Angular
Real-time image resizing, automatic optimization, and file uploading in Angular using ImageKit.io.
This quick start guide shows you how to integrate ImageKit into an Angular application. The code samples covered here are hosted on GitHub: https://github.com/imagekit-samples/quickstart/tree/master/angular.
This guide walks you through the following topics:
For this tutorial, it is recommended to create an Angular dummy app, as shown below.
Create an Angular app:
We will be using the following in this guide:
- Node version 14.21.1
- Angular version 15
Let's use the
ng new <project name> CLI utility provided by Angular to build a new project:ng new imagekit-angular-app
Navigate to the project directory:
cd imagekit-angular-app/
Open up the project in your text editor of choice, and navigate to
src/app/. This is where we will do most of our work.Install libraries (if not already):
npm install
Now run the app:
npm start
In your web browser, navigate to
http://localhost:4200/You should see the dummy app created by Angular CLI.
For simplicity, let's remove everything from
src/app/app.component.html so we can begin with a clean slate.Let's add one line in
src/app/app.component.html to title our page :<h1>Imagekit Angular Demo</h1>
Now we can begin our work.
Install the ImageKit Angular SDK:
Installing the ImageKit Angular SDK in our app is pretty simple:
npm install --save imagekitio-angular
Before the SDK can be used, let's learn about and obtain the requisite initialization parameters:
urlEndpointis a required parameter. This can be obtained from the URL-endpoint section or the developer section on your ImageKit dashboard.publicKeyandauthenticationEndpointparameters are optional and only needed if you want to use the SDK for client-side file upload. These can be obtained from the developer section on your ImageKit dashboard.
ImageKit Components:
The SDK includes 3 Components and the ability to access the core component:
Let's import the SDK.
src/app/app.module.ts
import { ImagekitioAngularModule } from 'imagekitio-angular';
...
@NgModule({
...
imports: [
...
ImagekitioAngularModule.forRoot({
publicKey: environment.publicKey,
urlEndpoint: environment.urlEndpoint,
authenticationEndpoint: environment.authenticationEndpoint
})
],
...
})
...
Loading image from relative path:
Let's use the default image that we have. It should be available at the following URL:
https://ik.imagekit.io/demo/default-image.jpg
Let's fetch and display it! For this, we will use the
ik-image component.We use the tag
<ik-image> for rendering images. For now, we will do a simple image rendering with a path prop. For a full list of options, check hereLet's insert the following into
app.component.html.src/app/app.component.html
<ik-image
urlEndpoint="https://ik.imagekit.io/demo/"
path="default-image.jpg">
</ik-image>
Rendered HTML element:
<img src="https://ik.imagekit.io/demo/default-image.jpg" _ngcontent-vpo-c15="" urlendpoint="https://ik.imagekit.io/demo/" path="default-image.jpg" ng-reflect-url-endpoint="https://ik.imagekit.io/demo/" ng-reflect-path="default-image.jpg">
Your Angular app should now display the default image in its full size:
.png?alt=media)
Full sized image (1000px x 1000 px)
You can pass styles and other attributes as props. For e.g. let's add 400px width by adding the
transformation.width prop:Let's try creating a transformation object in
app.component.ts.src/app/app.component.ts
import { Transformation } from 'imagekit-javascript/dist/src/interfaces/Transformation';
...
export class AppComponent {
...
transformation: Array<Transformation> = [{
width: "400"
}];
...
}
And now, we can use it in
app.component.html as such:src/app/app.component.html
<ik-image
urlEndpoint="https://ik.imagekit.io/demo/"
path="default-image.jpg"
[transformation]="transformation"
>
</ik-image>
This is how the output should look now:
Resized image (width=400px)
Note that here we have set the width to 400px at the
<img> tag level only. Intrinsically, the fetched image is still 1000px wide.Loading image from an absolute path:
If you have an absolute image path coming from the backend API e.g.
https://www.custom-domain.com/default-image.jpg, then you can use the src prop to load the image.For example:
<ik-image
src="https://ik.imagekit.io/demo/default-image.jpg"
>
</ik-image>
The output looks like this:
Render image on custom domain via absolute path
Let’s now learn how to manipulate images using transformations.
The Angular SDK gives a name to each transformation parameter, e.g.,
height for h and width for the w parameter. It makes your code more readable. If the property does not match any of the available options, it is added as it is. See the full list of supported transformations in Angular SDK on GitHub.You can also use
h and w parameters instead of height and width.
See the complete list of transformations supported in ImageKit here.Let’s resize the default image to 200px height and width:
src/app/app.component.ts
...
transformation: Array<Transformation> = [{
height: "200",
width: "200"
}];
...
