Refactor to move JSON exporter to its own class

qgis · May 9, 2016 · c3f6c39 · c3f6c39
1 parent 935f4ad
commit c3f6c39
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Showing 5 changed files with 236 additions and 57 deletions.
diff --git a/python/core/qgsjsonutils.sip b/python/core/qgsjsonutils.sip
@@ -1,3 +1,81 @@
+/** \ingroup core
+ * \class QgsJSONExporter
+ * \brief Handles exporting QgsFeature features to GeoJSON features.
+ * \note Added in version 2.16
+ */
+
+class QgsJSONExporter
+{
+%TypeHeaderCode
+#include <qgsjsonutils.h>
+%End
+  public:
+
+    /** Constructor for QgsJSONExporter.
+     * @param precision maximum number of decimal places to use for geometry coordinates
+     * @param includeGeometry set to false to avoid including the geometry representation in the JSON output
+     * @param includeAttributes set to false to avoid including any attribute values in the JSON output
+     */
+    QgsJSONExporter( int precision = 17, bool includeGeometry = true, bool includeAttributes = true );
+
+    /** Sets the maximum number of decimal places to use in geometry coordinates.
+     * @param precision number of decimal places
+     * @see precision()
+     */
+    void setPrecision( int precision );
+
+    /** Returns the maximum number of decimal places to use in geometry coordinates.
+     * @see setPrecision()
+     */
+    int precision() const;
+
+    /** Sets whether to include geometry in the JSON exports.
+     * @param includeGeometry set to false to prevent geometry inclusion
+     * @see includeGeometry()
+     */
+    void setIncludeGeometry( bool includeGeometry );
+
+    /** Returns whether geometry will be included in the JSON exports.
+     * @see setIncludeGeometry()
+     */
+    bool includeGeometry() const;
+
+    /** Sets whether to include attributes in the JSON exports.
+     * @param includeAttributes set to false to prevent attribute inclusion
+     * @see includeAttributes()
+     */
+    void setIncludeAttributes( bool includeAttributes );
+
+    /** Returns whether attributes will be included in the JSON exports.
+     * @see setIncludeAttributes()
+     */
+    bool includeAttributes() const;
+
+    /** Sets the list of attributes to include in the JSON exports.
+     * @param attributes list of attribute indexes, or an empty list to include all
+     * attributes
+     * @see attributes()
+     */
+    void setAttributes( const QgsAttributeList& attributes );
+
+    /** Returns the list of attributes which will be included in the JSON exports, or
+     * an empty list if all attributes will be included.
+     * @see setAttributes()
+     */
+    QgsAttributeList attributes() const;
+
+    /** Returns a GeoJSON string representation of a feature.
+     * @param feature feature to convert
+     * @param id optional ID to use as GeoJSON feature's ID instead of input feature's ID. If omitted, feature's
+     * ID is used.
+     * @returns GeoJSON string
+     */
+    QString exportFeature( const QgsFeature& feature,
+                           const QVariant& id = QVariant() ) const;
+
+};
+
+
 /** \ingroup core
  * \class QgsJSONUtils
  * \brief Helper utilities for working with JSON and GeoJSON conversions.
@@ -31,24 +109,6 @@ class QgsJSONUtils
      */
     static QgsFields stringToFields( const QString& string, QTextCodec* encoding );
 
-    /** Returns a GeoJSON string representation of a feature.
-     * @param feature feature to convert
-     * @param precision maximum number of decimal places to use for geometry coordinates
-     * @param attrIndexes list of attribute indexes to include in GeoJSON, or an empty list to include
-     * all attributes
-     * @param includeGeom set to false to avoid including the geometry representation in the JSON output
-     * @param includeAttributes set to false to avoid including any attribute values in the JSON output
-     * @param id optional ID to use as GeoJSON feature's ID instead of input feature's ID. If omitted, feature's
-     * ID is used.
-     * @returns GeoJSON string
-     */
-    static QString featureToGeoJSON( const QgsFeature& feature,
-                                     int precision = 17,
-                                     const QgsAttributeList& attrIndexes = QgsAttributeList(),
-                                     bool includeGeom = true,
-                                     bool includeAttributes = true,
-                                     const QVariant& id = QVariant() );
-
     /** Encodes a value to a JSON string representation, adding appropriate quotations and escaping
      * where required.
      * @param value value to encode

diff --git a/src/core/qgsjsonutils.cpp b/src/core/qgsjsonutils.cpp
@@ -17,54 +17,48 @@
 #include "qgsogrutils.h"
 #include "qgsgeometry.h"
 
-QgsFeatureList QgsJSONUtils::stringToFeatureList( const QString &string, const QgsFields &fields, QTextCodec *encoding )
-{
-  return QgsOgrUtils::stringToFeatureList( string, fields, encoding );
-}
 
