jmvtrinidad/app.html

## app.html
<template>
  <require from="./image-uploader"></require>
  Hello world!
  <image-uploader></image-uploader>
</template>

## app.js

export class App {
  message = 'sample'
}


## image-uploader.html
<template>

  <!-- markup for preview functionality, irrelevant here -->

  <input type="file" class="sr-only" id="${id}" aria-describedby="${id}-help" multiple accept="image/*" files.bind="imageGroup" />

  <label class="btn btn-default btn-sm" aria-hidden="true" for="${id}" role="button">
    <i class="fa fa-plus" aria-hidden="true"></i> Add files
  </label>

</template>

## image-uploader.js

import { bindable, bindingMode, autoinject, observable } from 'aurelia-framework';

export class ImageUploader {
  @bindable({ defaultBindingMode: bindingMode.twoWay }) imageArray = null;
  @bindable id = null;
  @bindable maxImageCount = 10;
  @bindable maxFileSizeKiloBytes = 2048;
  @observable imageGroup= [];
  constructor(dialogService) {
    this.dialogService = dialogService
  }

  idChanged(newValue) {

    if (!newValue) {
      throw Error('The id parameter needs a value in order to make the file uploader work.');
    }

  }

  imageGroupChanged(fileList) {
    console.log('imageGroup');
    if (!fileList || !fileList.length) return;
    if (!this.imageArray) return;

    for (let i = 0; i < fileList.length; ++i) {
      let file = fileList.item(i);

      if (this.imageArray.length >= this.maxImageCount) {
        // TODO: Alert: maximum number of images reached
      } else {
        if (file && file.type.startsWith('image/')) {
          // Size is in bytes. Div by 1024 to get kilobytes.
          if (file.size / (1024) > this.maxFileSizeKiloBytes) {
            // TODO: Alert: Image file too large.
          } else {
            this.imageArray.push(file);
          }
        } else {
          // TODO: Alert: unsupported media type.
        }
      }
    }
  }
}


## index.html
<!doctype html>
<html>
  <head>
    <title>Aurelia</title>
    <meta name="viewport" content="width=device-width, initial-scale=1">
  </head>
  <body aurelia-app>
    Loading...
    <script src="https://jdanyow.github.io/rjs-bundle/node_modules/requirejs/require.js"></script>
    <script src="https://jdanyow.github.io/rjs-bundle/config.js"></script>
    <script src="https://jdanyow.github.io/rjs-bundle/bundles/aurelia.js"></script>
    <script src="https://jdanyow.github.io/rjs-bundle/bundles/babel.js"></script>
    <script>
      require(['aurelia-bootstrapper']);
    </script>
  </body>
</html>

## main.js
export function configure(aurelia) {
  aurelia.use
    .standardConfiguration()
    .developmentLogging();

  aurelia.start().then(() => aurelia.setRoot());
}
	<template>
	<require from="./image-uploader"></require>
	Hello world!
	<image-uploader></image-uploader>
	</template>
	<template>

	<!-- markup for preview functionality, irrelevant here -->

	<input type="file" class="sr-only" id="${id}" aria-describedby="${id}-help" multiple accept="image/*" files.bind="imageGroup" />

	<label class="btn btn-default btn-sm" aria-hidden="true" for="${id}" role="button">
	<i class="fa fa-plus" aria-hidden="true"></i> Add files
	</label>

	</template>

	import { bindable, bindingMode, autoinject, observable } from 'aurelia-framework';

	export class ImageUploader {
	@bindable({ defaultBindingMode: bindingMode.twoWay }) imageArray = null;
	@bindable id = null;
	@bindable maxImageCount = 10;
	@bindable maxFileSizeKiloBytes = 2048;
	@observable imageGroup= [];
	constructor(dialogService) {
	this.dialogService = dialogService
	}

	idChanged(newValue) {

	if (!newValue) {
	throw Error('The id parameter needs a value in order to make the file uploader work.');
	}

	}

	imageGroupChanged(fileList) {
	console.log('imageGroup');
	if (!fileList \|\| !fileList.length) return;
	if (!this.imageArray) return;

	for (let i = 0; i < fileList.length; ++i) {
	let file = fileList.item(i);

	if (this.imageArray.length >= this.maxImageCount) {
	// TODO: Alert: maximum number of images reached
	} else {
	if (file && file.type.startsWith('image/')) {
	// Size is in bytes. Div by 1024 to get kilobytes.
	if (file.size / (1024) > this.maxFileSizeKiloBytes) {
	// TODO: Alert: Image file too large.
	} else {
	this.imageArray.push(file);
	}
	} else {
	// TODO: Alert: unsupported media type.
	}
	}
	}
	}
	}
	<!doctype html>
	<html>
	<head>
	<title>Aurelia</title>
	<meta name="viewport" content="width=device-width, initial-scale=1">
	</head>
	<body aurelia-app>
	Loading...
	<script src="https://jdanyow.github.io/rjs-bundle/node_modules/requirejs/require.js"></script>
	<script src="https://jdanyow.github.io/rjs-bundle/config.js"></script>
	<script src="https://jdanyow.github.io/rjs-bundle/bundles/aurelia.js"></script>
	<script src="https://jdanyow.github.io/rjs-bundle/bundles/babel.js"></script>
	<script>
	require(['aurelia-bootstrapper']);
	</script>
	</body>
	</html>
	export function configure(aurelia) {
	aurelia.use
	.standardConfiguration()
	.developmentLogging();

	aurelia.start().then(() => aurelia.setRoot());
	}