}
src/app/app.component.html
<ik-image
urlEndpoint="https://ik.imagekit.io/demo/"
path="default-image.jpg"
[transformation]="transformation"
>
</ik-image>
Rendered HTML element:
<img src="https://ik.imagekit.io/demo/tr:h-400,w-400/default-image.jpg" _ngcontent-qos-c15="" urlendpoint="https://ik.imagekit.io/demo/" class="lazyload" ng-reflect-url-endpoint="https://ik.imagekit.io/demo/" ng-reflect-path="default-image.jpg" ng-reflect-transformation="[object Object]">
Refresh your browser to get the resized image.
Resized Image (200x200px)
src/app/app.component.ts
...
transformation: Array<Transformation> = [{
width: "400",
quality: "10"
}];
...
}
Rendered HTML:
<img src="https://ik.imagekit.io/demo/tr:w-400,q-10/default-image.jpg" _ngcontent-hfw-c15="" urlendpoint="https://ik.imagekit.io/demo/" ng-reflect-url-endpoint="https://ik.imagekit.io/demo/" ng-reflect-path="default-image.jpg" ng-reflect-transformation="[object Object]">
Quality manipulation (q=10)
src/app/app.component.ts
...
transformation: Array<Transformation> = [{
height: "300",
width: "200",
cropMode: "extract"
}];
...
}
Rendered HTML element:
<img src="https://ik.imagekit.io/demo/tr:h-300,w-200,cm-extract/default-image.jpg" _ngcontent-vjd-c15="" urlendpoint="https://ik.imagekit.io/demo/" ng-reflect-url-endpoint="https://ik.imagekit.io/demo/" ng-reflect-path="default-image.jpg" ng-reflect-transformation="[object Object]">
Crop Mode Extract (200x300px)
Chained transformations provide a simple way to control the sequence in which transformations are applied.
First, we will apply resizing transformations:
src/app/app.component.ts
...
transformation: Array<Transformation> = [{
height: "300",
width: "200",
}];
...
}
Transformation URL:
<img src="https://ik.imagekit.io/demo/tr:h-300,w-200/default-image.jpg" _ngcontent-dsh-c15="" urlendpoint="https://ik.imagekit.io/demo/" ng-reflect-url-endpoint="https://ik.imagekit.io/demo/" ng-reflect-path="default-image.jpg" ng-reflect-transformation="[object Object]">
Resized and cropped (200x300px)
Now, rotate the image by 90 degrees.
src/app/app.component.ts
...
transformation: Array<Transformation> = [{
height: "300",
width: "200",
}, {
rt: "90"
}
];
...
}
Chained Transformation URL:
<img src="https://ik.imagekit.io/demo/tr:h-300,w-200:rt-90/default-image.jpg" _ngcontent-cqk-c15="" urlendpoint="https://ik.imagekit.io/demo/" ng-reflect-url-endpoint="https://ik.imagekit.io/demo/" ng-reflect-path="default-image.jpg" ng-reflect-transformation="[object Object],[object Object">
Resized, then rotated
Let’s flip the order of transformation and see what happens.
src/app/app.component.ts
...
transformation: Array<Transformation> = [{
rt: "90"
},{
height: "300",
width: "200",
}
];
...
}
Chained Transformation URL:
<img src="https://ik.imagekit.io/demo/tr:rt-90:h-300,w-200/default-image.jpg" _ngcontent-lvp-c15="" urlendpoint="https://ik.imagekit.io/demo/" ng-reflect-url-endpoint="https://ik.imagekit.io/demo/" ng-reflect-path="default-image.jpg" ng-reflect-transformation="[object Object],[object Object">
Rotated, then resized
For example, a text overlay can be used to superimpose text on an image. Try it like so:
src/app/app.component.ts
...
transformation: Array<Transformation> = [{
height: "300",
width: "300",
overlayText: 'ImageKit',
overlayTextFontSize: "50",
overlayTextColor: '0651D5',
}];
...
}
Rendered HTML element:
<img src="https://ik.imagekit.io/demo/tr:h-300,w-300,ot-ImageKit,ots-50,otc-0651D5/default-image.jpg" _ngcontent-twl-c15="" urlendpoint="https://ik.imagekit.io/demo/" ng-reflect-url-endpoint="https://ik.imagekit.io/demo/" ng-reflect-path="default-image.jpg" ng-reflect-transformation="[object Object]">
Text Overlay (300x300px)
You can lazy load images using the
loading prop in the ik-image component. When you use loading="lazy", all images that are immediately viewable without scrolling load normally. Those that are far below the device viewport are only fetched when the user scrolls near them.The SDK uses a fixed threshold based on the effective connection type to ensure that images are loaded early enough so that they have finished loading once the user scrolls near to them.