-QgsFields QgsJSONUtils::stringToFields( const QString &string, QTextCodec *encoding )
+QgsJSONExporter::QgsJSONExporter( int precision, bool includeGeometry, bool includeAttributes )
+    : mPrecision( precision )
+    , mIncludeGeometry( includeGeometry )
+    , mIncludeAttributes( includeAttributes )
 {
-  return QgsOgrUtils::stringToFields( string, encoding );
+
 }
 
-QString QgsJSONUtils::featureToGeoJSON( const QgsFeature& feature,
-                                        int precision,
-                                        const QgsAttributeList& attrIndexes,
-                                        bool includeGeom,
-                                        bool includeAttributes,
-                                        const QVariant& id )
+QString QgsJSONExporter::exportFeature( const QgsFeature& feature, const QVariant& id ) const
 {
   QString s = "{\n   \"type\":\"Feature\",\n";
 
   // ID
-  s += QString( "   \"id\":%1" ).arg( !id.isValid() ? QString::number( feature.id() ) : encodeValue( id ) );
+  s += QString( "   \"id\":%1" ).arg( !id.isValid() ? QString::number( feature.id() ) : QgsJSONUtils::encodeValue( id ) );
 
-  if ( includeAttributes || includeGeom )
+  if ( mIncludeAttributes || mIncludeGeometry )
     s += ",\n";
   else
     s += '\n';
 
   const QgsGeometry* geom = feature.constGeometry();
-  if ( geom && !geom->isEmpty() && includeGeom )
+  if ( geom && !geom->isEmpty() && mIncludeGeometry )
   {
     QgsRectangle box = geom->boundingBox();
 
     if ( QgsWKBTypes::flatType( geom->geometry()->wkbType() ) != QgsWKBTypes::Point )
     {
-      s += QString( "   \"bbox\":[%1, %2, %3, %4],\n" ).arg( qgsDoubleToString( box.xMinimum(), precision ),
-           qgsDoubleToString( box.yMinimum(), precision ),
-           qgsDoubleToString( box.xMaximum(), precision ),
-           qgsDoubleToString( box.yMaximum(), precision ) );
+      s += QString( "   \"bbox\":[%1, %2, %3, %4],\n" ).arg( qgsDoubleToString( box.xMinimum(), mPrecision ),
+           qgsDoubleToString( box.yMinimum(), mPrecision ),
+           qgsDoubleToString( box.xMaximum(), mPrecision ),
+           qgsDoubleToString( box.yMaximum(), mPrecision ) );
     }
     s += "   \"geometry\":\n   ";
-    s += geom->exportToGeoJSON( precision );
-    if ( includeAttributes )
+    s += geom->exportToGeoJSON( mPrecision );
+    if ( mIncludeAttributes )
       s += ",\n";
     else
       s += '\n';
   }
 
-  if ( includeAttributes )
+  if ( mIncludeAttributes )
   {
     //read all attribute values from the feature
     s += "   \"properties\":{\n";
@@ -74,14 +68,14 @@ QString QgsJSONUtils::featureToGeoJSON( const QgsFeature& feature,
 
     for ( int i = 0; i < fields->count(); ++i )
     {
-      if ( !attrIndexes.isEmpty() && !attrIndexes.contains( i ) )
+      if ( !mAttributeIndexes.isEmpty() && !mAttributeIndexes.contains( i ) )
         continue;
 
       if ( attributeCounter > 0 )
         s += ",\n";
       QVariant val =  feature.attributes().at( i );
 
-      s += QString( "      \"%1\":%2" ).arg( fields->at( i ).name(), encodeValue( val ) );
+      s += QString( "      \"%1\":%2" ).arg( fields->at( i ).name(), QgsJSONUtils::encodeValue( val ) );
 
       ++attributeCounter;
     }
@@ -94,6 +88,21 @@ QString QgsJSONUtils::featureToGeoJSON( const QgsFeature& feature,
   return s;
 }
 
+
+//
+// QgsJSONUtils
+//
+
+QgsFeatureList QgsJSONUtils::stringToFeatureList( const QString &string, const QgsFields &fields, QTextCodec *encoding )
+{
+  return QgsOgrUtils::stringToFeatureList( string, fields, encoding );
+}
+
+QgsFields QgsJSONUtils::stringToFields( const QString &string, QTextCodec *encoding )
+{
+  return QgsOgrUtils::stringToFields( string, encoding );
+}
+
 QString QgsJSONUtils::encodeValue( const QVariant &value )
 {
   if ( value.isNull() )

diff --git a/src/core/qgsjsonutils.h b/src/core/qgsjsonutils.h
@@ -20,6 +20,94 @@
 
 class QTextCodec;
 
