ahnv/imagekit-ios

iOS SDK for using ImageKit.io

ImageKit.io iOS SDK

ImageKit iOS Pod allows you to use real-time image resizing, optimization, and file uploading in the client-side.

Table of contents

• Installation
• Initialization
• URL construction
• Components
• ImageKit
  • List of supported transformations
  • Responsive image loading
• Constructing Video URLs
  • Adaptive bitrate streaming
• File Upload
  • Upload policy
• Upload preprocessing
  • Image preprocessing
  • Video preprocessing
• Support
• Links
• License

Installation

Requirements

The library requires Swift 4.0 or above.

CocoaPods

You can use CocoaPods to install ImageKit by adding it to your Podfile:

use_frameworks!

target 'target_name' do
    pod 'ImageKitIO'
end

Initialization

urlEndpoint is the required parameter. You can get the value of URL-endpoint from your ImageKit dashboard - https://imagekit.io/dashboard#url-endpoints.

publicKey parameter is optional and only needed if you want to use the SDK for client-side file upload. You can get this parameter from the developer section in your ImageKit dashboard - https://imagekit.io/dashboard#developers.

transformationPosition is optional. The default value for this parameter is TransformationPosition.PATH. Acceptable values are TransformationPosition.PATH & TransformationPosition.QUERY

Note: Do not include your Private Key in any client-side code, including this SDK or its initialization.

// AppDelegate.swift

ImageKit.init(
    publicKey: "your_public_api_key=", 
    urlEndpoint: "https://ik.imagekit.io/your_imagekit_id", 
    transformationPosition: TransformationPosition.PATH,
    defaultUploadPolicy: UploadPolicy.Builder()
        .requireNetworkType(UploadPolicy.NetworkType.ANY)
        .setMaxRetries(3)
        .build()
)

Quick Examples

URL construction

Using image path

//https://ik.imagekit.io/your_imagekit_id/default-image.jpg?tr=h-400.00,ar-3-2
ImageKit.shared.url(
    path: "default-image.jpg",
    transformationPosition: TransformationPosition.QUERY
)
.height(height: 400)
.aspectRatio(width: 3, height: 2)
.create()

Using full image URL

// https://ik.imagekit.io/your_imagekit_id/medium_cafe_B1iTdD0C.jpg?tr=oi-logo-white_SJwqB4Nfe.png,ox-10,oy-20
ImageKit.shared.url(
    src: "https://ik.imagekit.io/your_imagekit_id/medium_cafe_B1iTdD0C.jpg",
    transformationPosition: "path"
)
.create()

Using a custom parameter

// https://ik.imagekit.io/your_imagekit_id/plant.jpeg?tr=w-400,ot-Hand with a green plant,otc-264120,ots-30,ox-10,oy-10
ImageKit.shared.url(
    src : "https://ik.imagekit.io/your_imagekit_id/plant.jpeg?tr=oi-logo-white_SJwqB4Nfe.png,ox-10,oy-20"
)
.addCustomTransformation("w", "400")
.create()

Upload file from UIImage

let image: UIImage
ImageKit.shared.uploader().upload(
    file: image,
    fileName: "sample-image.jpg",
    useUniqueFilename: true,
    tags: ["demo"],
    folder: "/",
    isPrivateFile: false,
    customCoordinates: "",
    responseFields: "",
    progress: { progress in
    // Handle Progress
    },
    completion: { result in 
     switch result{
            case .success(let uploadAPIResponse):
                // Handle Success Response
            case .failure(let error as UploadAPIError):
                // Handle Upload Error
            case .failure(let error):
                // Handle Other Errors
      }
    }
)

Upload file from a remote URL

ImageKit.shared.uploader().upload(
    file: "https://www.example.com/sample-image.jpg",
    fileName: "sample-image.jpg",
    useUniqueFilename: true,
    tags: ["demo"],
    folder: "/",
    isPrivateFile: false,
    customCoordinates: "",
    responseFields: "",
    progress: { progress in
    // Handle Progress
    },
    completion: { result in 
     switch result{
            case .success(let uploadAPIResponse):
                // Handle Success Response
            case .failure(let error as UploadAPIError):
                // Handle Upload Error
            case .failure(let error):
                // Handle Other Errors
      }
    }
)

Upload file using Data

let data : Data
ImageKit.shared.uploader().upload(
    file: data,
    fileName: "sample-image.jpg",
    useUniqueFilename: true,
    tags: ["demo"],
    folder: "/",
    isPrivateFile: false,
    customCoordinates: "",
    responseFields: "",
    progress: { progress in
    // Handle Progress
    },
    completion: { result in 
     switch result{
            case .success(let uploadAPIResponse):
                // Handle Success Response
            case .failure(let error as UploadAPIError):
                // Handle Upload Error
            case .failure(let error):
                // Handle Other Errors
      }
    }
)

Demo application

• The official step by step iOS quick start guide - https://docs.imagekit.io/getting-started/quickstart-guides/ios
• You can also run the demo application in Example folder by running pod install and then open ImageKit.xcworkspace in the terminal.

