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Merge pull request #3148 from rouault/wfs_better_behaviour_with_wrong…

…_capability_extent

[WFS Provider] Implement workarounds to better behave when extent reported by capabilities is wrong
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rouault committed May 30, 2016
2 parents 86f6e7e + 2ac20c6 commit a023f55b9d0c5d26074564787eca431276fbe683
@@ -389,12 +389,6 @@ void QgsWFSFeatureDownloader::run( bool serializeFeatures, int maxFeatures )
connect( &mFeatureHitsAsyncRequest, SIGNAL( downloadFinished() ), &loop, SLOT( quit() ) );
}

QgsGmlStreamingParser::AxisOrientationLogic axisOrientationLogic( QgsGmlStreamingParser::Honour_EPSG_if_urn );
if ( mShared->mURI.ignoreAxisOrientation() )
{
axisOrientationLogic = QgsGmlStreamingParser::Ignore_EPSG;
}

bool interrupted = false;
bool truncatedResponse = false;
QSettings s;
@@ -404,32 +398,7 @@ void QgsWFSFeatureDownloader::run( bool serializeFeatures, int maxFeatures )
while ( true )
{
success = true;
QgsGmlStreamingParser* parser;
if ( mShared->mLayerPropertiesList.size() )
{
QList< QgsGmlStreamingParser::LayerProperties > layerPropertiesList;
Q_FOREACH ( QgsOgcUtils::LayerProperties layerProperties, mShared->mLayerPropertiesList )
{
QgsGmlStreamingParser::LayerProperties layerPropertiesOut;
layerPropertiesOut.mName = layerProperties.mName;
layerPropertiesOut.mGeometryAttribute = layerProperties.mGeometryAttribute;
layerPropertiesList << layerPropertiesOut;
}

parser = new QgsGmlStreamingParser( layerPropertiesList,
mShared->mFields,
mShared->mMapFieldNameToSrcLayerNameFieldName,
axisOrientationLogic,
mShared->mURI.invertAxisOrientation() );
}
else
{
parser = new QgsGmlStreamingParser( mShared->mURI.typeName(),
mShared->mGeometryAttribute,
mShared->mFields,
axisOrientationLogic,
mShared->mURI.invertAxisOrientation() );
}
QgsGmlStreamingParser* parser = mShared->createParser();

QUrl url( buildURL( mTotalDownloadedFeatureCount,
maxFeatures ? maxFeatures : mShared->mMaxFeatures, false ) );
@@ -59,6 +59,7 @@ QgsWFSProvider::QgsWFSProvider( const QString& uri, const QgsWFSCapabilities::Ca
{
mShared->mCaps = caps;
connect( mShared.data(), SIGNAL( raiseError( const QString& ) ), this, SLOT( pushErrorSlot( const QString& ) ) );
connect( mShared.data(), SIGNAL( extentUpdated() ), this, SIGNAL( fullExtentCalculated() ) );

if ( uri.isEmpty() )
{
@@ -684,7 +685,29 @@ QgsCoordinateReferenceSystem QgsWFSProvider::crs()

QgsRectangle QgsWFSProvider::extent()
{
return mExtent;
// Some servers return completely buggy extent in their capabilities response
// so mix it with the extent actually got from the downloaded features
QgsRectangle computedExtent( mShared->computedExtent() );
QgsDebugMsg( "computedExtent: " + computedExtent.toString() );
QgsDebugMsg( "mCapabilityExtent: " + mShared->mCapabilityExtent.toString() );

// If we didn't get any feature, then return capabilities extent.
if ( computedExtent.isNull() )
return mShared->mCapabilityExtent;

// If the capabilities extent is completely off from the features, then
// use feature extent.
// Case of standplaats layer of http://geodata.nationaalgeoregister.nl/bag/wfs
if ( !computedExtent.intersects( mShared->mCapabilityExtent ) )
return computedExtent;

if ( mShared->downloadFinished() )
{
return computedExtent;
}

computedExtent.combineExtentWith( &mShared->mCapabilityExtent );
return computedExtent;
}

bool QgsWFSProvider::isValid()
@@ -1378,9 +1401,9 @@ bool QgsWFSProvider::getCapabilities()
QgsDebugMsg( "src:" + src.authid() );
QgsDebugMsg( "dst:" + mShared->mSourceCRS.authid() );

mExtent = ct.transformBoundingBox( r, QgsCoordinateTransform::ForwardTransform );
mShared->mCapabilityExtent = ct.transformBoundingBox( r, QgsCoordinateTransform::ForwardTransform );

QgsDebugMsg( "layer ext:" + mExtent.toString() );
QgsDebugMsg( "layer ext:" + mShared->mCapabilityExtent.toString() );
}
if ( mShared->mCaps.featureTypes[i].insertCap )
{
@@ -153,8 +153,6 @@ class QgsWFSProvider : public QgsVectorDataProvider
//! String used to define a subset of the layer
QString mSubsetString;