You should always set the height and width of the image element to avoid layout shift when lazy-loading images.
src/app/app.component.ts
...
transformation: Array<Transformation> = [{
height: "300"
width: "400"
}];
...
}
You should always set the height and width of the image element to avoid layout shift when lazy-loading images.
src/app/app.component.html
<ik-image
path={{path}}
urlEndpoint="https://ik.imagekit.io/demo/"
[transformation]="transformation"
loading="lazy"
height="300"
width="400"
>
</ik-image>
Rendered HTML element:
<img src="https://ik.imagekit.io/demo/tr:h-300,w-400/default-image.jpg" _ngcontent-vnv-c15="" urlendpoint="https://ik.imagekit.io/demo/" loading="lazy" ng-reflect-url-endpoint="https://ik.imagekit.io/demo/" ng-reflect-loading="lazy" ng-reflect-path="default-image.jpg" ng-reflect-transformation="[object Object]">
To improve user experience, you can use a low-quality blurred variant of the original image as a placeholder while the original image is being loaded in the background. Once the loading of the original image is finished, the placeholder is replaced with the original image.
src/app/app.component.ts
...
transformation: Array<Transformation> = [{
width: "400",
}];
lqip = {
active: true, quality: 20
};
...
}
src/app/app.component.html
<ik-image
path={{path}}
urlEndpoint="https://ik.imagekit.io/demo/"
[transformation]="transformation"
[lqip]="lqip"
>
</ik-image>
You have the option to lazy-load the original image only when the user scrolls near them. Until then, only a low-quality placeholder is loaded. This saves a lot of network bandwidth if the user never scrolls further down.
src/app/app.component.ts
...
transformation: Array<Transformation> = [{
height:"300",
width: "400",
}];
lqip = {
active: true
};
...
}
src/app/app.component.html
// Loading a blurred low quality image placeholder
// and lazy-loading original when the user scrolls near them
<ik-image
path={{path}}
urlEndpoint="https://ik.imagekit.io/demo/"
[transformation]="transformation"
[lqip]="lqip"
loading="lazy"
>
</ik-image>
Let's now learn how to upload an image to our media library.
Angular SDK provides
ik-upload component, which renders an input type="file" tag that you can use to upload files to the ImageKit media library directly from the client-side.To implement this functionality, a backend server is needed to authenticate the request using your API private key.
For this quickstart guide, we will create a sample Node.js server that will provide an authentication endpoint at
http://localhost:3000/auth.Let's a new folder,
server, and create files app.js and package.json inside the new folder in the project root.mkdir server
touch server/app.js
Package.json should look like:
{
"name": "server",
"version": "1.0.0",
"description": "Sample server for file upload using Imagekit SDK",
"main": "app.js",
"scripts": {
"server": "nodemon app"
},
"devDependencies": {
"cors": "^2.8.5",
"crypto": "^1.0.1",
"dotenv": "^8.2.0",
"express": "^4.17.1",
"nodemon": "^2.0.2",
"router": "^1.3.3",
"uuid": "^3.3.3"
}
}
Now do
npm install.Next we setup the content for
app.js.app.js
server/app.js
const dotenv = require('dotenv');
const express = require('express');
const router = express.Router();
var cors = require('cors');
const app = express();
app.use(cors());
dotenv.config();
const uuid = require('uuid');
const crypto = require("crypto");
const privateKey = process.env.PRIVATE_KEY;
router.get("/auth", function(req, res) {
var token = req.query.token || uuid.v4();
var expire = req.query.expire || parseInt(Date.now()/1000)+2400;
var privateAPIKey = `${privateKey}`;
var signature = crypto.createHmac('sha1', privateAPIKey).update(token+expire).digest('hex');
res.status(200);
res.send({
token : token,
expire : expire,
signature : signature
});
});
app.use("/",router);
app.listen(3000,function(){
console.log("Live at Port 3000");
});
We would also need a .env file to indicate value for PRIVATE_KEY. This can be taken from your imagekit account's setting page where PUBLIC_KEY can also be found. Sample .env file should look like this.
PRIVATE_KEY=<your-private-key>
authenticationEndpoint should be implemented in your backend. The SDK makes an HTTP GET request to this endpoint and expects a JSON response with three fields i.e. signature, token, and expire. Learn how to implement authenticationEndpoint on your server.Let's run the backend server.
cd server
npm run server
You should see a log saying that the app is “Live on port 3000”.