Components

The library includes 3 Primary Classes:

• ImageKit for defining options like urlEndpoint, publicKey or authenticationEndpoint for the application to use.
• ImageKitURLConstructor for constructing image urls.
• ImageKitUploaderfor client-side file uploading.
• UploadPolicy for setting a set of policy constraints that need to be validated for an upload request to be executed.
• ImageUploadPreprocessor to set the parameters for preprocessing the image to be uploaded.

ImageKit

In order to use the SDK, you need to provide it with a few configuration parameters.

ImageKit.init(
    urlEndpoint: "https://ik.imagekit.io/your_imagekit_id", // Required.
    publicKey: "your_public_api_key=",  //Optional
    transformationPosition: TransformationPosition.PATH, //Optional
)

• urlEndpoint is required to use the SDK. You can get URL-endpoint from your ImageKit dashboard - https://imagekit.io/dashboard#url-endpoints.
• publicKey parameter is required if you want to use the SDK for client-side file upload. You can get this parameter from the developer section in your ImageKit dashboard - https://imagekit.io/dashboard#developers.
• transformationPosition is optional. The default value for this parameter is TransformationPosition.PATH. Acceptable values are TransformationPosition.PATH & TransformationPosition.QUERY

Note: Do not include your Private Key in any client-side code.

Constructing Image URLs

The ImageKitURLConstructor is used to create a url that can be used for rendering and manipulating images in real-time. ImageKitURLConstructor consists of functions that can be chained together to perform transformations.

ImageKitURLConstructor can be initialized by calling ImageKit.shared.url(...) with a set of parameters defined below.

Parameter	Type	Description
urlEndpoint	String	Optional. The base URL to be appended before the path of the image. If not specified, the URL-endpoint specified in the parent IKContext component is used. For example, https://ik.imagekit.io/your_imagekit_id/endpoint/
path	String	Conditional. This is the path at which the image exists. For example, /path/to/image.jpg. Either the path or src parameter needs to be specified for URL generation.
src	String	Conditional. This is the complete URL of an image already mapped to ImageKit. For example, https://ik.imagekit.io/your_imagekit_id/endpoint/path/to/image.jpg. Either the path or src parameter needs to be specified for URL generation.
transformationPosition	TransformationPosition	Optional. The default value is .PATH that places the transformation string as a URL path parameter. It can also be specified as .QUERY, which adds the transformation string as the URL's query parameter i.e.tr. If you use src parameter to create the URL, then the transformation string is always added as a query parameter.

The transformations to be applied to the URL can be chained to ImageKit.shared.url(...). See the list of different tranformations. Different steps of a chained transformation can be added by calling the function chainTransformation.

Basic Examples

// https://ik.imagekit.io/your_imagekit_id/default-image.jpg?tr=h-400.00,ar-3-2
ImageKit.shared.url(
    path: "default-image.jpg",
    transformationPosition: TransformationPosition.QUERY
)
.height(height: 400)
.aspectRatio(width: 3, height: 2)
.create()

More Examples can be found in Tests/Tests.swift

List of supported transformations

The complete list of transformations supported and their usage in ImageKit can be found here. The SDK provides a function for each transformation parameter, making the code simpler and readable. If a transformation is supported in ImageKit, but if a name for it cannot be found in the table below, then use the addCustomTransformation function and pass the transformation code from ImageKit docs as the first parameter and value as the second parameter. For example - .addCustomTransformation("w", "400")

