping['index']) && is_array($mapping['index'])) {
            $options = $mapping['index'];
        }
        if (isset($mapping['unique'])) {
            if (is_array($mapping['unique'])) {
                $options = $mapping['unique'] + array('unique' => true);
            } else {
                $unique = (bool) $mapping['unique'];
            }
        }
        if (isset($mapping['sparse'])) {
            if (is_array($mapping['sparse'])) {
                $options = $mapping['sparse'] + array('sparse' => true);
            } else {
                $sparse = (bool) $mapping['sparse'];
            }
        }
        if (isset($unique)) {
            $options['unique'] = $unique;
        }
        if (isset($sparse)) {
            $options['sparse'] = $sparse;
        }
        $class->addIndex($keys, $options);
    }