Server: throw exception if one or more layers are not available. Proj…

…ects with missing layers are not cached, the layer may become available in future if e.g. the db connection has been temporarly interupted

src/server/CMakeLists.txt

@@ -40,6 +40,7 @@ SET(QGIS_SERVER_SRCS
   qgsserviceregistry.cpp
   qgsfeaturefilterprovidergroup.cpp
   qgsfeaturefilter.cpp
+  qgsstorebadlayerinfo.cpp
 )
 
 SET (QGIS_SERVER_HDRS

src/server/qgsconfigcache.cpp

@@ -17,6 +17,8 @@
 
 #include "qgsconfigcache.h"
 #include "qgsmessagelog.h"
+#include "qgsserverexception.h"
+#include "qgsstorebadlayerinfo.h"
 
 #include <QFile>
 
@@ -40,8 +42,14 @@ const QgsProject *QgsConfigCache::project( const QString &path )
   if ( ! mProjectCache[ path ] )
   {
     std::unique_ptr<QgsProject> prj( new QgsProject() );
+    QgsStoreBadLayerInfo *badLayerHandler = new QgsStoreBadLayerInfo();
+    prj->setBadLayerHandler( badLayerHandler );
     if ( prj->read( path ) )
     {
+      if ( badLayerHandler->badLayers().size() > 0 )
+      {
+        throw QgsServerException( QStringLiteral( "Layer(s) not valid" ) );
+      }
       mProjectCache.insert( path, prj.release() );
       mFileSystemWatcher.addPath( path );
     }

src/server/qgsstorebadlayerinfo.cpp

@@ -0,0 +1,27 @@
+#include "qgsstorebadlayerinfo.h"
+#include <QDomElement>
+
+QgsStoreBadLayerInfo::QgsStoreBadLayerInfo(): QgsProjectBadLayerHandler()
+{
+}
+
+QgsStoreBadLayerInfo::~QgsStoreBadLayerInfo()
+{
+}
+
+void QgsStoreBadLayerInfo::handleBadLayers( const QList<QDomNode> &layers )
+{
+  mBadLayerIds.clear();
+  QList<QDomNode>::const_iterator it = layers.constBegin();
+  for ( ; it != layers.constEnd(); ++it )
+  {
+    if ( !it->isNull() )
+    {
+      QDomElement idElem = it->firstChildElement( "id" );
+      if ( !idElem.isNull() )
+      {
+        mBadLayerIds.append( idElem.text() );
+      }
+    }
+  }
+}

src/server/qgsstorebadlayerinfo.h

@@ -0,0 +1,32 @@
+#ifndef QGSSTOREBADLAYERINFO_H
+#define QGSSTOREBADLAYERINFO_H
+
+#include "qgsprojectbadlayerhandler.h"
+#include <QStringList>
+
+/**
+ * \ingroup server
+ * Stores layer ids of bad layers
+ */
+class QgsStoreBadLayerInfo: public QgsProjectBadLayerHandler
+{
+    public:
+        QgsStoreBadLayerInfo();
+        ~QgsStoreBadLayerInfo();
+        /**
+         * @brief handleBadLayers
+         * @param layers layer nodes
+         */
+        void handleBadLayers( const QList<QDomNode> &layers );
+
+        /**
+         * @brief badLayers
+         * @return ids of bad layers
+         */
+        QStringList badLayers() const { return mBadLayerIds; }
+
+    private:
+        QStringList mBadLayerIds;
+};
+
+#endif // QGSSTOREBADLAYERINFO_H