Expand

Supported Transformation Name	Transformation Function Prototypes	Translates to parameter
height	height(height: Int)	h
width	width(width: Int)	w
aspectRatio	aspectRatio(width: Int, height: Int)	ar
quality	quality(quality: Int)	q
crop	crop(cropType: CropType)	c
cropMode	cropMode(cropMode: CropMode)	cm
x, y	focus(x: Int, y: Int)	x, y
focus	focus(focusType: FocusType)	fo
format	format(format: Format)	f
radius	radius(radius: Int)	r
background	background(backgroundColor: String) background(backgroundColor: UIColor)	bg
border	border(borderWidth: Int, borderColor: String) border(borderWidth: Int, borderColor: UIColor)	b
rotation	rotation(rotation: Rotation)	rt
blur	blur(blur: Int)	bl
named	named(namedTransformation: String)	n
progressive	progressive(flag: Bool)	pr
lossless	lossless(flag: Bool)	lo
trim	trim(flag: Bool) trim(value: Int)	t
metadata	metadata(flag: Bool)	md
colorProfile	colorProfile(flag: Bool)	cp
defaultImage	defaultImage(defaultImage: String)	di
dpr	dpr(dpr: Float)	dpr
effectSharpen	effectSharpen(value: Int = 0)	e-sharpen
effectUSM	effectUSM(radius: Float, sigma: Float, amount: Float, threshold: Float)	e-usm
effectContrast	effectContrast(flag: Bool)	e-contrast
effectGray	effectGray(flag: Bool)	e-grayscale
original	original()	orig
Raw transformation string	raw(params: String)	-

Responsive image loading

ImageKit URL constructor can be set to input any instance of UIView and determine the parameters for image height and width based on the dimensions of the view. If the view's dimensions are not set at the time, it uses the display's dimensions as the fallback. It also sets the DPR of the image automatically to match that of the device display. To automatically set the dimensions and pixel ratio of the image , call ImageKit.shared.url(...).setResponsive(...) with a set of parameters defined below:

Parameter	Type	Description
view	UIView	Specifies the reference of the view of which the dimensions are to be taken into consideration for image sizing.
minSize	Int	Optional. Explicitly sets the minimum size for image dimensions. Defaults to 0. Passing a negative value will throw an InvalidArgumentError.
maxSize	Int	Optional. Explicitly sets the maximum size for image dimensions. Defaults to Int.MAX_VALUE. Passing a negative value will throw an InvalidArgumentError.
step	Int	Optional. Explicitly sets the step in pixels for rounding the dimensions to the nearest next multiple of step. Defaults to 100. Passing a negative value will throw an InvalidArgumentError.
crop	CropMode	Optional. Explicitly sets the mode for image cropping. Defaults to CropMode.RESIZE.
focus	FocusType	Optional. Specifies the area of the image to be set as the focal point for crop transform. Defaults to FocusType.CENTER.

Code example:

// https://ik.imagekit.io/your_imagekit_id/default-image.jpg?tr=h-400.00,w-400.00,
ImageKit.shared.url(
    path: "default-image.jpg",
    transformationPosition: TransformationPosition.QUERY
)
.setResponsive(
    view: displayView,
    crop: CropMode.EXTRACT,
    focus: FocusType.TOP_LEFT
)
.create()

Constructing Video URLs

The ImageKitURLConstructor can also be used to create a url that can be used for streaming videos with real-time transformations. ImageKitURLConstructor consists of functions that can be chained together to perform transformations.

The initialization is same as that for image URLs by calling ImageKit.shared.url(...) with a set of parameters defined below.

Basic Examples

// https://ik.imagekit.io/your_imagekit_id/default-video.mp4?tr=h-400.00,w-400.00
ImageKit.shared.url(
    path: "default-video.mp4",
    transformationPosition: TransformationPosition.QUERY
)
.height(height: 400)
.width(width: 400)
.create()

Adaptive bitrate streaming

To obtain the video URL with adaptive streaming, call ImageKit.shared.url(...).setAdaptiveStreaming(...) with a set of parameters defined below.

Parameter	Type	Description
format	StreamingFormat	Specifies the format for streaming video. Supported values for type are StreamingFormat.HLS and StreamingFormat.DASH.
resolutions	[Int]	Specifies the representations of the required video resolutions. E. g. 480, 720, 1080 etc.

Code example:

// https://ik.imagekit.io/your_imagekit_id/default-video.mp4/ik-master.m3u8?tr=sr-240_360_480_720_1080_1440_2160
ImageKit.shared.url(
    path: "default-video.mp4",
    transformationPosition: TransformationPosition.QUERY
)
.setAdaptiveStreaming(
    format: StreamingFormat.HLS,
    resolutions: [240, 360, 480, 720, 1080, 1440, 2160]
)
.create()

File Upload

The SDK provides a simple interface using the ImageKit.shared.uploader().upload(...) method to upload files to the ImageKit Media Library. It accepts all the parameters supported by the ImageKit Upload API.