If you GET
http://localhost:3000/auth, you should see a JSON response like this. Actual values will vary.{
token: "5dd0e211-8d67-452e-9acd-954c0bd53a1f",
expire: 1601047259,
signature: "dcb8e72e2b6e98186ec56c62c9e62886f40eaa96"
}
Now that we have our authentication server up and running, let's configure the
publicKey and authenticationEndpoint in the frontend Angular app:publicKey: "<YOUR_PUBLIC_KEY>",
authenticationEndpoint: "<YOUR_AUTH_ENDPOINT e.g http:/localhost:3000/auth>"
For this, we will use the
ik-upload component as well as a couple of event handlers for upload error and success, onError and onSuccess respectively. Let's use it in our app.component.html file:<ik-upload
fileName="test.jpg"
(onError)="handleUploadError($event)"
(onSuccess)="handleUploadSuccess($event)"
>
</ik-upload>
This is how it looks in the UI:
Upload Image
Direct file uploading from the browser
Let’s now upload an image by selecting a file from the file input.
When you choose a file, the file is immediately uploaded. You can pass optional
onSuccess and onError callback functions as props like we have.You can verify that file was successfully uploaded by checking the browser console. In case of success, it should print a success message, like this:
Upload Success Response
The response object would look similar to this (values may vary):
{
"fileId": "63a2e985e809dd54b027a563",
"name": "test_RiCBw0ouh.jpg",
"size": 36919,
"versionInfo": {
"id": "63a2e985e809dd54b027a563",
"name": "Version 1"
},
"filePath": "/test_RiCBw0ouh.jpg",
"url": "https://ik.imagekit.io/yzyzyz/test_RiCBw0ouh.jpg",
"fileType": "image",
"height": 500,
"width": 500,
"thumbnailUrl": "https://ik.imagekit.io/yzyzyz/tr:n-ik_ml_thumbnail/test_RiCBw0ouh.jpg",
"AITags": null
}
After a successful upload, you should see the newly uploaded image in the Media Library section of your ImageKit dashboard.
If you don't see the image, check if there are any errors in the browser console log. Then verify whether the API private key has been configured correctly in the server app and if the server app is running.
Fetching uploaded file
Fetch the uploaded image and show in UI using
ik-image with the filePath returned in the upload response.<ik-image path="/test_RiCBw0ouh.png" ></ik-image>
The app should display your uploaded image correctly!
A more detailed example of how to use the file upload component (and an explanation of each advanced feature) is presented below:
src/app/app.component.ts
import { Component } from '@angular/core';
import { Transformation } from 'imagekit-javascript/dist/src/interfaces/Transformation';
@Component({
selector: 'app-root',
templateUrl: './app.component.html',
styleUrls: ['./app.component.css']
})
export class AppComponent {
validateFileFunction(res: any) {
console.log('validating')
if(res.size < 1000000){ // Less than 1mb
return true;
}
return false;
}
onUploadStartFunction(res: any) {
console.log('onUploadStart')
}
onUploadProgressFunction(res: any) {
console.log('progressing')
}
handleUploadSuccess(res: any) {
console.log('File upload success with response: ', res);
console.log(res.$ResponseMetadata.statusCode); // 200
console.log(res.$ResponseMetadata.headers); // headers
this.uploadedImageSource = res.url;
}
handleUploadError(err: any) {
console.log('There was an error in upload: ', err);
this.uploadErrorMessage = 'File upload failed.';
}
}
The
buttonRef property for ik-upload can be used so that the file selector component inside ik-upload will be invisible. This allows you to create your own button, with your own stylings, and reference it using #<buttonRefValue>.Here's an example:
<div>
<!-- This will be invisible -->
<ik-upload
[buttonRef]="myBtn"
>
</ik-upload>
<!-- Your own button! -->
<button #myBtn type="Button" class="myOwnClass" style="color:blue">
Upload
</button>
</div>
The
onUploadStart prop is called when the file upload starts. This can be used for common use cases like showing a spinner, progress bar, etc.The
onUploadProgress prop can be passed like above, which will have a ProgressEvent. This can be used to show the percentage of upload progress to the end user.Arbitrary validation (file type, file size, file name) etc can be added using the
validateFile prop. An example has been added above that shows how to prevent upload if the file size is bigger than 1 MB.All the parameters supported by the ImageKit Upload API can be passed as shown above (e.g.
extensions, webhookUrl, customMetadata etc.)Rendering videos works similarly to rendering images in terms of usage of
urlEndpoint param.Loading video from relative path:
src/app/app.component.html
<ik-video
urlEndpoint="https://ik.imagekit.io/demo/"
path="sample-video.mp4"
controls=true
>
</ik-video>
The possibilities for image manipulation and optimization with ImageKit are endless. Learn more about it here:
Last modified 7mo ago