/** Bounding box for the layer*/
QgsRectangle mExtent;
/** Geometry type of the features in this layer*/
mutable QGis::WkbType mWKBType;
/** Flag if provider is valid*/
@@ -13,6 +13,8 @@
* *
***************************************************************************/

#include <math.h> // M_PI

#include "qgswfsconstants.h"
#include "qgswfsshareddata.h"
#include "qgswfsutils.h"
@@ -34,6 +36,7 @@

#include <QCryptographicHash>


QgsWFSSharedData::QgsWFSSharedData( const QString& uri )
: mURI( uri )
, mSourceCRS( 0 )
@@ -48,6 +51,7 @@ QgsWFSSharedData::QgsWFSSharedData( const QString& uri )
, mFeatureCountExact( false )
, mGetFeatureHitsIssued( false )
, mTotalFeaturesAttemptedToBeCached( 0 )
, mTryFetchingOneFeature( false )
{
// Needed because used by a signal
qRegisterMetaType< QVector<QgsWFSFeatureGmlIdPair> >( "QVector<QgsWFSFeatureGmlIdPair>" );
@@ -514,6 +518,7 @@ int QgsWFSSharedData::registerToCache( QgsWFSFeatureIterator* iterator, QgsRecta
delete mDownloader;
mMutex.lock();
mDownloadFinished = false;
mComputedExtent = QgsRectangle();
mDownloader = new QgsWFSThreadedFeatureDownloader( this );
QEventLoop loop;
connect( mDownloader, SIGNAL( ready() ), &loop, SLOT( quit() ) );
@@ -826,6 +831,7 @@ void QgsWFSSharedData::serializeFeatures( QVector<QgsWFSFeatureGmlIdPair>& featu
existingGmlIds = getExistingCachedGmlIds( featureList );
QVector<QgsWFSFeatureGmlIdPair> updatedFeatureList;

QgsRectangle localComputedExtent( mComputedExtent );
Q_FOREACH ( QgsWFSFeatureGmlIdPair featPair, featureList )
{
const QgsFeature& gmlFeature = featPair.first;
@@ -874,8 +880,13 @@ void QgsWFSSharedData::serializeFeatures( QVector<QgsWFSFeatureGmlIdPair>& featu

cachedFeature.setAttribute( hexwkbGeomIdx, QVariant( QString( array.toHex().data() ) ) );

QgsGeometry* polyBoudingBox = QgsGeometry::fromRect( geometry->boundingBox() );
cachedFeature.setGeometry( polyBoudingBox );
QgsRectangle bBox( geometry->boundingBox() );
if ( localComputedExtent.isNull() )
localComputedExtent = bBox;
else
localComputedExtent.combineExtentWith( &bBox );
QgsGeometry* polyBoundingBox = QgsGeometry::fromRect( bBox );
cachedFeature.setGeometry( polyBoundingBox );
}
else
{
@@ -936,15 +947,30 @@ void QgsWFSSharedData::serializeFeatures( QVector<QgsWFSFeatureGmlIdPair>& featu
if ( !mFeatureCountExact )
mFeatureCount += featureListToCache.size();
mTotalFeaturesAttemptedToBeCached += featureListToCache.size();
if ( !localComputedExtent.isNull() && mComputedExtent.isNull() && !mTryFetchingOneFeature &&
!localComputedExtent.intersects( mCapabilityExtent ) )
{
QgsMessageLog::logMessage( tr( "Layer extent reported by the server is not correct. "
"You may need to zoom again on layer while features are being downloaded" ), tr( "WFS" ) );
}
mComputedExtent = localComputedExtent;
}
}

featureList = updatedFeatureList;

emit extentUpdated();

QgsDebugMsg( QString( "end %1" ).arg( featureList.size() ) );

}

QgsRectangle QgsWFSSharedData::computedExtent()
{
QMutexLocker locker( &mMutex );
return mComputedExtent;
}

void QgsWFSSharedData::pushError( const QString& errorMsg )
{
QgsMessageLog::logMessage( errorMsg, tr( "WFS" ) );
@@ -970,6 +996,36 @@ void QgsWFSSharedData::endOfDownload( bool success, int featureCount,
mDownloadFinished = true;
if ( success && !mRect.isEmpty() )
{
// In the case we requested an extent that includes the extent reported by GetCapabilities response,
// that we have no filter and we got no features, then it is not unlikely that the capabilities
// might be wrong. In which case, query one feature so that we got a beginning of extent from
// which the user will be able to zoom out. This is far from being ideal...
if ( featureCount == 0 && mRect.contains( mCapabilityExtent ) && mWFSFilter.isEmpty() &&
mCaps.supportsHits && !mGeometryAttribute.isEmpty() && !mTryFetchingOneFeature )
{
QgsDebugMsg( "Capability extent is probably wrong. Starting a new request with one feature limit to get at least one feature" );
mTryFetchingOneFeature = true;
QgsWFSSingleFeatureRequest request( this );
mComputedExtent = request.getExtent();
if ( !mComputedExtent.isNull() )
{
// Grow the extent by ~ 50 km (completely arbitrary number if you wonder!)
// so that it is sufficiently zoomed out
if ( mSourceCRS.mapUnits() == QGis::Meters )
mComputedExtent.grow( 50. * 1000. );
else if ( mSourceCRS.mapUnits() == QGis::Degrees )
mComputedExtent.grow( 50. / 110 );
QgsMessageLog::logMessage( tr( "Layer extent reported by the server is not correct. You may need to zoom on layer and then zoom out to see all fetchures" ), tr( "WFS" ) );
}
mMutex.unlock();
if ( !mComputedExtent.isNull() )
{
emit extentUpdated();
}
mMutex.lock();
return;
}

