Allow use of custom data structures as router callback arguments

Change-Id: I6dcc66a95b72bb461f237cade0352a0177065227
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>
Reviewed-by: Jesus Fernandez <Jesus.Fernandez@qt.io>
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>

4 files changed, 114 insertions, 6 deletions

diff --git a/src/httpserver/qhttpserverrouter.cpp b/src/httpserver/qhttpserverrouter.cpp
index 8aeca62..1dc924c 100644
--- a/src/httpserver/qhttpserverrouter.cpp
+++ b/src/httpserver/qhttpserverrouter.cpp
@@ -97,6 +97,44 @@ static const QMap<int, QLatin1String> defaultConverters = {
     \endcode
 */
 
+/*! \fn template <typename Type> bool QHttpServerRouter::addConverter(const QLatin1String &regexp)
+
+    Adds a new converter for type \e Type matching regular expression \a regexp.
+
+    Automatically try to register an implicit converter from QString to \e Type.
+    If there is already a converter of type \e Type, that converter's regexp
+    is replaced with \a regexp.
+
+    \code
+    struct CustomArg {
+        int data = 10;
+
+        CustomArg() {} ;
+        CustomArg(const QString &urlArg) : data(urlArg.toInt()) {}
+    };
+    Q_DECLARE_METATYPE(CustomArg);
+
+    QHttpServerRouter router;
+    router.addConverter<CustomArg>(QLatin1String("[+-]?\\d+"));
+
+    auto pageView = [] (const CustomArg &customArg) {
+        qDebug("data: %d", customArg.data);
+    };
+    using ViewHandler = decltype(pageView);
+
+    auto rule = new QHttpServerRouterRule(
+        "/<arg>/<arg>/log",
+        [&router, &pageView] (QRegularExpressionMatch &match,
+                              const QHttpServerRequest &request,
+                              QTcpSocket *socket) {
+        // Bind and call viewHandler with match's captured string and quint32:
+        router.bindCaptured(pageView, match)();
+    });
+
+    router.addRule<ViewHandler>(rule);
+    \endcode
+*/
+
 /*! \fn template <typename ViewHandler, typename ViewTraits = QHttpServerRouterViewTraits<ViewHandler>> bool QHttpServerRouter::addRule(QHttpServerRouterRule *rule)
 
     Adds a new \a rule.
@@ -134,14 +172,16 @@ static const QMap<int, QLatin1String> defaultConverters = {
     \code
     QHttpServerRouter router;
 
-    auto pageView = [] (const QString &page, const quint32 num) { };
+    auto pageView = [] (const QString &page, const quint32 num) {
+        qDebug("page: %s, num: %d", qPrintable(page), num);
+    };
     using ViewHandler = decltype(pageView);
 
     auto rule = new QHttpServerRouterRule(
         "/<arg>/<arg>/log",
-        [&router] (QRegularExpressionMatch &match,
-                   const QHttpServerRequest &request,
-                   QTcpSocket *socket) {
+        [&router, &pageView] (QRegularExpressionMatch &match,
+                              const QHttpServerRequest &request,
+                              QTcpSocket *socket) {
         // Bind and call viewHandler with match's captured string and quint32:
         router.bindCaptured(pageView, match)();
     });
diff --git a/src/httpserver/qhttpserverrouter.h b/src/httpserver/qhttpserverrouter.h
index 13b2a09..522562c 100644
--- a/src/httpserver/qhttpserverrouter.h
+++ b/src/httpserver/qhttpserverrouter.h
@@ -72,6 +72,19 @@ public:
     QHttpServerRouter();
     ~QHttpServerRouter();
 
