Check server connection and app version, close #12, close #13

package.json

@@ -40,4 +40,4 @@
       "android"
     ]
   }
-}
+}

www/js/main.js

@@ -55,6 +55,52 @@ router.on("pageInit", function (pagedata) {
     });
 });
 
+/**
+ * Check if the server is alive.
+ * @param {function} callback
+ * @returns {undefined}
+ */
+function isServerAlive(callback) {
+    callAPIRawResponse("ping", {
+        username: localStorage.getItem("username"),
+        password: localStorage.getItem("password")
+    }, function (data) {
+        callback(true);
+    }, function (msg, xhr) {
+        app.preloader.hide();
+        if (xhr.status == 401) {
+            callback(true);
+        } else if (xhr.status == 400) {
+            callback(true);
+        } else {
+            callback(false);
+        }
+    });
+}
+
+/**
+ * Compare two version strings.
+ * http://stackoverflow.com/a/16187766/2534036
+ * @param {string} a
+ * @param {string} b
+ * @returns a number < 0 if a < b, a number > 0 if a > b, 0 if a = b
+ */
+function compareVersions(a, b) {
+    var i, diff;
+    var regExStrip0 = /(\.0+)+$/;
+    var segmentsA = a.replace(regExStrip0, '').split('.');
+    var segmentsB = b.replace(regExStrip0, '').split('.');
+    var l = Math.min(segmentsA.length, segmentsB.length);
+
+    for (i = 0; i < l; i++) {
+        diff = parseInt(segmentsA[i], 10) - parseInt(segmentsB[i], 10);
+        if (diff) {
+            return diff;
+        }
+    }
+    return segmentsA.length - segmentsB.length;
+}
+
 /**
  * Check if the saved username and password are valid.
  * @param {function} callback A function that will be called with a boolean argument indicating validity.
@@ -79,22 +125,39 @@ function checkLogin(callback) {
 if (localStorage.getItem("configured") == null) {
     router.navigate("/signin");
 } else {
-    checkLogin(function (valid) {
-        if (valid) {
-            callAPI("playerexists", {
+    isServerAlive(function (yes) {
+        if (yes) {
+            callAPI("version", {
                 username: localStorage.getItem("username"),
                 password: localStorage.getItem("password")
-            }, function (resp) {
-                if (resp.exists == true) {
-                    router.navigate("/home");
-                } else {
-                    router.navigate("/chooseteam");
-                }
-            }, function (msg) {
-                router.navigate("/signin");
+            }, function (data) {
+                $.getJSON("package.json", {}, function (local) {
+                    if (compareVersions(local.version, data.version) < 0) {
+                        router.navigate("/upgrade");
+                    } else {
+                        checkLogin(function (valid) {
+                            if (valid) {
+                                callAPI("playerexists", {
+                                    username: localStorage.getItem("username"),
+                                    password: localStorage.getItem("password")
+                                }, function (resp) {
+                                    if (resp.exists == true) {
+                                        router.navigate("/home");
+                                    } else {
+                                        router.navigate("/chooseteam");
+                                    }
+                                }, function (msg) {
+                                    router.navigate("/signin");
+                                });
+                            } else {
+                                router.navigate("/signin");
+                            }
+                        });
+                    }
+                });
             });
         } else {
-            router.navigate("/signin");
+            router.navigate("/connection");
         }
     });
 }

www/package.json

@@ -1,13 +1,13 @@
 {
-  "name": "TerranQuest-Web",
-  "version": "2.0.0",
-  "main": "index.js",
-  "license": "MPL-2.0",
-  "dependencies": {
-    "@fortawesome/fontawesome-free": "^5.8.1",
-    "framework7": "^4.3.0",
-    "jquery": "^3.4.0",
-    "mapbox-gl": "^0.54.0",
-    "three": "^0.104.0"
-  }
+    "name": "TerranQuest-Web",
+    "version": "2.0.0",
+    "main": "index.js",
+    "license": "MPL-2.0",
+    "dependencies": {
+        "@fortawesome/fontawesome-free": "^5.8.1",
+        "framework7": "^4.3.0",
+        "jquery": "^3.4.0",
+        "mapbox-gl": "^0.54.0",
+        "three": "^0.104.0"
+    }
 }

www/pages/connection.html

@@ -0,0 +1,25 @@
+<!-- This Source Code Form is subject to the terms of the Mozilla Public
+   - License, v. 2.0. If a copy of the MPL was not distributed with this
+   - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
+
+<div class="page" data-name="connection">
+
+    <div class="navbar">
+        <div class="navbar-inner">
+            <div class="title">No Connection</div>
+        </div>
+    </div>
+
+
+    <div class="page-content">
+
+        <div class="block text-center">
+            <p>TerranQuest can't connect to the game server.
+                <br />
+                <span class="button button-outline button-large button-raised margin-top" onclick="restartApplication()">Try Again</span>
+            </p>
+        </div>
+
+    </div>
+
+</div>

www/pages/upgrade.html

@@ -0,0 +1,23 @@
+<!-- This Source Code Form is subject to the terms of the Mozilla Public
+   - License, v. 2.0. If a copy of the MPL was not distributed with this
+   - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
+
+<div class="page" data-name="upgrade">
+
+    <div class="navbar">
+        <div class="navbar-inner">
+            <div class="title">Upgrade Required</div>
+        </div>
+    </div>
+
+
+    <div class="page-content">
+
+        <div class="block text-center">
+            <p>This version of TerranQuest is too old to work properly with the
+                game server.</p>
+        </div>
+
+    </div>
+
+</div>

www/routes.js

@@ -57,6 +57,16 @@ var routes = [
             }
         }
     },
+    {
+        path: '/upgrade',
+        url: './pages/upgrade.html',
+        name: 'upgrade'
+    },
+    {
+        path: '/connection',
+        url: './pages/connection.html',
+        name: 'connection'
+    },
     {
         path: '/settings',
         name: 'settings',