Added filebrowser & Merged a bunch of functions into file utilities

src/files.ts

@@ -0,0 +1,54 @@
+import {PromiseProgress} from './promise-progress.ts';
+
+export function download(href: any, name: string) {
+	const a = document.createElement('a');
+	a.href = href;
+	a.download = name;
+	document.body.appendChild(a);
+	a.click();
+	document.body.removeChild(a);
+}
+
+export function downloadBlob(blob: Blob, name: string) {
+	const url = URL.createObjectURL(blob);
+	download(url, name);
+	URL.revokeObjectURL(url);
+}
+
+export function fileBrowser(options: {accept?: string, multiple?: boolean} = {}): Promise<File[]> {
+	return new Promise(res => {
+		const input = document.createElement('input');
+		input.type = 'file';
+		input.accept = options.accept || '*';
+		input.style.display='none';
+		input.multiple = !!options.multiple;
+		input.onblur = input.onchange = async () => {
+			res(Array.from(<any>input.files));
+			input.remove();
+		}
+		document.body.appendChild(input);
+		input.click();
+	});
+}
+
+export function uploadWithProgress(options: {
+	url: string;
+	file: File;
+	headers?: {[key: string]: string};
+	withCredentials?: boolean;
+}) {
+	return new PromiseProgress((res, rej, prog) => {
+		const xhr = new XMLHttpRequest();
+		const formData = new FormData();
+		formData.append('file', options.file);
+
+		xhr.withCredentials = !!options.withCredentials
+		Object.entries(options.headers || {}).forEach(([key, value]) => xhr.setRequestHeader(key, value));
+		xhr.upload.addEventListener('progress', (event) => event.lengthComputable ? prog(event.loaded / event.total) : null);
+		xhr.upload.addEventListener('load', (resp) => res(resp));
+		xhr.upload.addEventListener('error', (err) => rej(err));
+
+		xhr.open('POST', options.url);
+		xhr.send(formData);
+	});
+}