Added upload function which tracks progress

package.json

@@ -1,6 +1,6 @@
 {
 	"name": "@ztimson/utils",
-	"version": "0.6.0",
+	"version": "0.8.0",
 	"description": "Utility library",
 	"author": "Zak Timson",
 	"license": "MIT",

src/download.ts

@@ -1,7 +1,8 @@
-import {TypedEmitter, TypedEvents} from './emitter.ts';
+import {TypedEmitter, TypedEvents} from './emitter';
 
-export type downloadEvents = TypedEvents & {
+export type DownloadEvents = TypedEvents & {
 	complete: (blob: Blob) => any;
+	failed: (error: Error) => any;
 	progress: (progress: number) => any;
 }
 
@@ -14,9 +15,18 @@ export function download(href: any, name: string) {
 	document.body.removeChild(a);
 }
 
-export function downloadStream(url: string, name?: string) {
-	const emitter = new TypedEmitter<downloadEvents>();
+/**
+ * Download a URL using fetch so progress can be tracked. Uses Typed Emitter to emit a "progress" &
+ * "complete" event.
+ *
+ * @param {string} url
+ * @param {string} downloadName
+ * @return {TypedEmitter<DownloadEvents>}
+ */
+export function downloadProgress(url: string, downloadName?: string) {
+	const progress = new TypedEmitter<DownloadEvents>();
 	fetch(url).then(response => {
+		if(!response.ok) return progress.emit('failed', new Error(response.statusText));
 		const contentLength = response.headers.get('Content-Length') || '0';
 		const total = parseInt(contentLength, 10);
 		let chunks: any[] = [], loaded = 0;
@@ -24,23 +34,20 @@ export function downloadStream(url: string, name?: string) {
 		reader?.read().then(function processResult(result) {
 			if(result.done) {
 				const blob = new Blob(chunks);
-				emitter.emit('progress', 1);
-				if(name) {
+				if(downloadName) {
 					const url = URL.createObjectURL(blob);
-					download(url, name);
+					download(url, downloadName);
 					URL.revokeObjectURL(url);
 				}
-				emitter.emit('complete', blob);
-				return;
+				progress.emit('complete', blob);
 			} else {
 				const chunk = result.value;
 				chunks.push(chunk);
 				loaded += chunk.length;
-				const progress = Math.round((loaded / total) * 100);
-				emitter.emit('progress', progress);
+				progress.emit('progress', loaded / total);
 				reader.read().then(processResult);
 			}
 		});
-	});
-	return emitter;
+	}).catch(err => progress.emit('failed', err));
+	return progress;
 }

src/index.ts

@@ -1,6 +1,6 @@
 export * from './array';
 export * from './aset';
-export * from './download.ts';
+export * from './download';
 export * from './emitter';
 export * from './errors';
 export * from './logger';
@@ -8,4 +8,5 @@ export * from './misc';
 export * from './objects';
 export * from './string';
 export * from './time';
+export * from './upload';
 export * from './xhr';

src/upload.ts

@@ -0,0 +1,30 @@
+import {TypedEmitter, TypedEvents} from './emitter';
+
+export type UploadEvents = TypedEvents & {
+	complete: () => any;
+	failed: (err: Error) => any;
+	progress: (progress: number) => any;
+}
+
+function uploadProgress(files : File | FileList, url: string) {
+	const xhr = new XMLHttpRequest();
+	const progress = new TypedEmitter<UploadEvents>();
+	const formData = new FormData();
+	(Array.isArray(files) ? files : [files])
+		.forEach(f => formData.append('file', f));
+
+	xhr.upload.addEventListener("progress", (event) => {
+		if(event.lengthComputable) progress.emit('progress', event.loaded / event.total);
+	});
+
+	xhr.onreadystatechange = () => {
+		if (xhr.readyState === 4) {
+			if(xhr.status >= 200 && xhr.status < 300) progress.emit('complete');
+			else progress.emit('failed', new Error(xhr.responseText));
+		}
+	};
+
+	xhr.open("POST", url, true);
+	xhr.send(formData);
+	return progress;
+}