[Bugfix][Server] Add WMS SLD parameter support

Fixed #19795 QGIS Server 3 / WMS: the SLD parameter support has been removed

To reactivate SLD parameter support, we add a new conversion capability in server parameter `toUrl`. And the capabilty to load the content associted to an URL.

Then if the SLD parameter is defined, the content is loaded and the SLD_BODY is set.

python/server/auto_generated/qgsserverparameters.sip.in

@@ -138,6 +138,28 @@ Converts the parameter into a color.
 :param ok: True if there's no error during the conversion, false otherwise
 
 :return: A color
+%End
+
+    QUrl toUrl( bool &ok ) const;
+%Docstring
+Converts the parameter into an url.
+
+:param ok: True if there's no error during the conversion, false otherwise
+
+:return: An url
+
+.. versionadded:: 3.4
+%End
+
+    QString loadUrl( bool &ok ) const;
+%Docstring
+Loads the data associated to the parameter converted into an url.
+
+:param ok: True if there's no error during the load, false otherwise
+
+:return: The content loaded
+
+.. versionadded:: 3.4
 %End
 
     static void raiseError( const QString &msg );

src/server/qgsrequesthandler.cpp

@@ -154,20 +154,6 @@ void QgsRequestHandler::setupParameters()
 {
   const QgsServerRequest::Parameters parameters = mRequest.parameters();
 
-  // SLD
-  QString value = parameters.value( QStringLiteral( "SLD" ) );
-  if ( !value.isEmpty() )
-  {
-    QgsMessageLog::logMessage( QStringLiteral( "http and ftp methods not supported with Qt5." ) );
-  }
-
-  // SLD_BODY
-  value = parameters.value( QStringLiteral( "SLD_BODY" ) );
-  if ( ! value.isEmpty() )
-  {
-    mRequest.setParameter( QStringLiteral( "SLD" ), value );
-  }
-
   //feature info format?
   QString infoFormat = parameters.value( QStringLiteral( "INFO_FORMAT" ) );
   if ( !infoFormat.isEmpty() )

src/server/qgsserverparameters.cpp

@@ -17,6 +17,12 @@
 
 #include "qgsserverparameters.h"
 #include "qgsserverexception.h"
+#include "qgsnetworkaccessmanager.h"
+#include "qgsmessagelog.h"
+#include <QUrl>
+#include <QNetworkReply>
+#include <QNetworkRequest>
+#include <QTextCodec>
 
 //
 // QgsServerParameterDefinition
@@ -200,6 +206,167 @@ QgsRectangle QgsServerParameterDefinition::toRectangle( bool &ok ) const
   return extent;
 }
 
