Add parse post data middleware example

.npmignore

@@ -6,3 +6,4 @@ logo-large.png
 docs.css
 build
 .gitmodules
+examples/

examples/parse_post_data.mjs

@@ -0,0 +1,43 @@
+"use strict";
+
+import RouterContext from 'powahroot/Server/RouterContext.mjs';
+//import { middleware_catch_errors } from './monitor.mjs';
+
+// Maximum body size in characters
+const max_request_body_length = 128 * 1024; // 128K
+
+
+function depostify(postdata) {
+	return postdata.split("&").reduce(function (decoded, chunk) {
+		chunk = chunk.split("=").map(decodeURIComponent);
+		decoded[chunk[0]] = chunk[1];
+		return decoded;
+	}, {})
+}
+
+
+/**
+ * Parses URL-encoded POST data out into the context.env.post_data variable.
+ * @param	{RouterContext}	context	The context object.
+ * @param	{Function}		next	Function to invoke the next middleware item
+ */
+async function middleware_parse_post(context, next) {
+	let raw_post_data = "";
+	context.request.on("data", async (chunk) => {
+		if(raw_post_data.length + chunk.length > max_request_body_length) {
+			context.send.plain(413, "Error: Request payload was too large.");
+			return;
+		}
+		raw_post_data += chunk;
+	});
+	
+	context.request.on("end", async () => {
+		context.env.post_data = depostify(raw_post_data);
+		// Institute another error-catching safety net. This is needed because
+		// we're in an event here, which breaks the async chain.
+		//await middleware_catch_errors(context, next);
+		await next();
+	});
+}
+
+export default middleware_parse_post;