Doctrine\ODM\MongoDB\Mapping\ClassMetadataInfo::setDiscriminatorField PHP Method

    public function setDiscriminatorField($discriminatorField)
    {
        if ($discriminatorField === null) {
            $this->discriminatorField = null;
            return;
        }
        // Handle array argument with name/fieldName keys for BC
        if (is_array($discriminatorField)) {
            if (isset($discriminatorField['name'])) {
                $discriminatorField = $discriminatorField['name'];
            } elseif (isset($discriminatorField['fieldName'])) {
                $discriminatorField = $discriminatorField['fieldName'];
            }
        }
        foreach ($this->fieldMappings as $fieldMapping) {
            if ($discriminatorField == $fieldMapping['name']) {
                throw MappingException::discriminatorFieldConflict($this->name, $discriminatorField);
            }
        }
        $this->discriminatorField = $discriminatorField;
    }

    /**
     * {@inheritdoc}
     */
    public function loadMetadataForClass($className, ClassMetadataInfo $class)
    {
        $element = $this->getElement($className);
        if ( ! $element) {
            return;
        }
        $element['type'] = isset($element['type']) ? $element['type'] : 'document';

        if (isset($element['db'])) {
            $class->setDatabase($element['db']);
        }
        if (isset($element['collection'])) {
            $class->setCollection($element['collection']);
        }
        if ($element['type'] == 'document') {
            if (isset($element['repositoryClass'])) {
                $class->setCustomRepositoryClass($element['repositoryClass']);
            }
        } elseif ($element['type'] === 'mappedSuperclass') {
            $class->isMappedSuperclass = true;
        } elseif ($element['type'] === 'embeddedDocument') {
            $class->isEmbeddedDocument = true;
        }
        if (isset($element['indexes'])) {
            foreach($element['indexes'] as $index) {
                $class->addIndex($index['keys'], isset($index['options']) ? $index['options'] : array());
            }
        }
        if (isset($element['inheritanceType'])) {
            $class->setInheritanceType(constant('Doctrine\ODM\MongoDB\Mapping\ClassMetadata::INHERITANCE_TYPE_' . strtoupper($element['inheritanceType'])));
        }
        if (isset($element['discriminatorField'])) {
            $discrField = $element['discriminatorField'];
            $class->setDiscriminatorField(array(
                'name' => $discrField['name'],
                'fieldName' => $discrField['fieldName']
            ));
        }
        if (isset($element['discriminatorMap'])) {
            $class->setDiscriminatorMap($element['discriminatorMap']);
        }
        if (isset($element['changeTrackingPolicy'])) {
            $class->setChangeTrackingPolicy(constant('Doctrine\ODM\MongoDB\Mapping\ClassMetadata::CHANGETRACKING_'
                    . strtoupper($element['changeTrackingPolicy'])));
        }
        if (isset($element['fields'])) {
            foreach ($element['fields'] as $fieldName => $mapping) {
                if (is_string($mapping)) {
                    $type = $mapping;
                    $mapping = array();
                    $mapping['type'] = $type;
                }
                if ( ! isset($mapping['fieldName'])) {
                    $mapping['fieldName'] = $fieldName;
                }
                if (isset($mapping['type']) && $mapping['type'] === 'collection') {
                    $mapping['strategy'] = isset($mapping['strategy']) ? $mapping['strategy'] : 'pushAll';
                }
                $this->addFieldMapping($class, $mapping);
            }
        }
        if (isset($element['embedOne'])) {
            foreach ($element['embedOne'] as $fieldName => $embed) {
                $this->addMappingFromEmbed($class, $fieldName, $embed, 'one');
            }
        }
        if (isset($element['embedMany'])) {
            foreach ($element['embedMany'] as $fieldName => $embed) {
                $this->addMappingFromEmbed($class, $fieldName, $embed, 'many');
            }
        }
        if (isset($element['referenceOne'])) {
            foreach ($element['referenceOne'] as $fieldName => $reference) {
                $this->addMappingFromReference($class, $fieldName, $reference, 'one');
            }
        }
        if (isset($element['referenceMany'])) {
            foreach ($element['referenceMany'] as $fieldName => $reference) {
                $this->addMappingFromReference($class, $fieldName, $reference, 'many');
            }
        }
        if (isset($element['lifecycleCallbacks'])) {
            foreach ($element['lifecycleCallbacks'] as $type => $methods) {
                foreach ($methods as $method) {
                    $class->addLifecycleCallback($method, constant('Doctrine\ODM\MongoDB\Events::' . $type));
                }
            }
        }
    }