+    template<typename Type>
+    bool addConverter(const QLatin1String &regexp) {
+        static_assert(QMetaTypeId2<Type>::Defined,
+                      "Type is not registered with Qt's meta-object system: "
+                      "please apply Q_DECLARE_METATYPE() to it");
+
+        if (!QMetaType::registerConverter<QString, Type>())
+            return false;
+
+        addConverter(qMetaTypeId<Type>(), regexp);
+        return true;
+    }
+
     void addConverter(const int type, const QLatin1String &regexp);
     void removeConverter(const int);
     void clearConverters();
diff --git a/src/httpserver/qhttpserverrouterrule.cpp b/src/httpserver/qhttpserverrouterrule.cpp
index 032287a..d486218 100644
--- a/src/httpserver/qhttpserverrouterrule.cpp
+++ b/src/httpserver/qhttpserverrouterrule.cpp
@@ -175,10 +175,19 @@ bool QHttpServerRouterRule::createPathRegexp(const std::initializer_list<int> &m
     QString pathRegexp = d->pathPattern;
     const QLatin1String arg("<arg>");
     for (auto type : metaTypes) {
+        if (type >= QMetaType::User
+            && !QMetaType::hasRegisteredConverterFunction(qMetaTypeId<QString>(), type)) {
+            qCWarning(lcRouterRule) << QMetaType::typeName(type)
+                                    << "has not registered a converter to QString."
+                                    << "Use QHttpServerRouter::addConveter<Type>(converter).";
+            return false;
+        }
+
         auto it = converters.constFind(type);
         if (it == converters.end()) {
-            qCWarning(lcRouterRule) << "can not find converter for type:" << type;
-            continue;
+            qCWarning(lcRouterRule) << "can not find converter for type:"
+                                    << QMetaType::typeName(type);
+            return false;
         }
 
         if (it->isEmpty())
diff --git a/tests/auto/qhttpserver/tst_qhttpserver.cpp b/tests/auto/qhttpserver/tst_qhttpserver.cpp
index 41bae53..6193fb5 100644
--- a/tests/auto/qhttpserver/tst_qhttpserver.cpp
+++ b/tests/auto/qhttpserver/tst_qhttpserver.cpp
@@ -40,6 +40,7 @@
 #include <QtCore/qstring.h>
 #include <QtCore/qlist.h>
 #include <QtCore/qbytearray.h>
+#include <QtCore/qdatetime.h>
 
 #include <QtNetwork/qnetworkaccessmanager.h>
 #include <QtNetwork/qnetworkreply.h>
@@ -84,12 +85,20 @@ private slots:
     void routeGet();
     void routePost_data();
     void routePost();
+    void invalidRouterArguments();
 
 private:
     QHttpServer httpserver;
     QString urlBase;
 };
 
+struct CustomArg {
+    int data = 10;
+
+    CustomArg() {} ;
+    CustomArg(const QString &urlArg) : data(urlArg.toInt()) {}
+};
+
 void tst_QHttpServer::initTestCase()
 {
     httpserver.route("/test", [] (QHttpServerResponder &&responder) {
@@ -151,6 +160,12 @@ void tst_QHttpServer::initTestCase()
     });
 
     urlBase = QStringLiteral("http://localhost:%1%2").arg(httpserver.listen());
+
+
+    httpserver.router()->addConverter<CustomArg>(QLatin1String("[+-]?\\d+"));
+    httpserver.route("/check-custom-type/", [] (const CustomArg &customArg) {
+        return QString("data = %1").arg(customArg.data);
+    });
 }
 
 void tst_QHttpServer::routeGet_data()
@@ -278,6 +293,13 @@ void tst_QHttpServer::routeGet_data()
         << 200
         << "text/html"
         << "Custom router rule: 10, key=12";
+
+    QTest::addRow("check custom type, data=1")
+        << "/check-custom-type/1"
+        << 200
+        << "text/html"
+        << "data = 1";
+
 }
 
 void tst_QHttpServer::routeGet()
@@ -333,8 +355,32 @@ void tst_QHttpServer::routePost()
     QCOMPARE(reply->readAll(), body);
 }
 
+struct CustomType {
+    CustomType() {}
+    CustomType(const QString &) {}
+};
+
+void tst_QHttpServer::invalidRouterArguments()
+{
+    QCOMPARE(
+        httpserver.route("/datetime/", [] (const QDateTime &datetime) {
+            return QString("datetime: %1").arg(datetime.toString());
+        }),
+        false);
+
+    QCOMPARE(
+        httpserver.route("/implicit-conversion-to-qstring-has-no-registered/",
+                         [] (const CustomType &) {
+            return "";
+        }),
+        false);
+}
+
 QT_END_NAMESPACE
 
+Q_DECLARE_METATYPE(CustomArg);
+Q_DECLARE_METATYPE(CustomType);
+
 QTEST_MAIN(tst_QHttpServer)
 
 #include "tst_qhttpserver.moc"