Merge pull request #4284 from arnaud-morvan/expression_compare_arrays

Add arrays comparison in QgsExpression
qgis · Apr 23, 2017 · f7b7254 · f7b7254
2 parents 268acab + 8385cd9
commit f7b7254
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diff --git a/src/core/qgsexpression.cpp b/src/core/qgsexpression.cpp
@@ -176,6 +176,11 @@ inline bool isNull( const QVariant &v )
   return v.isNull();
 }
 
+inline bool isList( const QVariant &v )
+{
+  return v.type() == QVariant::List;
+}
+
 ///////////////////////////////////////////////
 // evaluation error macros
 
@@ -4257,6 +4262,16 @@ QString QgsExpression::quotedValue( const QVariant &value, QVariant::Type type )
     case QVariant::Bool:
       return value.toBool() ? "TRUE" : "FALSE";
 
+    case QVariant::List:
+    {
+      QStringList quotedValues;
+      Q_FOREACH ( const QVariant &v, value.toList() )
+      {
+        quotedValues += quotedValue( v );
+      }
+      return QStringLiteral( "array( %1 )" ).arg( quotedValues.join( ", " ) );
+    }
+
     default:
     case QVariant::String:
       return quotedString( value.toString() );
@@ -4834,6 +4849,75 @@ QVariant QgsExpression::NodeBinaryOperator::eval( QgsExpression *parent, const Q
       {
         return TVL_Unknown;
       }
+      else if ( isList( vL ) || isList( vR ) )
+      {
+        // verify that we have two lists
+        if ( !isList( vL ) || !isList( vR ) )
+          return TVL_Unknown;
+
+        // and search for not equal respective items
+        QVariantList lL = vL.toList();
+        QVariantList lR = vR.toList();
+        for ( int i = 0; i < lL.length() && i < lR.length(); i++ )
+        {
+          if ( isNull( lL.at( i ) ) && isNull( lR.at( i ) ) )
+            continue;  // same behavior as PostgreSQL
+
+          if ( isNull( lL.at( i ) ) || isNull( lR.at( i ) ) )
+          {
+            switch ( mOp )
+            {
+              case boEQ:
+                return false;
+              case boNE:
+                return true;
+              case boLT:
+              case boLE:
+                return isNull( lR.at( i ) );
+              case boGT:
+              case boGE:
+                return isNull( lL.at( i ) );
+              default:
+                Q_ASSERT( false );
+                return TVL_Unknown;
+            }
+          }
+
+          QgsExpression::NodeLiteral nL( lL.at( i ) );
+          QgsExpression::NodeLiteral nR( lR.at( i ) );
+          QgsExpression::NodeBinaryOperator eqNode( boEQ, nL.clone(), nR.clone() );
+          QVariant eq = eqNode.eval( parent, context );
+          ENSURE_NO_EVAL_ERROR;
+          if ( eq == TVL_False )
+          {
+            // return the two items comparison
+            QgsExpression::NodeBinaryOperator node( mOp, nL.clone(), nR.clone() );
+            QVariant v = node.eval( parent, context );
+            ENSURE_NO_EVAL_ERROR;
+            return v;
+          }
+        }
+
+        // default to length comparison
+        switch ( mOp )
+        {
+          case boEQ:
+            return lL.length() == lR.length();
+          case boNE:
+            return lL.length() != lR.length();
+          case boLT:
+            return lL.length() < lR.length();
+          case boGT:
+            return lL.length() > lR.length();
+          case boLE:
+            return lL.length() <= lR.length();
+          case boGE:
+            return lL.length() >= lR.length();
+          default:
+            Q_ASSERT( false );
+            return TVL_Unknown;
+        }
+      }
       else if ( isDoubleSafe( vL ) && isDoubleSafe( vR ) &&
                 ( vL.type() != QVariant::String || vR.type() != QVariant::String ) )
       {

diff --git a/tests/src/core/testqgsexpression.cpp b/tests/src/core/testqgsexpression.cpp
@@ -2447,6 +2447,48 @@ class TestQgsExpression: public QObject
       QCOMPARE( badArray.evalErrorString(), QString( "Cannot convert 'not an array' to array" ) );
     }
 
