Extrae entidades con ML Kit en iOS

Para analizar un fragmento de texto y extraer las entidades que contiene, invoca la API de extracción de entidades del ML Kit. Para ello, pasa el texto directamente a su método annotateText:completion:. También es posible pasar un objeto EntityExtractionParams opcional que contenga otras opciones de configuración, como una hora de referencia, una zona horaria o un filtro para limitar la búsqueda de un subconjunto de tipos de entidades. La API muestra una lista de objetos EntityAnnotation que contienen información sobre cada entidad.

Los recursos del detector base de extracción de entidades se vinculan de forma estática durante el tiempo de ejecución de la app. Agregan aproximadamente 10.7 MB a tu app.

Probar

Antes de comenzar

  1. Incluye las siguientes bibliotecas del ML Kit en el Podfile:

    pod 'GoogleMLKit/EntityExtraction', '3.2.0'
    
  2. Después de instalar o actualizar los Pods de tu proyecto, abre el proyecto de Xcode con su .xcworkspace. El ML Kit es compatible con Xcode 13.2.1 o versiones posteriores.

Extrae entidades de texto

Para extraer entidades del texto, primero crea un objeto EntityExtractorOptions especificando el idioma y úsalo para crear una instancia de EntityExtractor:

Swift

// Note: You can specify any of the 15 languages entity extraction supports here. 
let options = EntityExtractorOptions(modelIdentifier: 
                                    EntityExtractionModelIdentifier.english)
let entityExtractor = EntityExtractor.entityExtractor(options: options)

Objective‑C

// Note: You can specify any of the 15 languages entity extraction supports here. 
MLKEntityExtractorOptions *options = 
    [[MLKEntityExtractorOptions alloc] 
        initWithModelIdentifier:MLKEntityExtractionModelIdentifierEnglish];

MLKEntityExtractor *entityExtractor = 
    [MLKEntityExtractor entityExtractorWithOptions:options];

Luego, asegúrate de que se descargue el modelo de idioma requerido en el dispositivo:

Swift

entityExtractor.downloadModelIfNeeded(completion: {
  // If the error is nil, the download completed successfully.
})

Objective‑C

[entityExtractor downloadModelIfNeededWithCompletion:^(NSError *_Nullable error) {
    // If the error is nil, the download completed successfully.
}];

Una vez que se descargue el modelo, pasa una cadena y un MLKEntityExtractionParams opcional al método annotate.

Swift

// The EntityExtractionParams parameter is optional. Only instantiate and
// configure one if you need to customize one or more of its params.
var params = EntityExtractionParams()
// The params object contains the following properties which can be customized on
// each annotateText: call. Please see the class's documentation for a more
// detailed description of what each property represents.
params.referenceTime = Date();
params.referenceTimeZone = TimeZone(identifier: "GMT");
params.preferredLocale = Locale(identifier: "en-US");
params.typesFilter = Set([EntityType.address, EntityType.dateTime])

extractor.annotateText(
    text.string,
    params: params,
    completion: {
      result, error in
      // If the error is nil, the annotation completed successfully and any results 
      // will be contained in the `result` array.
    }
)

Objective‑C

// The MLKEntityExtractionParams property is optional. Only instantiate and
// configure one if you need to customize one or more of its params.
MLKEntityExtractionParams *params = [[MLKEntityExtractionParams alloc] init];
// The params object contains the following properties which can be customized on
// each annotateText: call. Please see the class's documentation for a fuller 
// description of what each property represents.
params.referenceTime = [NSDate date];
params.referenceTimeZone = [NSTimeZone timeZoneWithAbbreviation:@"GMT"];
params.preferredLocale = [NSLocale localWithLocaleIdentifier:@"en-US"];
params.typesFilter = 
    [NSSet setWithObjects:MLKEntityExtractionEntityTypeAddress, 
                          MLKEntityExtractionEntityTypeDateTime, nil];

[extractor annotateText:text.string
             withParams:params
             completion:^(NSArray *_Nullable result, NSError *_Nullable error) {
  // If the error is nil, the annotation completed successfully and any results 
  // will be contained in the `result` array.
}

Aplica un bucle a los resultados de la anotación para recuperar información sobre las entidades reconocidas.

Swift

// let annotations be the Array! returned from EntityExtractor
for annotation in annotations {
  let entities = annotation.entities
  for entity in entities {
    switch entity.entityType {
      case EntityType.dateTime:
        guard let dateTimeEntity = entity.dateTimeEntity else {
          print("This field should be populated.")
          return
        }
        print("Granularity: %d", dateTimeEntity.dateTimeGranularity)
        print("DateTime: %@", dateTimeEntity.dateTime)
      case EntityType.flightNumber:
        guard let flightNumberEntity = entity.flightNumberEntity else {
          print("This field should be populated.")
          return
        }
        print("Airline Code: %@", flightNumberEntity.airlineCode)
        print("Flight number: %@", flightNumberEntity.flightNumber)
      case EntityType.money:
        guard let moneyEntity = entity.moneyEntity else {
          print("This field should be populated.")
          return
        }
        print("Currency: %@", moneyEntity.integerPart)
        print("Integer Part: %d", moneyEntity.integerPart)
        print("Fractional Part: %d", moneyEntity.fractionalPart)
      // Add additional cases as needed.
      default:
        print("Entity: %@", entity);
    }
  }
}

Objective‑C

NSArray *annotations; // Returned from EntityExtractor

for (MLKEntityAnnotation *annotation in annotations) {
            NSArray *entities = annotation.entities;
            NSLog(@"Range: [%d, %d)", (int)annotation.range.location, (int)(annotation.range.location + annotation.range.length));
            for (MLKEntity *entity in entities) {
              if ([entity.entityType isEqualToString:MLKEntityExtractionEntityTypeDateTime]) {
                MLKDateTimeEntity *dateTimeEntity = entity.dateTimeEntity;
                NSLog(@"Granularity: %d", (int)dateTimeEntity.dateTimeGranularity);
                NSLog(@"DateTime: %@", dateTimeEntity.dateTime);
                break;
              } else if ([entity.entityType isEqualToString:MLKEntityExtractionEntityTypeFlightNumber]) {
                MLKFlightNumberEntity *flightNumberEntity = entity.flightNumberEntity;
                NSLog(@"Airline Code: %@", flightNumberEntity.airlineCode);
                NSLog(@"Flight number: %@", flightNumberEntity.flightNumber);
                break;
              } else if ([entity.entityType isEqualToString:MLKEntityExtractionEntityTypeMoney]) {
                MLKMoneyEntity *moneyEntity = entity.moneyEntity;
                NSLog(@"Currency: %@", moneyEntity.unnormalizedCurrency);
                NSLog(@"Integer Part: %d", (int)moneyEntity.integerPart);
                NSLog(@"Fractional Part: %d", (int)moneyEntity.fractionalPart);
                break;
              } else {
                // Add additional cases as needed.
                NSLog(@"Entity: %@", entity);
              }
            }