[FEATURE] load MVT layers from style URL only (#58663)

with support for multiple sources

src/app/qgisapp.cpp

@@ -93,6 +93,7 @@
 #include "maptools/qgsappmaptools.h"
 #include "qgsexpressioncontextutils.h"
 #include "qgsauxiliarystorage.h"
+#include "qgsvectortileutils.h"
 
 #include "qgsbrowserwidget.h"
 #include "annotations/qgsannotationitempropertieswidget.h"
@@ -2517,6 +2518,8 @@ QList< QgsMapLayer * > QgisApp::handleDropUriList( const QgsMimeDataUtils::UriLi
     {
       QgsTemporaryCursorOverride busyCursor( Qt::WaitCursor );
 
+      QgsVectorTileUtils::updateUriSources( uri );
+
       const QgsVectorTileLayer::LayerOptions options( QgsProject::instance()->transformContext() );
       QgsVectorTileLayer *layer = new QgsVectorTileLayer( uri, u.name, options );
       bool ok = false;

src/core/vectortile/qgsvectortilemvtdecoder.cpp

@@ -29,6 +29,7 @@
 #include "qgspolygon.h"
 
 #include <QPointer>
+#include <QNetworkRequest>
 
 
 QgsVectorTileMVTDecoder::QgsVectorTileMVTDecoder( const QgsVectorTileMatrixSet &structure )

src/core/vectortile/qgsvectortilemvtdecoder.h

@@ -28,6 +28,7 @@ class QgsFeature;
 #include "qgsvectortilerenderer.h"
 #include "qgsvectortilematrixset.h"
 
+
 class QgsVectorTileRawData;
 