The ImageKit.shared.uploader().upload(...) accepts the following parameters

Parameter	Type	Description
file	Data / UIImage / String	Required.
fileName	String	Required. If not specified, the file system name is picked.
token	String	Required. The client-generated JSON Web Token (JWT), which the ImageKit.io server uses to authenticate and check that the upload request parameters have not been tampered with after the generation of the token. Refer this guide to create the token below on the page.
useUniqueFileName	Bool	Optional. Accepts true of false. The default value is true. Specify whether to use a unique filename for this file or not.
tags	Array of string	Optional. Set the tags while uploading the file e.g. ["tag1","tag2"]
folder	String	Optional. The folder path (e.g. /images/folder/) in which the file has to be uploaded. If the folder doesn't exist before, a new folder is created.
isPrivateFile	Bool	Optional. Accepts true of false. The default value is false. Specify whether to mark the file as private or not. This is only relevant for image type files
customCoordinates	String	Optional. Define an important area in the image. This is only relevant for image type files. To be passed as a string with the x and y coordinates of the top-left corner, and width and height of the area of interest in format x,y,width,height. For example - 10,10,100,100
responseFields	[String]	Optional. Values of the fields that you want upload API to return in the response. For example, set the value of this field to ["tags", "customCoordinates", "isPrivateFile"] to get value of tags, customCoordinates, and isPrivateFile in the response.
extensions	[[String : Any]]	Optional. array of extensions to be processed on the image. For reference about extensions read here.
webhookUrl	String	Optional. Final status of pending extensions will be sent to this URL. To learn more about how ImageKit uses webhooks, read here.
overwriteFile	Bool	Optional. Default is true. If overwriteFile is set to false and useUniqueFileName is also false, and a file already exists at the exact location, upload API will return an error immediately.
overwriteAITags	Bool	Optional. Default is true. If set to true and a file already exists at the exact location, its AITags will be removed. Set this to false to preserve AITags.
overwriteTags	Bool	Optional. Default is true. If the request does not have tags, overwriteTags is set to true and if a file already exists at the exact location, exiting tags will be removed. In case the request body has tags, setting overwriteTags to false has no effect and request's tags are set on the asset.
overwriteCustomMetadata	Bool	Optional. Default is true. If the request does not have customMetadata, overwriteCustomMetadata is set to true and if a file already exists at the exact location, exiting customMetadata will be removed. In case the request body has customMetadata, setting overwriteCustomMetadata to false has no effect and request's customMetadata is set on the asset.
customMetadata	[String : Any]	Optional. Key-value data to be associated with the uploaded file. Check overwriteCustomMetadata parameter to understand default behaviour. Before setting any custom metadata on an asset you have to create the field using custom metadata fields API.
policy	UploadPolicy	Optional. Set the custom policy to override the default policy for this upload request only. This doesn't modify the default upload policy.
progress	((Progress) -> Void)	Optional.
completion	(Result<(HTTPURLResponse?, UploadAPIResponse?), Error>) -> Void	Required.

Note

Sending a JWT that has been used in the past will result in a validation error. Even if your previous request resulted in an error, you should always send a new JWT as the token parameter.

Warning

JWT must be generated on the server-side because it is generated using your account's private API key. This field is required for authentication when uploading a file from the client-side.

Sample Usage

ImageKit.shared.uploader().upload(
    file: image,
    fileName: "sample-image.jpg",
    useUniqueFilename: true,
    tags: ["demo"],
    folder: "/",
    isPrivateFile: false,
    customCoordinates: "",
    responseFields: "",
    extensions: [["name": "google-auto-tagging", "minConfidence": 80, "maxTags": 10]],
    webhookUrl: "https://abc.xyz",
    overwriteFile: false,
    overwriteAITags: true,
    overwriteTags: true,
    overwriteCustomMetadata: true,
    customMetadata: ["SKU": "VS882HJ2JD", "price": 599.99, "brand": "H&M"],
    progress: { progress in
    // Handle Progress
    },
    completion: { result in 
     switch result{
            case .success(let uploadAPIResponse):
                // Handle Success Response
            case .failure(let error as UploadAPIError):
                // Handle Upload Error
            case .failure(let error):
                // Handle Other Errors
      }
    }
)

UploadPolicy

The UploadPolicy class represents a set of conditions that need to be met for an upload request to be executed.

