enable firmware flashing from the web UI

esp-link/cgi.c

@@ -213,7 +213,8 @@ int ICACHE_FLASH_ATTR cgiMenu(HttpdConnData *connData) {
 #ifdef MQTT
         "\"REST/MQTT\", \"/mqtt.html\", "
 #endif
-        "\"Debug log\", \"/log.html\""
+        "\"Debug log\", \"/log.html\","
+        "\"Upgrade Firmware\", \"/flash.html\""
       " ], "
       "\"version\": \"%s\", "
       "\"name\": \"%s\""

html/flash.html

@@ -0,0 +1,44 @@
+  <div id="main">
+    <div class="header">
+      <h1>Upgrade Firmware</h1>
+    </div>
+
+    <div class="content">
+			<div class="pure-g">
+        <div class="pure-u-1 pure-u-md-1-2">
+          <div class="card">
+            <h1>Upgrade Firmware
+              <div id="fw-spinner" class="spinner spinner-small"></div>
+            </h1>
+            <form action="#" id="fw-form" class="pure-form" hidden>
+              <legend>Firmware Info</legend>
+							<p>
+							Current firmware: <span style="font-weight: bold;" id="current-fw"></span>
+							</p>
+              <div class="pure-form-stacked">
+								<p>
+								Make sure you upload the file called: <span style="font-weight: bold;" id="fw-slot"></span>
+								</p>
+                <label>Firmware File</label>
+                <input type="file" name="fw-file" id="fw-file"/>
+              </div>
+              <button id="fw-button" type="submit" class="pure-button button-primary">
+                Update the firmware
+              </button>
+            </form>
+          </div>
+        </div>
+      </div>
+    </div>
+  </div>
+</div>
+
+<script src="nanoajax.min.js"></script>
+<script src="flash.js"></script>
+<script type="text/javascript">
+onLoad(function() {
+  fetchFlash();
+  bnd($("#fw-form"), "submit", flashFirmware);
+});
+</script>
+</body></html>

html/flash.js

@@ -0,0 +1,40 @@
+//===== FLASH cards
+
+function flashFirmware(e) {
+  e.preventDefault();
+	var fw_data = document.getElementById('fw-file').files[0];
+			
+	$("#fw-form").setAttribute("hidden", "");
+	$("#fw-spinner").removeAttribute("hidden");
+  showNotification("Firmware is being updated ...");
+
+	nanoajax.ajax({url: '/flash/upload', method: 'POST', body: fw_data}, function (code, responseText, request) {
+		if(""+code == "200")
+		{
+			ajaxReq("GET", "/flash/reboot", function (resp) {
+    		showNotification("Firmware has been successfully updated!");
+				setTimeout(function(){ window.location.reload()}, 4000);
+
+				$("#fw-spinner").setAttribute("hidden", "");
+				$("#fw-form").removeAttribute("hidden");
+			});
+		}
+	})
+}
+
+function fetchFlash() {
+  ajaxReq("GET", "/flash/next", function (resp) {
+		$("#fw-slot").innerHTML = resp;
+  	$("#fw-spinner").setAttribute("hidden", "");
+  	$("#fw-form").removeAttribute("hidden");
+  });
+	ajaxJson("GET", "/menu", function(data) {
+      var v = $("#current-fw");
+      if (v != null) { v.innerHTML = data.version; }
+    }
+	);
+}
+
+function setMqtt(name, v) {
+  
+}