 /**

src/core/vectortile/qgsvectortileutils.cpp

@@ -18,6 +18,8 @@
 #include <math.h>
 
 #include <QPolygon>
+#include <QJsonDocument>
+#include <QJsonArray>
 
 #include "qgscoordinatetransform.h"
 #include "qgsgeometrycollection.h"
@@ -32,10 +34,146 @@
 #include "qgsvectortilelayer.h"
 #include "qgsvectortilerenderer.h"
 #include "qgsmapboxglstyleconverter.h"
-#include "qgsnetworkaccessmanager.h"
 #include "qgssetrequestinitiator_p.h"
 #include "qgsblockingnetworkrequest.h"
 #include "qgsjsonutils.h"
+#include "qgsvectortileconnection.h"
+
+
+void QgsVectorTileUtils::updateUriSources( QString &uri, bool forceUpdate )
+{
+  QgsVectorTileProviderConnection::Data data = QgsVectorTileProviderConnection::decodedUri( uri );
+  if ( forceUpdate || ( data.url.isEmpty() && !data.styleUrl.isEmpty() ) )
+  {
+    const QMap<QString, QString> sources = QgsVectorTileUtils::parseStyleSourceUrl( data.styleUrl, data.httpHeaders, data.authCfg );
+    QMap<QString, QString>::const_iterator it = sources.constBegin();
+    int i = 0;
+    for ( ; it != sources.constEnd(); ++it )
+    {
+      i += 1;
+      QString urlKey = QStringLiteral( "url" );
+      QString nameKey = QStringLiteral( "urlName" );
+      if ( i > 1 )
+      {
+        urlKey.append( QString( "_%1" ).arg( i ) );
+        nameKey.append( QString( "_%1" ).arg( i ) );
+      }
+      uri.append( QString( "&%1=%2" ).arg( nameKey, it.key() ) );
+      uri.append( QString( "&%1=%2" ).arg( urlKey, it.value() ) );
+    }
+  }
+}
+
+QMap<QString, QString> QgsVectorTileUtils::parseStyleSourceUrl( const QString &styleUrl, const QgsHttpHeaders &headers, const QString &authCfg )
+{
+  QNetworkRequest nr;
+  nr.setUrl( QUrl( styleUrl ) );
+  headers.updateNetworkRequest( nr );
+
+  QgsBlockingNetworkRequest req;
+  req.setAuthCfg( authCfg );
+  QgsBlockingNetworkRequest::ErrorCode errCode = req.get( nr, false );
+  if ( errCode != QgsBlockingNetworkRequest::NoError )
+  {
+    QgsDebugError( QStringLiteral( "Request failed: " ) + styleUrl );
+    return QMap<QString, QString>();
+  }
+  QgsNetworkReplyContent reply = req.reply();
+
+  QJsonParseError err;
+  const QJsonDocument doc = QJsonDocument::fromJson( reply.content(), &err );
+  if ( doc.isNull() )
+  {
+    QgsDebugError( QStringLiteral( "Could not load style: %1" ).arg( err.errorString() ) );
+  }
+  else if ( !doc.isObject() )
+  {
+    QgsDebugError( QStringLiteral( "Could not read style, JSON object is expected" ) );
+  }
+  else
+  {
+    QMap<QString, QString> sources;
+    QJsonObject sourcesData = doc.object().value( QStringLiteral( "sources" ) ).toObject();
+    if ( sourcesData.count() == 0 )
+    {
+      QgsDebugError( QStringLiteral( "Could not read sources in the style" ) );
+    }
+    else
+    {
+      QJsonObject::const_iterator it = sourcesData.constBegin();
+      for ( ; it != sourcesData.constEnd(); ++it )
+      {
+        const QString sourceName = it.key();
+        const QJsonObject sourceData = it.value().toObject();
+        if ( sourceData.value( QStringLiteral( "type" ) ).toString() != QStringLiteral( "vector" ) )
+        {
+          // raster layers are handled separately
+          // ideally we should handle the sources here also, the same way than for vector
+          continue;
+        }
+        QVariantList tiles;
+        if ( sourceData.contains( QStringLiteral( "tiles" ) ) )
+        {
+          tiles = sourceData["tiles"].toArray().toVariantList();
+        }
+        else if ( sourceData.contains( QStringLiteral( "url" ) ) )
+        {
+          tiles = parseStyleSourceContentUrl( sourceData.value( QStringLiteral( "url" ) ).toString(), headers, authCfg );
+        }
+        else
+        {
+          QgsDebugError( QStringLiteral( "Could not read source %1" ).arg( sourceName ) );
+        }
+        if ( tiles.count() == 0 )
+        {
+          QgsDebugError( QStringLiteral( "Could not read source %1, not tiles found" ).arg( sourceName ) );
+        }
+        else
+        {
+          // take a random one from the list
+          // we might want to save the alternatives for a fallback later
+          sources.insert( sourceName, tiles[rand() % tiles.count()].toString() );
+        }
+      }
+      return sources;
+    }
+  }
+  return QMap<QString, QString>();
+}
+
+QVariantList QgsVectorTileUtils::parseStyleSourceContentUrl( const QString &sourceUrl, const QgsHttpHeaders &headers, const QString &authCfg )
+{
+  QNetworkRequest nr;
+  nr.setUrl( QUrl( sourceUrl ) );
+  headers.updateNetworkRequest( nr );
+
+  QgsBlockingNetworkRequest req;
+  req.setAuthCfg( authCfg );
+  QgsBlockingNetworkRequest::ErrorCode errCode = req.get( nr, false );
+  if ( errCode != QgsBlockingNetworkRequest::NoError )
+  {
+    QgsDebugError( QStringLiteral( "Request failed: " ) + sourceUrl );
+    return QVariantList();
+  }
+  QgsNetworkReplyContent reply = req.reply();
+
+  QJsonParseError err;
+  const QJsonDocument doc = QJsonDocument::fromJson( reply.content(), &err );
+  if ( doc.isNull() )
+  {
+    QgsDebugError( QStringLiteral( "Could not load style: %1" ).arg( err.errorString() ) );
+  }
+  else if ( !doc.isObject() )
+  {
+    QgsDebugError( QStringLiteral( "Could not read style, JSON object is expected" ) );
+  }
+  else
+  {
+    return doc.object().value( QStringLiteral( "tiles" ) ).toArray().toVariantList();
+  }
+  return QVariantList();
+}
+
 
 
 QPolygon QgsVectorTileUtils::tilePolygon( QgsTileXYZ id, const QgsCoordinateTransform &ct, const QgsTileMatrix &tm, const QgsMapToPixel &mtp )

src/core/vectortile/qgsvectortileutils.h

@@ -23,6 +23,9 @@
 #include <QSet>
 #include <QVariantMap>
 
+#include "qgshttpheaders.h"
+
+
 class QPointF;
 class QPolygon;
 
@@ -48,6 +51,13 @@ class CORE_EXPORT QgsVectorTileUtils
 {
   public:
 
+    /**
+     * Parses the style URL to update the source URLs in the \a uri.
+     * If \a forceUpdate is TRUE, any existing source will be updated.
+     * \since QGIS 3.40
+     */
+    static void updateUriSources( QString &uri SIP_OUT, bool forceUpdate = false );
+
     //! Orders tile requests according to the distance from view center (given in tile matrix coords)
     static void sortTilesByDistanceFromCenter( QVector<QgsTileXYZ> &tiles, QPointF center );
 