UploadPolicy.Builder class is responsible for building the UploadPolicy instances. This class provides following methods to access and modify the policy parameters:

Parameter	Type	Description
requireNetworkType(type: NetworkType)	UploadPolicy.Builder	Specifies the network type required for the upload request. Possible values are UploadPolicy.NetworkPolicy.ANY and UploadPolicy.NetworkPolicy.UNMETERED. Defaults to NetworkPolicy.ANY.
requiresBatteryCharging(requiresCharging: Bool)	UploadPolicy.Builder	Sets whether the device needs to be connected to a charger for the upload request. Defaults to false.
setMaxRetries(count: Int)	UploadPolicy.Builder	Sets the maximum number of retries for the upload request. Negative value will throw an IllegalArgumentException. Defaults to 5.
setRetryBackoff(interval: Long, policy: UploadPolicy.BackoffPolicy)	UploadPolicy.Builder	Sets the backoff interval in milliseconds and policy (UploadPolicy.BackoffPolicy.LINEAR or UploadPolicy.BackoffPolicy.EXPONENTIAL) for retry attempts. Defaults to interval of 1000ms and policy of BackoffPolicy.linear. This increases the gap between each upload retry in either linear or exponential manner. E. g. if the interval is set to 3 seconds, then delay for each retry (n) will increase as following: With linear backoff: 3, 6, 9, 12 seconds.. (interval * n). With exponential backoff: 3, 6, 12, 24 seconds.. (interval * 2n-1).

Example code

let policy = UploadPolicy.Builder()
    .requireNetworkType(UploadPolicy.NetworkType.UNMETERED)
    .requiresCharging(true)
    .setMaxRetries(5)
    .setRetryBackoff(60000, UploadPolicy.BackoffPolicy.EXPONENTIAL)
    .build()

Upload preprocessing

Image preprocessing

The ImageUploadPreprocessor class encapsulates a set of methods to apply certain transformations to an image before uploading. This will create a copy of the selected image, which will be transformed as per the given parameters before uploading.

ImageUploadPreprocessor.Builder class is responsible for building the ImageUploadPreprocessor instances. This class provides following methods to access and modify the policy parameters:

Parameter	Type	Description
limit(width: Int, height: Int)	ImageUploadPreprocessor.Builder	Specifies the maximum width and height of the image
crop(p1: Point, p2: Point)	ImageUploadPreprocessor.Builder	Specifies the two points on the diagonal of the rectangle to be cropped.
format(format: ImageUploadPreprocessor.OutputFormat)	ImageUploadPreprocessor.Builder	Specify the target image format. Possible values are ImageUploadPreprocessor.OutputFormat.JPEG and ImageUploadPreprocessor.OutputFormat.PNG. Defaults to .PNG
rotate(degrees: Float)	ImageUploadPreprocessor.Builder	Specify the rotation angle of the target image.

Example code

let preprocessor = ImageUploadPreprocessor.Builder()
   .limit(width: 400, height: 300)
   .rotate(degrees: 45)
   .format(format: .JPEG)
   .build()

Video preprocessing

The VideoUploadPreprocessor class encapsulates a set of methods to apply certain transformations to an image before uploading. This will create a copy of the selected image, which will be transformed as per the given parameters before uploading.

VideoUploadPreprocessor.Builder class is responsible for building the VideoUploadPreprocessor instances. This class provides following methods to access and modify the policy parameters:

Parameter	Type	Description
limit(width: Int, height: Int)	VideoUploadPreprocessor.Builder	Specifies the maximum width and height of the video
frameRate(frameRateValue: Int)	VideoUploadPreprocessor.Builder	Specifies the target frame rate of the video.
keyFramesInterval(interval: Int)	VideoUploadPreprocessor.Builder	Specify the target keyframes interval of video.
targetAudioBitrateKbps(targetAudioBitrateKbps: Int)	VideoUploadPreprocessor.Builder	Specify the target audio bitrate of the video.
targetVideoBitrateKbps(targetVideoBitrateKbps: Int)	VideoUploadPreprocessor.Builder	Specify the target video bitrate of the video.

Example code

let preprocessor = VideoUploadPreprocessor.Builder()
   .limit(width: 800, height: 600)
   .frameRate(frameRateValue: 60)
   .keyFramesInterval(interval: 6)
   .targetVideoBitrateKbps(targetVideoBitrateKbps: 480)
   .targetAudioBitrateKbps(targetAudioBitrateKbps: 320)
   .build(),

Support

For any feedback or to report any issues or general implementation support, please reach out to [email protected]

Links

• Documentation
• Main website

License

Released under the MIT license.