This angular 2 library provides a light-weight component that handles file-drop, image previewing and image uploading.

npm install angular2-image-upload --save

In your app.module.ts import it using @NgModule decorator.

@NgModule({
    imports: [
        ...,
        ImageUploadModule.forRoot(),
        ...
    ]
})

Now you have image-upload declaration and you can use it in your html code.

<image-upload></image-upload>

You can use bindings to configure this element for your needs.

[max]="100" - is the maximum number of pictures that can be uploaded through this element. Default is 100.

[url]="'example.com/images/upload'" - this is the url which can handle POST queries with multipart/form-data Content-Type. The query has a single field called image.

Note: images are sent individually one by one!

[preview]="false" - you can disable images preview.

If you need to send some headers with your request (for example Authorization headers), you can use [headers] directive like this.

<image-upload [url]="'my-url.com'"
  [headers]="[
    {header: 'Authorization', value: 'MyToken'}
  ]"></image-upload>

Note that headers are sent only if you provide a url.

[buttonCaption]="'Select Images'" - that is a button caption. Default is "Select Images". Note that letters on the button are all caps.

[dropBoxMessage]="'Drop your images here!'" - this is a message that is shown in drop area. Default is "Drop your images here!".

(onFileUploadFinish)="imageUploaded($event)". If [url] is specified this event is fired when component gets a responce from the server, also in this case event has field serverResponse which contains object returned by the server. If [url] is not specified it's fired immediately after an image(s) dropped into file-drop zone of choosed in file browser. So what you can do, is not specify [url] to handle upload yourself, for exapmple send the image into firebase storage. To get file use event.file.

(onRemove)="imageRemoved($event)" - this event is fired when remove button was clicked and the image preview was removed. Note that this library doesn't handle deletion from server so you should do it yourself. Event passed as the argument is the exact same object that was passed to the (imageUploaded) callback when image was added so you can access serverResponse to get a key to delete your image from server.

(isPending)="disableSendButton($event)" - this event is fired when pending state was changed. Event is just a boolean that represents the pending state. Pending state is true when and only when component avaits a response from the server, and false othervise. You can use it, for example, to disable send button in your form until all images are uploaded.

In the final state it should look something like this:

<image-upload
  [max]="100"
  [url]="'example.com/images/upload'"
  [headers]="[
    {header: 'Authorization', value: 'MyToken'}
  ]"
  [buttonCaption]="'Select Images!'"
  [dropBoxMessage]="'Drop your images here!'"
  (onFileUploadFinish)="imageUploaded($event)"
  (onRemove)="imageRemoved($event)"
  (isPending)="disableSendButton($event)"
></image-upload>