+/** \ingroup core
+ * \class QgsJSONExporter
+ * \brief Handles exporting QgsFeature features to GeoJSON features.
+ * \note Added in version 2.16
+ */
+
+class CORE_EXPORT QgsJSONExporter
+{
+  public:
+
+    /** Constructor for QgsJSONExporter.
+     * @param precision maximum number of decimal places to use for geometry coordinates
+     * @param includeGeometry set to false to avoid including the geometry representation in the JSON output
+     * @param includeAttributes set to false to avoid including any attribute values in the JSON output
+     */
+    QgsJSONExporter( int precision = 17, bool includeGeometry = true, bool includeAttributes = true );
+
+    /** Sets the maximum number of decimal places to use in geometry coordinates.
+     * @param precision number of decimal places
+     * @see precision()
+     */
+    void setPrecision( int precision ) { mPrecision = precision; }
+
+    /** Returns the maximum number of decimal places to use in geometry coordinates.
+     * @see setPrecision()
+     */
+    int precision() const { return mPrecision; }
+
+    /** Sets whether to include geometry in the JSON exports.
+     * @param includeGeometry set to false to prevent geometry inclusion
+     * @see includeGeometry()
+     */
+    void setIncludeGeometry( bool includeGeometry ) { mIncludeGeometry = includeGeometry; }
+
+    /** Returns whether geometry will be included in the JSON exports.
+     * @see setIncludeGeometry()
+     */
+    bool includeGeometry() const { return mIncludeGeometry; }
+
+    /** Sets whether to include attributes in the JSON exports.
+     * @param includeAttributes set to false to prevent attribute inclusion
+     * @see includeAttributes()
+     */
+    void setIncludeAttributes( bool includeAttributes ) { mIncludeAttributes = includeAttributes; }
+
+    /** Returns whether attributes will be included in the JSON exports.
+     * @see setIncludeAttributes()
+     */
+    bool includeAttributes() const { return mIncludeAttributes; }
+
+    /** Sets the list of attributes to include in the JSON exports.
+     * @param attributes list of attribute indexes, or an empty list to include all
+     * attributes
+     * @see attributes()
+     */
+    void setAttributes( const QgsAttributeList& attributes ) { mAttributeIndexes = attributes; }
+
+    /** Returns the list of attributes which will be included in the JSON exports, or
+     * an empty list if all attributes will be included.
+     * @see setAttributes()
+     */
+    QgsAttributeList attributes() const { return mAttributeIndexes; }
+
+    /** Returns a GeoJSON string representation of a feature.
+     * @param feature feature to convert
+     * @param id optional ID to use as GeoJSON feature's ID instead of input feature's ID. If omitted, feature's
+     * ID is used.
+     * @returns GeoJSON string
+     */
+    QString exportFeature( const QgsFeature& feature,
+                           const QVariant& id = QVariant() ) const;
+
+  private:
+
+    //! Maximum number of decimal places for geometry coordinates
+    int mPrecision;
+
+    //! List of attribute indexes to include in export, or empty list to include all attributes
+    QgsAttributeList mAttributeIndexes;
+
+    //! Whether to include geometry in JSON export
+    bool mIncludeGeometry;
+
+    //! Whether to include attributes in JSON export
+    bool mIncludeAttributes;
+
+};
+
 /** \ingroup core
  * \class QgsJSONUtils
  * \brief Helper utilities for working with JSON and GeoJSON conversions.

diff --git a/src/server/qgswfsserver.cpp b/src/server/qgswfsserver.cpp
@@ -1868,13 +1868,16 @@ QString QgsWFSServer::createFeatureGeoJSON( QgsFeature* feat, int prec, QgsCoord
 {
   QString id = QString( "%1.%2" ).arg( mTypeName, FID_TO_STRING( feat->id() ) );
 
+  QgsJSONExporter exporter;
+  exporter.setPrecision( prec );
+
   //copy feature so we can modify its geometry as required
   QgsFeature f( *feat );
   const QgsGeometry* geom = feat->constGeometry();
-  bool withGeom = false;
+  exporter.setIncludeGeometry( false );
   if ( geom && mWithGeom && mGeometryName != "NONE" )
   {
-    withGeom = true;
+    exporter.setIncludeGeometry( true );
     if ( mGeometryName == "EXTENT" )
     {
       QgsRectangle box = geom->boundingBox();
@@ -1907,9 +1910,10 @@ QString QgsWFSServer::createFeatureGeoJSON( QgsFeature* feat, int prec, QgsCoord
     attrsToExport << idx;
   }
 
-  bool withAttributes = !attrsToExport.isEmpty();
+  exporter.setIncludeAttributes( !attrsToExport.isEmpty() );
+  exporter.setAttributes( attrsToExport );
 
-  return QgsJSONUtils::featureToGeoJSON( f, prec, attrsToExport, withGeom, withAttributes, id );
+  return exporter.exportFeature( f, id );
 }
 
 QDomElement QgsWFSServer::createFeatureGML2( QgsFeature* feat, QDomDocument& doc, int prec, QgsCoordinateReferenceSystem& crs, const QgsAttributeList& attrIndexes, const QSet<QString>& excludedAttributes ) /*const*/