@@ -92,6 +102,16 @@ class CORE_EXPORT QgsVectorTileUtils
      * \param styleUrl optional the style url
      */
     static void loadSprites( const QVariantMap &styleDefinition, QgsMapBoxGlStyleConversionContext &context, const QString &styleUrl = QString() );
+
+  private:
+    //! Parses the style URL to get a list of named source URLs.
+    static QMap<QString, QString> parseStyleSourceUrl( const QString &styleUrl, const QgsHttpHeaders &headers = QgsHttpHeaders(), const QString &authCfg = QString() );
+
+    //! Returns the tiles URLs of a source
+    static QVariantList parseStyleSourceContentUrl( const QString &sourceUrl, const QgsHttpHeaders &headers = QgsHttpHeaders(), const QString &authCfg = QString() );
+
+    friend class TestQgsVectorTileUtils;
+
 };
 
 #endif // QGSVECTORTILEUTILS_H

src/gui/vectortile/qgsvectortileconnectiondialog.cpp

@@ -17,18 +17,22 @@
 #include "qgsvectortileconnection.h"
 #include "qgsgui.h"
 #include "qgshelp.h"
+#include "qgssettingsenumflageditorwidgetwrapper.h"
 
 #include <QMessageBox>
 #include <QPushButton>
 
 ///@cond PRIVATE
 
+
 QgsVectorTileConnectionDialog::QgsVectorTileConnectionDialog( QWidget *parent )
   : QDialog( parent )
 {
   setupUi( this );
   QgsGui::enableAutoGeometryRestore( this );
 
+  mEditUrl->setPlaceholderText( tr( "URL(s) can be determined from the style." ) );
+
   // Behavior for min and max zoom checkbox
   connect( mCheckBoxZMin, &QCheckBox::toggled, mSpinZMin, &QSpinBox::setEnabled );
   connect( mCheckBoxZMax, &QCheckBox::toggled, mSpinZMax, &QSpinBox::setEnabled );
@@ -41,6 +45,7 @@ QgsVectorTileConnectionDialog::QgsVectorTileConnectionDialog( QWidget *parent )
   } );
   connect( mEditName, &QLineEdit::textChanged, this, &QgsVectorTileConnectionDialog::updateOkButtonState );
   connect( mEditUrl, &QLineEdit::textChanged, this, &QgsVectorTileConnectionDialog::updateOkButtonState );
+  connect( mEditStyleUrl, &QLineEdit::textChanged, this, &QgsVectorTileConnectionDialog::updateOkButtonState );
 }
 
 void QgsVectorTileConnectionDialog::setConnection( const QString &name, const QString &uri )
@@ -85,10 +90,11 @@ QString QgsVectorTileConnectionDialog::connectionName() const
 
 void QgsVectorTileConnectionDialog::updateOkButtonState()
 {
-  const bool enabled = !mEditName->text().isEmpty() && !mEditUrl->text().isEmpty();
+  const bool enabled = !mEditName->text().isEmpty() && ( !mEditUrl->text().isEmpty() || !mEditStyleUrl->text().isEmpty() );
   buttonBox->button( QDialogButtonBox::Ok )->setEnabled( enabled );
 }
 
+
 void QgsVectorTileConnectionDialog::accept()
 {
   if ( mCheckBoxZMin->isChecked() && mCheckBoxZMax->isChecked() && mSpinZMax->value() < mSpinZMin->value() )

src/gui/vectortile/qgsvectortileconnectiondialog.h

@@ -23,11 +23,21 @@
 
 #include "ui_qgsvectortileconnectiondialog.h"
 
+#include "qgssettingsentryenumflag.h"
 
 class QgsVectorTileConnectionDialog : public QDialog, public Ui::QgsVectorTileConnectionDialog
 {
     Q_OBJECT
   public:
+    enum class LoadingMode : int
+    {
+      Url,
+      Style
+    };
+    Q_ENUM( LoadingMode )
+
+    static const QgsSettingsEntryEnumFlag<QgsVectorTileConnectionDialog::LoadingMode> *settingsLastLoadingMode;
+
     explicit QgsVectorTileConnectionDialog( QWidget *parent = nullptr );
 
     void setConnection( const QString &name, const QString &uri );
@@ -39,7 +49,6 @@ class QgsVectorTileConnectionDialog : public QDialog, public Ui::QgsVectorTileCo
 
   private slots:
     void updateOkButtonState();
-
 };
 
 ///@endcond