Migrating for iOS

Prerequisites

Before you start to migrate your code, be sure you meet these requirements:

ML Kit supports Xcode 13.2.1 or greater.
ML Kit supports iOS version 15.5 or greater.
ML Kit does not support 32-bit architectures (i386 and armv7). ML Kit does support 64-bit architectures (x86_64 and arm64).
The ML Kit library is only provided as cocoapods. You can't mix frameworks and cocoapods, so in order to use this library you need to first migrate to use cocoapods.

Update Cocoapods

Update the dependencies for the ML Kit iOS cocoapods in your app’s Podfile:

API	Old pod name(s)	New pod name(s)
Barcode scanning	Firebase/MLVision Firebase/MLVisionBarcodeModel	GoogleMLKit/BarcodeScanning
Face detection	Firebase/MLVision Firebase/MLVisionFaceModel	GoogleMLKit/FaceDetection
Image labeling	Firebase/MLVision Firebase/MLVisionLabelModel	GoogleMLKit/ImageLabeling
Object detection and tracking	Firebase/MLVisionObjectDetection	GoogleMLKit/ObjectDetection
Text recognition	Firebase/MLVision Firebase/MLVisionTextModel	GoogleMLKit/TextRecognition
AutoML image labeling (bundled model)	Firebase/MLVisionAutoML	GoogleMLKit/ImageLabelingCustom
AutoML image labeling (model download from Firebase)	Firebase/MLVisionAutoML	GoogleMLKit/ImageLabelingCustom GoogleMLKit/LinkFirebase
Language ID	Firebase/MLNaturalLanguage Firebase/MLNLLanguageID	GoogleMLKit/LanguageID
Smart reply	Firebase/MLNaturalLanguage Firebase/MLNLSmartReply	GoogleMLKit/SmartReply
Translate	Firebase/MLNaturalLanguage Firebase/MLNLTranslate	GoogleMLKit/Translate

Update names of classes, enums, and types

In general, classes , enums, and types need to be renamed as follows:

Swift: Remove the Vision prefix from class names and enums
Objective-C: Replace both FIRVision and FIR class name and enum prefixes by MLK

For some class names and types this general rule does not apply:

Swift

Old class or type	New class or type
AutoMLLocalModel	LocalModel
AutoMLRemoteModel	CustomRemoteModel
VisionBarcodeDetectionCallback	BarcodeScanningCallback
VisionBarcodeDetector	BarcodeScanner
VisionBarcodeDetectorOptions	BarcodeScannerOptions
VisionImage	VisionImage (no change)
VisionPoint	VisionPoint (no change)
VisionOnDeviceAutoMLImageLabelerOptions	CustomImageLabelerOptions
VisionOnDeviceImageLabelerOptions	ImageLabelerOptions

Objective-C

Old class or type	New class or type
FIRAutoMLLocalModel	MLKLocalModel
FIRAutoMLRemoteModel	MLKCustomRemoteModel
FIRVisionBarcodeDetectionCallback	MLKBarcodeScanningCallback
FIRVisionBarcodeDetector	MLKBarcodeScanner
FIRVisionBarcodeDetectorOptions	MLKBarcodeScannerOptions
FIRVisionImage	MLKVisionImage
FIRVisionOnDeviceAutoMLImageLabelerOptions	MLKCustomImageLabelerOptions
FIRVisionOnDeviceImageLabelerOptions	MLKImageLabelerOptions
FIRVisionPoint	MLKVisionPoint

Objective-C

Update method names

Update method names according to these rules:

Domain entry point classes (Vision, NaturalLanguage) no longer exist. They have been replaced by task specific classes. Replace calls to their various factory methods for getting detectors with direct calls to each detector's factory method.
The VisionImageMetadata class has been removed, along with the VisionDetectorImageOrientation enum. Use the orientation property of VisionImage to specify the display orientation of an image.
The onDeviceTextRecognizer method that gets a new TextRecognizer instance has been renamed to textRecognizer.
The confidence property has been removed from text recognition result classes, including TextElement, TextLine, and TextBlock.
The onDeviceImageLabeler and onDeviceImageLabeler(options:) methods to get a new ImageLabeler instance have been merged and renamed to imageLabeler(options:).
The objectDetector method to get a new ObjectDetector instance has been removed. Use objectDetector(options:) instead.
The type property has been removed from ImageLabeler and the entityID property has been removed from the image labeling result class, ImageLabel.
The barcode scanning API detect(in _:, completion:) has been renamed to process(_:, completion:) to be consistent with other vision APIs.
The Natural Language APIs now use the term "language tag" (as defined by the BCP-47 standard) instead of "language code".
TranslateLanguage now uses readable names (like .english) for its constants instead of language tags ( like .en).

