From 387057a1b885f499ff2c5ce2ac2f8d79202da14f Mon Sep 17 00:00:00 2001
From: Etienne Trimaille <gustrimaille@yahoo.fr>
Date: Thu, 31 Aug 2017 16:07:02 +0200
Subject: [PATCH] add CRS description in the layer_property expression

---
 resources/function_help/json/layer_property   | 2 +-
 src/core/expression/qgsexpressionfunction.cpp | 2 ++
 tests/src/core/testqgsexpression.cpp          | 2 ++
 3 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/resources/function_help/json/layer_property b/resources/function_help/json/layer_property
index 470c33db79b..f6c33d482fe 100644
--- a/resources/function_help/json/layer_property
+++ b/resources/function_help/json/layer_property
@@ -4,7 +4,7 @@
   "description": "Returns a matching layer property or metadata value.",
   "arguments": [
 	{"arg":"layer", "description":"a string, representing either a layer name or layer ID"},
-	{"arg":"property", "description":"a string corresponding to the property to return. Valid options are:<br /><ul><li>name: layer name</li><li>id: layer ID</li><li>title: metadata title string</li><li>abstract: metadata abstract string</li><li>keywords: metadata keywords</li><li>data_url: metadata URL</li><li>attribution: metadata attribution string</li><li>attribution_url: metadata attribution URL</li><li>source: layer source</li><li>min_scale: minimum display scale for layer</li><li>max_scale: maximum display scale for layer</li><li>crs: layer CRS</li><li>crs_definition: layer CRS full definition</li> <li>extent: layer extent (as a geometry object)</li><li>type: layer type, e.g., Vector or Raster</li><li>storage_type: storage format (vector layers only)</li><li>geometry_type: geometry type, e.g., Point (vector layers only)</li><li>feature_count: approximate feature count for layer (vector layers only)</li></ul>"}
+        {"arg":"property", "description":"a string corresponding to the property to return. Valid options are:<br /><ul><li>name: layer name</li><li>id: layer ID</li><li>title: metadata title string</li><li>abstract: metadata abstract string</li><li>keywords: metadata keywords</li><li>data_url: metadata URL</li><li>attribution: metadata attribution string</li><li>attribution_url: metadata attribution URL</li><li>source: layer source</li><li>min_scale: minimum display scale for layer</li><li>max_scale: maximum display scale for layer</li><li>crs: layer CRS</li><li>crs_definition: layer CRS full definition</li><li>crs_description: layer CRS description</li><li>extent: layer extent (as a geometry object)</li><li>type: layer type, e.g., Vector or Raster</li><li>storage_type: storage format (vector layers only)</li><li>geometry_type: geometry type, e.g., Point (vector layers only)</li><li>feature_count: approximate feature count for layer (vector layers only)</li></ul>"}
   ],
   "examples": [
 	{ "expression":"layer_property('streets','title')", "returns":"'Basemap Streets'"},
diff --git a/src/core/expression/qgsexpressionfunction.cpp b/src/core/expression/qgsexpressionfunction.cpp
index 97ba905bd45..769e6f9883c 100644
--- a/src/core/expression/qgsexpressionfunction.cpp
+++ b/src/core/expression/qgsexpressionfunction.cpp
@@ -3515,6 +3515,8 @@ static QVariant fcnGetLayerProperty( const QVariantList &values, const QgsExpres
     return layer->crs().authid();
   else if ( QString::compare( layerProperty, QStringLiteral( "crs_definition" ), Qt::CaseInsensitive ) == 0 )
     return layer->crs().toProj4();
+  else if ( QString::compare( layerProperty, QStringLiteral( "crs_description" ), Qt::CaseInsensitive ) == 0 )
+    return layer->crs().description();
   else if ( QString::compare( layerProperty, QStringLiteral( "extent" ), Qt::CaseInsensitive ) == 0 )
   {
     QgsGeometry extentGeom = QgsGeometry::fromRect( layer->extent() );
diff --git a/tests/src/core/testqgsexpression.cpp b/tests/src/core/testqgsexpression.cpp
index 921b4574035..dcf804be299 100644
--- a/tests/src/core/testqgsexpression.cpp
+++ b/tests/src/core/testqgsexpression.cpp
@@ -1149,6 +1149,8 @@ class TestQgsExpression: public QObject
       QTest::newRow( "layer_property min_scale" ) << QStringLiteral( "layer_property('%1','min_scale')" ).arg( mPointsLayer->name() ) << false << QVariant( mPointsLayer->minimumScale() );
       QTest::newRow( "layer_property max_scale" ) << QStringLiteral( "layer_property('%1','max_scale')" ).arg( mPointsLayer->name() ) << false << QVariant( mPointsLayer->maximumScale() );
       QTest::newRow( "layer_property crs" ) << QStringLiteral( "layer_property('%1','crs')" ).arg( mPointsLayer->name() ) << false << QVariant( "EPSG:4326" );
+      QTest::newRow( "layer_property crs_description" ) << QStringLiteral( "layer_property('%1','crs_description')" ).arg( mPointsLayer->name() ) << false << QVariant( "WGS 84" );
+      QTest::newRow( "layer_property crs_definition" ) << QStringLiteral( "layer_property('%1','crs_definition')" ).arg( mPointsLayer->name() ) << false << QVariant( "+proj=longlat +datum=WGS84 +no_defs" );
       QTest::newRow( "layer_property extent" ) << QStringLiteral( "geom_to_wkt(layer_property('%1','extent'))" ).arg( mPointsLayer->name() ) << false << QVariant( "Polygon ((-118.88888889 22.80020704, -83.33333333 22.80020704, -83.33333333 46.87198068, -118.88888889 46.87198068, -118.88888889 22.80020704))" );
       QTest::newRow( "layer_property type" ) << QStringLiteral( "layer_property('%1','type')" ).arg( mPointsLayer->name() ) << false << QVariant( "Vector" );
       QTest::newRow( "layer_property storage_type" ) << QStringLiteral( "layer_property('%1','storage_type')" ).arg( mPointsLayer->name() ) << false << QVariant( "ESRI Shapefile" );