Transform into a web extension

src/content/main.js

@@ -12,10 +12,48 @@ function injectApplication() {
 	var appContent = document.createElement("div");
 	appContent.id = ID;
 	appContent.style.zIndex = zIndex + 10;
-	appContent.appendChild(document.createTextNode("Here!"));
+	appContent.appendChild(document.createTextNode("Loading ..."));
 	document.body.insertBefore(appContent, document.body.firstChild);
 }
 
+function doFetchContent(contentType) {
+	return new Promise(function (resolve, reject) {
+		resolve({
+			contentType: contentType,
+			content: document.body.innerText
+		});
+	});
+}
+
+function doFetchLink(link) {
+	return new Promise(function (resolve, reject) {
+		var xmlHttp = new XMLHttpRequest();
+		xmlHttp.onreadystatechange = function () {
+			if (xmlHttp.readyState == 4) {
+				if (xmlHttp.status != 200) {
+					reject("HTTP error: " + xmlHttp.status);
+				}
+				var ct = xmlHttp.getResponseHeader("Content-Type");
+				resolve({
+					contentType: ct,
+					content: xmlHttp.responseText
+				});
+			}
+		}
+		xmlHttp.open("GET", link.url, true);
+		xmlHttp.setRequestHeader("Accept", link.type);
+		xmlHttp.send();
+	});
+}
+
+function injectContent(data) {
+	var root = document.getElementById(ID);
+	while (root.hasChildNodes()) {
+		root.removeChild(root.lastChild);
+	}
+	root.appendChild(document.createTextNode(data.content));
+}
+
 function onUpdateDeactivate() {
 	var root = document.getElementById(ID);
 	if (root == null)
@@ -23,16 +61,28 @@ function onUpdateDeactivate() {
 	root.parentNode.removeChild(root);
 }
 
-function onUpdateActivate(data) {
+function onUpdateActivate(linkedData) {
 	onUpdateDeactivate();
 	injectApplication();
+	var fetch = null;
+	if (linkedData.target == "content") {
+		fetch = doFetchContent(linkedData.syntax);
+	} else {
+		fetch = doFetchLink(linkedData.target)
+	}
+	fetch.then(function (result) {
+		injectContent(result);
+	}).catch(function (reason) {
+		var root = document.getElementById(ID);
+		root.innerText = reason;
+	});
 }
 
 chrome.runtime.onMessage.addListener(
 	function (request, sender, sendResponse) {
-		var activate = request.isActive && request.syntax != "";
+		var activate = request.isActive && request.linkedData.syntax != "";
 		if (activate)
-			onUpdateActivate(request);
+			onUpdateActivate(request.linkedData);
 		else
 			onUpdateDeactivate();
 	});