Add feedback on login errors

There was no feedback on any login errors when a user provided a
wrong url, username, password or a disabled API. This commit
adds feedback to the user in this cases.

Fixes #15

qml/main.qml

@@ -21,6 +21,7 @@ import QtQuick 2.3
 import QtQuick.Controls 1.3
 import QtQuick.Window 2.0
 import QtQuick.Layouts 1.1
+import QtQuick.Dialogs 1.1
 import Qt.labs.settings 1.0
 import TTRSS 1.0
 
@@ -210,14 +211,27 @@ ApplicationWindow {
         visible: !serverLogin.loggedIn()
 
         function login() {
-            console.log("FOO")
             serverLogin.login(serverUrl, userName, password)
         }
+
+    }
+
+    MessageDialog {
+        id: loginErrorAlert
+        title: "A login error occured"
+        text: serverLogin.loginError
+        onAccepted: visible = false
     }
 
     ServerLogin {
         id: serverLogin
         onSessionIdChanged: app.loggedIn()
+        onLoginErrorChanged: {
+            console.log("loginError:", loginError)
+            if(loginError.length > 0) {
+                loginErrorAlert.visible = true
+            }
+        }
     }
 
     Server {

src/tinytinyrsslogin.cpp

@@ -88,23 +88,35 @@ void TinyTinyRSSLogin::reply()
     QNetworkReply *reply = qobject_cast<QNetworkReply*>(sender());
 
     if (reply) {
+
         if (reply->error() == QNetworkReply::NoError) {
 
             QString jsonString = QString(reply->readAll());
             QJsonDocument json = QJsonDocument::fromJson(jsonString.toUtf8());
-            mSessionId = json.object().value("content").toObject().value("session_id").toString();
+            if(json.object().value("content").toObject().value("error").toString().length() > 0) {
 
-            emit sessionIdChanged(mSessionId);
+                mLoginError = json.object().value("content").toObject().value("error").toString();
+                qWarning() << mLoginError;
+                emit loginErrorChanged(mLoginError);
 
-            QSettings settings;
-            settings.setValue("sessionId", mSessionId);
-            settings.setValue("serverUrl", mServerUrl);
-            settings.sync();
+            } else {
+                mSessionId = json.object().value("content").toObject().value("session_id").toString();
 
+                emit sessionIdChanged(mSessionId);
+
+                QSettings settings;
+                settings.setValue("sessionId", mSessionId);
+                settings.setValue("serverUrl", mServerUrl);
+                settings.sync();
+            }
         } else {
-            int httpStatus = reply->attribute(QNetworkRequest::HttpStatusCodeAttribute).toInt();
-            //do some error management
-            qWarning() << "HTTP error: " << httpStatus << " :: " << reply->error();
+            mLoginError = "HTTP error: "
+                    + reply->attribute(QNetworkRequest::HttpStatusCodeAttribute).toString()
+                    + " :: "
+                    + reply->errorString();
+            qWarning() << mLoginError;
+
+            emit loginErrorChanged(mLoginError);
         }
         reply->deleteLater();
     }

src/tinytinyrsslogin.h

@@ -30,12 +30,14 @@ class TinyTinyRSSLogin : public QObject
     Q_OBJECT
     Q_PROPERTY(QString sessionId READ sessionId NOTIFY sessionIdChanged)
     Q_PROPERTY(QUrl serverUrl READ serverUrl)
+    Q_PROPERTY(QString loginError READ loginError NOTIFY loginErrorChanged)
 
 public:
     TinyTinyRSSLogin(QObject *parent = 0);
     ~TinyTinyRSSLogin();
     QString sessionId() const { return mSessionId; }
     QUrl serverUrl() const { return mServerUrl; }
+    QString loginError() const { return mLoginError; }
 
     Q_INVOKABLE bool loggedIn();
     Q_INVOKABLE void login(const QString serverUrl, const QString user, const QString password);
@@ -43,6 +45,7 @@ public:
 
 signals:
     void sessionIdChanged(QString);
+    void loginErrorChanged(QString);
 
 private slots:
     void reply();
@@ -50,6 +53,7 @@ private slots:
 private:
     QString mSessionId;
     QUrl mServerUrl;
+    QString mLoginError;
     QNetworkAccessManager *mNetworkManager;
 };