Here are some examples of old and new Swift methods:

Old

let options = VisionOnDeviceImageLabelerOptions()
options.confidenceThreshold = 0.75
let labeler = Vision.vision().onDeviceImageLabeler(options: options)

let detector = Vision.vision().faceDetector(options: options)

let localModel = AutoMLLocalModel(manifestPath: "automl/manifest.json")
let options = VisionOnDeviceAutoMLImageLabelerOptions(localModel: localModel)
options.confidenceThreshold = 0.75
let labeler = vision.onDeviceAutoMLImageLabeler(options: options)

let detector = Vision.vision().objectDetector()

New

let options = ImageLabelerOptions()
options.confidenceThreshold = NSNumber(value:0.75)
let labeler = ImageLabeler.imageLabeler(options: options)

let detector = FaceDetector.faceDetector(options: options)

let localModel = LocalModel(manifestPath: "automl/manifest.json")
let options = CustomImageLabelerOptions(localModel: localModel)
options.confidenceThreshold = NSNumber(value:0.75)
let labeler = ImageLabeler.imageLabeler(options: options)

let detector = ObjectDetector.objectDetector(options: ObjectDetectorOptions())

Here are some examples of old and new Objective-C methods:

Old

FIRVisionOnDeviceImageLabelerOptions *options = 
    [[FIRVisionOnDeviceImageLabelerOptions alloc] init];
options.confidenceThreshold = 0.75;
FIRVisionImageLabeler *labeler = 
    [[FIRVision vision] onDeviceImageLabelerWithOptions:options];

FIRVisionFaceDetector *detector =
    [[FIRVision vision] faceDetectorWithOptions: options];

FIRAutoMLLocalModel *localModel =
    [[FIRAutoMLLocalModel alloc] initWithManifestPath:@"automl/manifest.json"];
FIRVisionOnDeviceAutoMLImageLabelerOptions *options =
    [[FIRVisionOnDeviceAutoMLImageLabelerOptions alloc]
        initWithLocalModel: localModel];
options.confidenceThreshold = 0.75
FIRVisionImageLabeler *labeler =
    [[FIRVision vision] onDeviceAutoMLImageLabelerWithOptions:options];

FIRVisionObjectDetector *detector =
    [[FIRVision vision] objectDetector];

New

MLKImageLabelerOptions *options =
    [[MLKImageLabelerOptions alloc] init];
options.confidenceThreshold = @(0.75);
MLKImageLabeler *labeler =
    [MLKImageLabeler imageLabelerWithOptions:options];

MLKFaceDetector *detector =
    [MLKFaceDetector faceDetectorWithOptions:options];

MLKLocalModel *localModel =
    [[MLKLocalModel alloc]
        initWithManifestPath:@"automl/manifest.json"];
MLKCustomImageLabelerOptions *options =
    [[MLKCustomImageLabelerOptions alloc] initWithLocalModel:localModel];
options.confidenceThreshold = @(0.75)
MLKImageLabeler *labeler =
    [MLKImageLabeler imageLabelerWithOptions:options];

MLKObjectDetectorOptions *options = [[MLKObjectDetectorOptions alloc] init];
MLKObjectDetector *detector = [MLKObjectDetector objectDetectorWithOptions:options];

API-specific changes

Object detection and tracking

If your app uses object classification, be aware that the new SDK has changed the way returns the classification category for detected objects.

VisionObjectCategory in VisionObject is returned as text in an ObjectLabel object, instead of an integer. All possible string categories are included in the DetectedObjectLabel enum.

Note that the .unknown category has been removed. When the confidence of classifying an object is low, the classifier returns no label at all.

Here is an example of the old and new Swift code:

Old

if (object.classificationCategory == .food) {
    ...
}

New

if let label = object.labels.first {
  if (label.text == DetectedObjectLabel.food.rawValue) {
    ...
  }
}
// or
if let label = object.labels.first {
  if (label.index == DetectedObjectLabelIndex.food.rawValue) {
    ...
  }
}

Here is an example of the old and new Objective-C code:

Old

if (object.classificationCategory == FIRVisionObjectCategoryFood) {
    ...
}

New

if ([object.labels[0].text isEqualToString:MLKDetectedObjectLabelFood]) {
  ...
}
// or
if ([object.labels[0].index == MLKDetectedObjectLabelIndexFood]) {
  ...
}

Remove Firebase dependencies (Optional)

This step only applies when these conditions are met:

Firebase ML Kit is the only Firebase component you use
You only use on-device APIs
You don't use model serving

If this is the case, you can remove Firebase dependencies after migration. Follow these steps:

Remove the Firebase configuration file by deleting the GoogleService-Info.plist file from your app’s directory and your Xcode project.
Remove any Firebase cocoapod, such as pod 'Firebase/Analytics', from your Podfile.
Remove any FirebaseApp initialization, such as FirebaseApp.configure() from your code.
Delete your Firebase app at the Firebase console accroding to the instructions on the Firebase support site.

Getting Help

If you run into any issues, please check out our Community page where we outline the channels available for getting in touch with us.