+QString QgsServerParameterDefinition::loadUrl( bool &ok ) const
+{
+  ok = true;
+
+  // Get URL
+  QUrl url = toUrl( ok );
+  if ( !ok )
+  {
+    return QString();
+  }
+
+  // Do the request
+  QNetworkReply *reply = nullptr;
+  // The following code blocks until the file is downloaded...
+  // with max redirections fixed to 5
+  int countRedirections = 0;
+  QDateTime start = QDateTime::currentDateTime();
+  while ( 1 )
+  {
+    QgsMessageLog::logMessage( QStringLiteral( "Request started [url: %2]" ).arg( url.toString() ) );
+    QNetworkRequest request( url );
+    request.setAttribute( QNetworkRequest::CacheLoadControlAttribute, QNetworkRequest::PreferCache );
+    request.setAttribute( QNetworkRequest::CacheSaveControlAttribute, true );
+
+    reply = QgsNetworkAccessManager::instance()->get( request );
+
+    // wait until the SLD download finished
+    while ( !reply->isFinished() )
+    {
+      if ( start.secsTo( QDateTime::currentDateTime() ) >= 5 * 60 )
+        break;
+      QCoreApplication::processEvents( QEventLoop::ExcludeUserInputEvents, 500 );
+    }
+
+    if ( !reply->isFinished() )
+    {
+      ok = false;
+      break;
+    }
+
+
+    if ( reply->error() != QNetworkReply::NoError )
+    {
+      ok = false;
+      QgsMessageLog::logMessage( QStringLiteral( "Request failed [error: %1 - url: %2]" ).arg( reply->errorString(), reply->url().toString() ) );
+      break;
+    }
+
+    QVariant redirect = reply->attribute( QNetworkRequest::RedirectionTargetAttribute );
+    if ( redirect.isNull() )
+    {
+      break;
+    }
+
+    // max redirections
+    countRedirections++;
+    if ( countRedirections >= 5 )
+    {
+      ok = false;
+      break;
+    }
+
+    // do a new request to the redirect url
+    url = redirect.toUrl();
+    reply->deleteLater();
+  }
+
+  if ( !reply->isFinished() )
+  {
+    ok = false;
+    QgsMessageLog::logMessage( QStringLiteral( "Request timeout [redirections: %1 - url: %2]" ).arg( countRedirections ).arg( mValue.toString() ) );
+
+    reply->abort();
+    reply->deleteLater();
+
+    return QString();
+  }
+
+  if ( countRedirections >= 5 )
+  {
+    ok = false;
+    QgsMessageLog::logMessage( QStringLiteral( "Request failed [max redirection raised - url: %1]" ).arg( mValue.toString() ) );
+
+    reply->deleteLater();
+    return QString();
+  }
+
+  QVariant status = reply->attribute( QNetworkRequest::HttpStatusCodeAttribute );
+  if ( !status.isNull() && status.toInt() >= 400 )
+  {
+    ok = false;
+    QVariant phrase = reply->attribute( QNetworkRequest::HttpReasonPhraseAttribute );
+    QgsMessageLog::logMessage( QStringLiteral( "Request error [status: %1 - reason phrase: %2] for %3" ).arg( status.toInt() ).arg( phrase.toString(), reply->url().toString() ) );
+
+    reply->deleteLater();
+    return QString();
+  }
+
+  if ( reply->error() != QNetworkReply::NoError )
+  {
+    ok = false;
+
+    reply->deleteLater();
+    return QString();
+  }
+
+  // read content
+  QByteArray ba = reply->readAll();
+  reply->deleteLater();
+
+  ok = ( !ba.isEmpty() );
+
+  //QTextCodec::codecForHtml fails to detect "<meta charset="utf-8"/>" type tags
+  //see https://bugreports.qt.io/browse/QTBUG-41011
+  //so test for that ourselves
+
+  //basic check
+  QTextCodec *codec = QTextCodec::codecForUtfText( ba, nullptr );
+  if ( !codec )
+  {
+    //check for meta charset tag
+    QByteArray header = ba.left( 1024 ).toLower();
+    int pos = header.indexOf( "meta charset=" );
+    if ( pos != -1 )
+    {
+      pos += int( strlen( "meta charset=" ) ) + 1;
+      int pos2 = header.indexOf( '\"', pos );
+      QByteArray cs = header.mid( pos, pos2 - pos );
+      codec = QTextCodec::codecForName( cs );
+    }
+  }
+
+  if ( !codec )
+  {
+    //fallback to QTextCodec::codecForHtml
+    codec = QTextCodec::codecForHtml( ba, codec );
+  }
+
+  if ( !codec )
+  {
+    //no luck, default to utf-8
+    codec = QTextCodec::codecForName( "UTF-8" );
+  }
+
+  return codec->toUnicode( ba );
+}
+
+QUrl QgsServerParameterDefinition::toUrl( bool &ok ) const
+{
+  ok = true;
+  QUrl val;
+
+  if ( !mValue.toString().isEmpty() )
+  {
+    val = mValue.toUrl();
+  }
+
+  ok = ( !val.isEmpty() && val.isValid() );
+  return val;
+}
+
 int QgsServerParameterDefinition::toInt( bool &ok ) const
 {
   ok = true;

src/server/qgsserverparameters.h

@@ -137,6 +137,22 @@ class SERVER_EXPORT QgsServerParameterDefinition
      */
     QColor toColor( bool &ok ) const;
 