+    void compare_arrays()
+    {
+      QCOMPARE( QgsExpression( "array() = array()" ).evaluate(), QVariant( true ) );
+      QCOMPARE( QgsExpression( "array(NULL) = array(NULL)" ).evaluate(), QVariant( true ) );
+      QCOMPARE( QgsExpression( "array() = array(NULL)" ).evaluate(), QVariant( false ) );
+      QCOMPARE( QgsExpression( "array(1, NULL) = array(NULL, 1)" ).evaluate(), QVariant( false ) );
+
+      QCOMPARE( QgsExpression( "array('hello') = array('hello')" ).evaluate(), QVariant( true ) );
+      QCOMPARE( QgsExpression( "array('hello') = array('hello2')" ).evaluate(), QVariant( false ) );
+      QCOMPARE( QgsExpression( "array('h', 'e', 'l', 'l', 'o') = array('h', 'e', 'l', 'l', 'o')" ).evaluate(), QVariant( true ) );
+      QCOMPARE( QgsExpression( "array('h', 'e', 'l', 'l', 'o') = array('h', 'e', 'l', 'l')" ).evaluate(), QVariant( false ) );
+
+      QCOMPARE( QgsExpression( "array('1') = array(1)" ).evaluate(), QVariant( true ) );
+      QCOMPARE( QgsExpression( "array('1.2') = array(1.2)" ).evaluate(), QVariant( true ) );
+
+      QCOMPARE( QgsExpression( "array() != array()" ).evaluate(), QVariant( false ) );
+      QCOMPARE( QgsExpression( "array(NULL) != array(NULL)" ).evaluate(), QVariant( false ) );
+      QCOMPARE( QgsExpression( "array() != array(NULL)" ).evaluate(), QVariant( true ) );
+      QCOMPARE( QgsExpression( "array('hello') != array('hello')" ).evaluate(), QVariant( false ) );
+      QCOMPARE( QgsExpression( "array('hello') != array('hello2')" ).evaluate(), QVariant( true ) );
+
+      QCOMPARE( QgsExpression( "array() < array(1)" ).evaluate(), QVariant( true ) );
+      QCOMPARE( QgsExpression( "array(1) < array(NULL)" ).evaluate(), QVariant( true ) );
+      QCOMPARE( QgsExpression( "array(1) < array(1)" ).evaluate(), QVariant( false ) );
+      QCOMPARE( QgsExpression( "array(1) < array(2)" ).evaluate(), QVariant( true ) );
+      QCOMPARE( QgsExpression( "array(2) < array(1)" ).evaluate(), QVariant( false ) );
+      QCOMPARE( QgsExpression( "array(1) < array(1, 2)" ).evaluate(), QVariant( true ) );
+      QCOMPARE( QgsExpression( "array(1, 2) < array(1)" ).evaluate(), QVariant( false ) );
+      QCOMPARE( QgsExpression( "array('h', 'e', 'l', 'l', 'o') < array('h', 'e', 'l', 'l')" ).evaluate(), QVariant( false ) );
+      QCOMPARE( QgsExpression( "array('h', 'e', 'l', 'l', 'o') > array('h', 'e', 'l', 'l')" ).evaluate(), QVariant( true ) );
+
+      QCOMPARE( QgsExpression( "array() <= array(1)" ).evaluate(), QVariant( true ) );
+      QCOMPARE( QgsExpression( "array(1) <= array(NULL)" ).evaluate(), QVariant( true ) );
+      QCOMPARE( QgsExpression( "array(1) <= array(1)" ).evaluate(), QVariant( true ) );
+      QCOMPARE( QgsExpression( "array(1) <= array(2)" ).evaluate(), QVariant( true ) );
+      QCOMPARE( QgsExpression( "array(2) <= array(1)" ).evaluate(), QVariant( false ) );
+      QCOMPARE( QgsExpression( "array(1) <= array(1, 2)" ).evaluate(), QVariant( true ) );
+      QCOMPARE( QgsExpression( "array(1, 2) <= array(1)" ).evaluate(), QVariant( false ) );
+      QCOMPARE( QgsExpression( "array('h', 'e', 'l', 'l', 'o') <= array('h', 'e', 'l', 'l')" ).evaluate(), QVariant( false ) );
+      QCOMPARE( QgsExpression( "array('h', 'e', 'l', 'l', 'o') >= array('h', 'e', 'l', 'l')" ).evaluate(), QVariant( true ) );
+    }
+
     void eval_map()
     {
       QgsFeature f( 100 );
@@ -2543,6 +2585,8 @@ class TestQgsExpression: public QObject
       QCOMPARE( QgsExpression::quotedValue( QVariant( true ), QVariant::String ), QString( "'true'" ) );
       QCOMPARE( QgsExpression::quotedValue( QVariant() ), QString( "NULL" ) );
       QCOMPARE( QgsExpression::quotedValue( QVariant(), QVariant::String ), QString( "NULL" ) );
+      QVariantList array = QVariantList() << QVariant( 1 ) << QVariant( "a" ) << QVariant();
+      QCOMPARE( QgsExpression::quotedValue( array ), QString( "array( 1, 'a', NULL )" ) );
     }
 
     void reentrant()