First storage and traversal implementation

Author: yesco

background.js

@@ -1,14 +1,117 @@
+String.prototype.times = function(n) { return n < 1 ? '':Array(n+1).join(this); }
+
 console.log("hello, guys");
 
+//var mimeType = "text/xml";
+var mimeType = "text/html";
+
 chrome.browserAction.onClicked.addListener(function(tab) {
-	console.log(tab);
-	console.log("GET "+tab.url);
-	var xhr = new XMLHttpRequest();
-	xhr.open('GET', tab.url, true);
-	xhr.onreadystatechange = function() {
-		if (xhr.readyState === this.DONE) {
-			console.log(xhr.responseText);
-		}
-	}
-	xhr.send();
-});
+  console.log("TAB: ", tab);
+  var url = tab.url;
+  console.log("GET " + url);
+  var xhr = new XMLHttpRequest();
+  xhr.open('GET', url, true);
+  xhr.onreadystatechange = function() {
+    if (xhr.readyState === this.DONE) {
+      console.log("XHR: ", xhr);
+      console.log(xhr.responseText);
+      console.log("XML: ", xhr.responseXML);
+
+      store(url, xhr.responseText);
+
+      diffStored(url);
+
+      // doesn't work
+      //var parser = new DOMParser();
+      //var prevXML = parser.parseFromString(getPrev(url), mimeType);
+
+      var prevDiv = document.createElement("div");
+      prevDiv.innerHTML = getPrev(url);
+      document.body.appendChild(prevDiv);
+
+      var currDiv = document.createElement("div");
+      currDiv.innerHTML = getPrev(url);
+      document.body.appendChild(currDiv);
+
+      diffDOM(prevDiv, currDiv);
+    }
+  }
+  xhr.overrideMimeType(mimeType); // doesn't work with html
+  xhr.send();
+});
+
+function prevKey(url) { return url + "$$$PREV"; }
+
+function getPrev(url) { return localStorage.getItem(prevKey(url)); }
+function getCurr(url) { return localStorage.getItem(url); }
+
+function store(url, responseText) {
+  var prev = getCurr(url);
+  localStorage.setItem(prevKey(url), prev);
+  localStorage.setItem(url, responseText);
+}
+
+function diffStored(url) {
+  var prev = getPrev(url);
+  var cur = getCurr(url);
+  if (prev == cur) {
+    console.log("SAME SAME!");
+    return;
+  }
+}
+
+function diffDOM(prev, curr) {
+  console.log("diffDOM: ", prev, curr);
+  console.log("DOM: ", document);
+  traverse(0, prev);
+  //traverse(0, document);
+  //pTraverse(0, docu);
+}
+
+function pTraverse(level, prev, curr) {
+  if (!prev || !curr) return;
+  if (prev instanceof Function) return;
+  if (prev instanceof Number) return;
+  if (prev instanceof String) return;
+
+  if (curr instanceof Function) return;
+  if (curr instanceof Number) return;
+  if (curr instanceof String) return;
+
+  var prevC = prev.childNodes;
+  if (!prevC) return;
+
+  var currC = curr.childNodes;
+  if (!currC) return;
+
+  // TODO: compare number of nodes, find inserted?
+  for (var i in c) {
+    //if (!(i instanceof Number)) return; // not HTML element?
+    var n = c[i];
+    if (n instanceof HTMLElement) {
+      console.log(' '.times(level*2), "i=", i, n, n.innerText);
+    }
+    traverse(level+1, n);
+  }
+}
+
+function traverse(level, node) {
+  if (!node) return;
+  if (node instanceof Function) return;
+  if (node instanceof Number) return;
+  if (node instanceof String) return;
+
+  var c = node.childNodes;
+  if (!c) return;
+
+  for (var i in c) {
+    //if (!(i instanceof Number)) return; // not HTML element?
+    var n = c[i];
+    if (n instanceof HTMLElement) {
+      console.log(' '.times(level*2), "i=", i, n, n.innerText);
+    }
+    traverse(level+1, n);
+  }
+}
+
+console.log("loaded...");