+    /**
+     * Converts the parameter into an url.
+     * \param ok True if there's no error during the conversion, false otherwise
+     * \returns An url
+     * \since QGIS 3.4
+     */
+    QUrl toUrl( bool &ok ) const;
+
+    /**
+     * Loads the data associated to the parameter converted into an url.
+     * \param ok True if there's no error during the load, false otherwise
+     * \returns The content loaded
+     * \since QGIS 3.4
+     */
+    QString loadUrl( bool &ok ) const;
+
     /**
      * Raises an exception in case of an invalid parameters.
      * \param msg The message describing the exception

src/server/services/wms/qgswmsparameters.cpp

@@ -19,6 +19,7 @@
 #include "qgsdatasourceuri.h"
 #include "qgsmessagelog.h"
 #include <iostream>
+#include <QUrl>
 
 namespace QgsWms
 {
@@ -85,6 +86,37 @@ namespace QgsWms
     return val;
   }
 
+  QString QgsWmsParameter::loadUrl() const
+  {
+    // Check URL -- it will be used in error messages
+    const QUrl url = toUrl();
+
+    bool ok = false;
+    const QString content = QgsServerParameterDefinition::loadUrl( ok );
+
+    if ( !ok )
+    {
+      const QString msg = QString( "%1 request error for %2" ).arg( name( mName ), url.toString() );
+      QgsMessageLog::logMessage( msg );
+      QgsServerParameterDefinition::raiseError( msg );
+    }
+
+    return content;
+  }
+
+  QUrl QgsWmsParameter::toUrl() const
+  {
+    bool ok = false;
+    const QUrl url = QgsServerParameterDefinition::toUrl( ok );
+
+    if ( !ok )
+    {
+      raiseError();
+    }
+
+    return url;
+  }
+
   QColor QgsWmsParameter::toColor() const
   {
     bool ok = false;
@@ -336,6 +368,9 @@ namespace QgsWms
     const QgsWmsParameter pSld( QgsWmsParameter::SLD );
     save( pSld );
 
+    const QgsWmsParameter pSldBody( QgsWmsParameter::SLD_BODY );
+    save( pSldBody );
+
     const QgsWmsParameter pLayer( QgsWmsParameter::LAYER );
     save( pLayer );
 
@@ -470,6 +505,16 @@ namespace QgsWms
     : QgsWmsParameters()
   {
     load( parameters.urlQuery() );
+
+    const QString sld = mWmsParameters[ QgsWmsParameter::SLD ].toString();
+    if ( !sld.isEmpty() )
+    {
+      const QString sldBody = mWmsParameters[ QgsWmsParameter::SLD ].loadUrl();
+      if ( !sldBody.isEmpty() )
+      {
+        loadParameter( QgsWmsParameter::name( QgsWmsParameter::SLD_BODY ), sldBody );
+      }
+    }
   }
 
   bool QgsWmsParameters::loadParameter( const QString &key, const QString &value )
@@ -1159,9 +1204,9 @@ namespace QgsWms
     return mWmsParameters[ QgsWmsParameter::WMS_PRECISION ].toInt();
   }
 
-  QString QgsWmsParameters::sld() const
+  QString QgsWmsParameters::sldBody() const
   {
-    return mWmsParameters[ QgsWmsParameter::SLD ].toString();
+    return mWmsParameters[ QgsWmsParameter::SLD_BODY ].toString();
   }
 
   QStringList QgsWmsParameters::filters() const

src/server/services/wms/qgswmsparameters.h

@@ -132,6 +132,7 @@ namespace QgsWms
         SYMBOLWIDTH,
         OPACITIES,
         SLD,
+        SLD_BODY,
         FI_POLYGON_TOLERANCE,
         FI_LINE_TOLERANCE,
         FI_POINT_TOLERANCE,
@@ -251,6 +252,22 @@ namespace QgsWms
        */
       QColor toColor() const;
 
+      /**
+       * Converts the parameter into an url.
+       * \returns An url
+       * \throws QgsBadRequestException Invalid parameter exception
+       * \since QGIS 3.4
+       */
+      QUrl toUrl() const;
+
+      /**
+       * Loads the data associated to the parameter converted into an url.
+       * \returns The content loaded
+       * \throws QgsBadRequestException Invalid parameter exception
+       * \since QGIS 3.4
+       */
+      QString loadUrl() const;
+
       /**
        * Raises an error in case of an invalid conversion.
        * \throws QgsBadRequestException Invalid parameter exception
@@ -377,10 +394,10 @@ namespace QgsWms
       QgsRectangle bboxAsRectangle() const;
 