// Arbitrary threshold to avoid the cache of BBOX to grow out of control.
// Note: we could be smarter and keep some BBOXes, but the saturation is
// unlikely to happen in practice, so just clear everything.
@@ -1099,6 +1155,41 @@ int QgsWFSSharedData::getFeatureCount( bool issueRequestIfNeeded )
return mFeatureCount;
}

QgsGmlStreamingParser* QgsWFSSharedData::createParser()
{
QgsGmlStreamingParser::AxisOrientationLogic axisOrientationLogic( QgsGmlStreamingParser::Honour_EPSG_if_urn );
if ( mURI.ignoreAxisOrientation() )
{
axisOrientationLogic = QgsGmlStreamingParser::Ignore_EPSG;
}

if ( mLayerPropertiesList.size() )
{
QList< QgsGmlStreamingParser::LayerProperties > layerPropertiesList;
Q_FOREACH ( QgsOgcUtils::LayerProperties layerProperties, mLayerPropertiesList )
{
QgsGmlStreamingParser::LayerProperties layerPropertiesOut;
layerPropertiesOut.mName = layerProperties.mName;
layerPropertiesOut.mGeometryAttribute = layerProperties.mGeometryAttribute;
layerPropertiesList << layerPropertiesOut;
}

return new QgsGmlStreamingParser( layerPropertiesList,
mFields,
mMapFieldNameToSrcLayerNameFieldName,
axisOrientationLogic,
mURI.invertAxisOrientation() );
}
else
{
return new QgsGmlStreamingParser( mURI.typeName(),
mGeometryAttribute,
mFields,
axisOrientationLogic,
mURI.invertAxisOrientation() );
}
}


// -------------------------

@@ -1165,3 +1256,68 @@ QString QgsWFSFeatureHitsRequest::errorMessageWithReason( const QString& reason
return tr( "Download of feature count failed: %1" ).arg( reason );
}


// -------------------------


QgsWFSSingleFeatureRequest::QgsWFSSingleFeatureRequest( QgsWFSSharedData* shared )
: QgsWFSRequest( shared->mURI.uri() ), mShared( shared )
{
}

QgsWFSSingleFeatureRequest::~QgsWFSSingleFeatureRequest()
{
}

QgsRectangle QgsWFSSingleFeatureRequest::getExtent()
{
QUrl getFeatureUrl( mUri.baseURL() );
getFeatureUrl.addQueryItem( "REQUEST", "GetFeature" );
getFeatureUrl.addQueryItem( "VERSION", mShared->mWFSVersion );
if ( mShared->mWFSVersion .startsWith( "2.0" ) )
getFeatureUrl.addQueryItem( "TYPENAMES", mUri.typeName() );
else
getFeatureUrl.addQueryItem( "TYPENAME", mUri.typeName() );
if ( mShared->mWFSVersion .startsWith( "2.0" ) )
getFeatureUrl.addQueryItem( "COUNT", QString::number( 1 ) );
else
getFeatureUrl.addQueryItem( "MAXFEATURES", QString::number( 1 ) );

if ( !sendGET( getFeatureUrl, true ) )
return -1;

const QByteArray& buffer = response();

QgsDebugMsg( "parsing QgsWFSSingleFeatureRequest: " + buffer );

// parse XML
QgsGmlStreamingParser* parser = mShared->createParser();
QString gmlProcessErrorMsg;
QgsRectangle extent;
if ( parser->processData( buffer, true, gmlProcessErrorMsg ) )
{
QVector<QgsGmlStreamingParser::QgsGmlFeaturePtrGmlIdPair> featurePtrList =
parser->getAndStealReadyFeatures();
QVector<QgsWFSFeatureGmlIdPair> featureList;
for ( int i = 0;i < featurePtrList.size();i++ )
{
QgsGmlStreamingParser::QgsGmlFeaturePtrGmlIdPair& featPair = featurePtrList[i];
QgsFeature f( *( featPair.first ) );
const QgsGeometry* geometry = f.constGeometry();
if ( geometry )
{
extent = geometry->boundingBox();
}
delete featPair.first;
}
}
delete parser;
return extent;
}

QString QgsWFSSingleFeatureRequest::errorMessageWithReason( const QString& reason )
{
return tr( "Download of feature failed: %1" ).arg( reason );
}


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