       /**
-       * Returns SLD if defined or an empty string.
-       * \returns sld
+       * Returns SLD_body if defined or an empty string.
+       * \returns sld body
        */
-      QString sld() const;
+      QString sldBody() const;
 
       /**
        * Returns the list of feature selection found in SELECTION parameter.

src/server/services/wms/qgswmsrenderer.cpp

@@ -170,7 +170,7 @@ namespace QgsWms
     QList<QgsMapLayer *> layers;
     QList<QgsWmsParametersLayer> params = mWmsParameters.layersParameters();
 
-    QString sld = mWmsParameters.sld();
+    QString sld = mWmsParameters.sldBody();
     if ( !sld.isEmpty() )
       layers = sldStylizedLayers( sld );
     else
@@ -312,7 +312,7 @@ namespace QgsWms
     restorer.reset( new QgsLayerRestorer( mNicknameLayers.values() ) );
 
     // init stylized layers according to LAYERS/STYLES or SLD
-    QString sld = mWmsParameters.sld();
+    QString sld = mWmsParameters.sldBody();
     if ( !sld.isEmpty() )
     {
       layers = sldStylizedLayers( sld );
@@ -661,7 +661,7 @@ namespace QgsWms
     restorer.reset( new QgsLayerRestorer( mNicknameLayers.values() ) );
 
     // init stylized layers according to LAYERS/STYLES or SLD
-    QString sld = mWmsParameters.sld();
+    QString sld = mWmsParameters.sldBody();
     if ( !sld.isEmpty() )
     {
       layers = sldStylizedLayers( sld );
@@ -749,7 +749,7 @@ namespace QgsWms
     restorer.reset( new QgsLayerRestorer( mNicknameLayers.values() ) );
 
     // init stylized layers according to LAYERS/STYLES or SLD
-    QString sld = mWmsParameters.sld();
+    QString sld = mWmsParameters.sldBody();
     if ( !sld.isEmpty() )
     {
       layers = sldStylizedLayers( sld );
@@ -903,7 +903,7 @@ namespace QgsWms
     restorer.reset( new QgsLayerRestorer( mNicknameLayers.values() ) );
 
     // init stylized layers according to LAYERS/STYLES or SLD
-    QString sld = mWmsParameters.sld();
+    QString sld = mWmsParameters.sldBody();
     if ( !sld.isEmpty() )
       layers = sldStylizedLayers( sld );
     else

tests/src/python/test_qgsserver_wms_getmap.py

@@ -1131,7 +1131,7 @@ class TestQgsServerWMSGetMap(QgsServerTestBase):
             "REQUEST": "GetMap",
             "VERSION": "1.1.1",
             "SERVICE": "WMS",
-            "SLD": "<?xml version=\"1.0\" encoding=\"UTF-8\"?><StyledLayerDescriptor xmlns=\"http://www.opengis.net/sld\" xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" xmlns:ogc=\"http://www.opengis.net/ogc\" xsi:schemaLocation=\"http://www.opengis.net/sld http://schemas.opengis.net/sld/1.1.0/StyledLayerDescriptor.xsd\" version=\"1.1.0\" xmlns:se=\"http://www.opengis.net/se\" xmlns:xlink=\"http://www.w3.org/1999/xlink\"> <NamedLayer> <se:Name>db_point</se:Name> <UserStyle> <se:Name>db_point_style</se:Name> <se:FeatureTypeStyle> <se:Rule> <se:Name>Single symbol</se:Name> <ogc:Filter xmlns:ogc=\"http://www.opengis.net/ogc\"> <ogc:PropertyIsEqualTo> <ogc:PropertyName>gid</ogc:PropertyName> <ogc:Literal>1</ogc:Literal> </ogc:PropertyIsEqualTo> </ogc:Filter> <se:PointSymbolizer uom=\"http://www.opengeospatial.org/se/units/metre\"> <se:Graphic> <se:Mark> <se:WellKnownName>square</se:WellKnownName> <se:Fill> <se:SvgParameter name=\"fill\">5e86a1</se:SvgParameter> </se:Fill> <se:Stroke> <se:SvgParameter name=\"stroke\">000000</se:SvgParameter> </se:Stroke> </se:Mark> <se:Size>0.007</se:Size> </se:Graphic> </se:PointSymbolizer> </se:Rule> </se:FeatureTypeStyle> </UserStyle> </NamedLayer> </StyledLayerDescriptor>",
+            "SLD_BODY": "<?xml version=\"1.0\" encoding=\"UTF-8\"?><StyledLayerDescriptor xmlns=\"http://www.opengis.net/sld\" xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" xmlns:ogc=\"http://www.opengis.net/ogc\" xsi:schemaLocation=\"http://www.opengis.net/sld http://schemas.opengis.net/sld/1.1.0/StyledLayerDescriptor.xsd\" version=\"1.1.0\" xmlns:se=\"http://www.opengis.net/se\" xmlns:xlink=\"http://www.w3.org/1999/xlink\"> <NamedLayer> <se:Name>db_point</se:Name> <UserStyle> <se:Name>db_point_style</se:Name> <se:FeatureTypeStyle> <se:Rule> <se:Name>Single symbol</se:Name> <ogc:Filter xmlns:ogc=\"http://www.opengis.net/ogc\"> <ogc:PropertyIsEqualTo> <ogc:PropertyName>gid</ogc:PropertyName> <ogc:Literal>1</ogc:Literal> </ogc:PropertyIsEqualTo> </ogc:Filter> <se:PointSymbolizer uom=\"http://www.opengeospatial.org/se/units/metre\"> <se:Graphic> <se:Mark> <se:WellKnownName>square</se:WellKnownName> <se:Fill> <se:SvgParameter name=\"fill\">5e86a1</se:SvgParameter> </se:Fill> <se:Stroke> <se:SvgParameter name=\"stroke\">000000</se:SvgParameter> </se:Stroke> </se:Mark> <se:Size>0.007</se:Size> </se:Graphic> </se:PointSymbolizer> </se:Rule> </se:FeatureTypeStyle> </UserStyle> </NamedLayer> </StyledLayerDescriptor>",
             "BBOX": "-16817707,-4710778,5696513,14587125",
             "WIDTH": "500",
             "HEIGHT": "500",
@@ -1231,7 +1231,7 @@ class TestQgsServerWMSGetMap(QgsServerTestBase):
             "SERVICE": "WMS",
             "VERSION": "1.1.1",
             "REQUEST": "GetMap",
-            "SLD": "<?xml version=\"1.0\" encoding=\"UTF-8\"?><StyledLayerDescriptor xmlns=\"http://www.opengis.net/sld\" xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" xmlns:ogc=\"http://www.opengis.net/ogc\" xsi:schemaLocation=\"http://www.opengis.net/sld http://schemas.opengis.net/sld/1.1.0/StyledLayerDescriptor.xsd\" version=\"1.1.0\" xmlns:se=\"http://www.opengis.net/se\" xmlns:xlink=\"http://www.w3.org/1999/xlink\"> <NamedLayer> <se:Name>CountryGroup</se:Name></NamedLayer> </StyledLayerDescriptor>",
+            "SLD_BODY": "<?xml version=\"1.0\" encoding=\"UTF-8\"?><StyledLayerDescriptor xmlns=\"http://www.opengis.net/sld\" xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" xmlns:ogc=\"http://www.opengis.net/ogc\" xsi:schemaLocation=\"http://www.opengis.net/sld http://schemas.opengis.net/sld/1.1.0/StyledLayerDescriptor.xsd\" version=\"1.1.0\" xmlns:se=\"http://www.opengis.net/se\" xmlns:xlink=\"http://www.w3.org/1999/xlink\"> <NamedLayer> <se:Name>CountryGroup</se:Name></NamedLayer> </StyledLayerDescriptor>",
             "STYLES": "",
             "FORMAT": "image/png",
             "BBOX": "-16817707,-4710778,5696513,14587125",