Add regexp_match function, improve help for regexp_replace function

qgis · Apr 28, 2013 · 533030f · 533030f
1 parent 6e5221c
commit 533030f
Show file tree

Hide file tree

Showing 4 changed files with 39 additions and 5 deletions.
diff --git a/resources/function_help/regexp_match-en_US b/resources/function_help/regexp_match-en_US
@@ -0,0 +1,14 @@
+<h3>regexp_match() function</h3>
+Returns true if any part of a string matches the supplied regular expression.
+
+<p><h4>Syntax</h4>
+     regexp_match(<i>string,regex</i>)</p>
+
+<p><h4>Arguments</h4>
+<!-- List args for functions here-->
+<i>  string</i> &rarr; is string.  The string to test against the regular expression.<br>
+<i>  regex</i> &rarr; is string.  The regular expression to test against. Backslash characters must be double escaped (eg "\\s" to match a white space character).<br>
+
+<p><h4>Example</h4>
+<!-- Show example of function.-->
+     regexp_match('QGIS ROCKS','\\sROCKS') &rarr; 1</p>
diff --git a/resources/function_help/regexp_replace-en_US b/resources/function_help/regexp_replace-en_US
@@ -2,14 +2,14 @@
 Returns a string with the supplied regular expression replaced.
 
 <p><h4>Syntax</h4>
-     replace(<i>string,before,after</i>)</p>
+     regexp_replace(<i>string,regex,after</i>)</p>
 
 <p><h4>Arguments</h4>
 <!-- List args for functions here-->
 <i>  string</i> &rarr; is string.  The start string.<br>
-<i>  before</i> &rarr; is string.  The string to replace.<br>
-<i>  after</i> &rarr; is string.  The string that will replace <i>before</i><br></p>
+<i>  regex</i> &rarr; is string.  The regular expression to replace. Backslash characters must be double escaped (eg "\\s" to match a white space character).<br>
+<i>  after</i> &rarr; is string.  The string that will replace any matching occurences of the supplied regular expression. Captured groups can be inserted into the replacement string using \\1, \\2, etc. <br></p>
 
 <p><h4>Example</h4>
 <!-- Show example of function.-->
-     replace('QGIS SHOULD ROCK','SHOULD','DOES') &rarr; 'QGIS DOES ROCK'</p>
+     regexp_replace('QGIS SHOULD ROCK','\\sSHOULD\\s',' DOES ') &rarr; 'QGIS DOES ROCK'</p>
diff --git a/src/core/qgsexpression.cpp b/src/core/qgsexpression.cpp
@@ -485,6 +485,21 @@ static QVariant fcnRegexpReplace( const QVariantList& values, QgsFeature* , QgsE
   }
   return QVariant( str.replace( re, after ) );
 }
+
+static QVariant fcnRegexpMatch( const QVariantList& values, QgsFeature* , QgsExpression* parent )
+{
+  QString str = getStringValue( values.at( 0 ), parent );
+  QString regexp = getStringValue( values.at( 1 ), parent );
+
+  QRegExp re( regexp );
+  if ( !re.isValid() )
+  {
+    parent->setEvalErrorString( QObject::tr( "Invalid regular expression '%1': %2" ).arg( regexp ).arg( re.errorString() ) );
+    return QVariant();
+  }
+  return QVariant( str.contains( re ) ? 1 : 0 );
+}
+
 static QVariant fcnSubstr( const QVariantList& values, QgsFeature* , QgsExpression* parent )
 {
   QString str = getStringValue( values.at( 0 ), parent );
@@ -1194,7 +1209,7 @@ const QStringList &QgsExpression::BuiltinFunctions()
     << "exp" << "ln" << "log10" << "log"
     << "round" << "toint" << "toreal" << "tostring"
     << "todatetime" << "todate" << "totime" << "tointerval"
-    << "coalesce" << "$now" << "age" << "year"
+    << "coalesce" << "regexp_match" << "$now" << "age" << "year"
     << "month" << "week" << "day" << "hour"
     << "minute" << "second" << "lower" << "upper"
     << "title" << "length" << "replace" << "regexp_replace"
@@ -1240,6 +1255,7 @@ const QList<QgsExpression::Function*> &QgsExpression::Functions()
     << new StaticFunction( "totime", 1, fcnToTime, QObject::tr( "Conversions" ) )
     << new StaticFunction( "tointerval", 1, fcnToInterval, QObject::tr( "Conversions" ) )
     << new StaticFunction( "coalesce", -1, fcnCoalesce, QObject::tr( "Conditionals" ) )
+    << new StaticFunction( "regexp_match", 2, fcnRegexpMatch, QObject::tr( "Conditionals" ) )
     << new StaticFunction( "$now", 0, fcnNow, QObject::tr( "Date and Time" ) )
     << new StaticFunction( "age", 2, fcnAge, QObject::tr( "Date and Time" ) )
     << new StaticFunction( "year", 1, fcnYear, QObject::tr( "Date and Time" ) )

diff --git a/tests/src/core/testqgsexpression.cpp b/tests/src/core/testqgsexpression.cpp
@@ -302,6 +302,10 @@ class TestQgsExpression: public QObject
       QTest::newRow( "coalesce null" ) << "coalesce(NULL)" << false << QVariant( );
       QTest::newRow( "coalesce mid-null" ) << "coalesce(1, NULL, 3)" << false << QVariant( 1 );
       QTest::newRow( "coalesce exp" ) << "coalesce(NULL, 1+1)" << false << QVariant( 2 );
+      QTest::newRow( "regexp match" ) << "regexp_match('abc','.b.')" << false << QVariant( 1 );
+      QTest::newRow( "regexp match invalid" ) << "regexp_match('abc DEF','[[[')" << true << QVariant();
+      QTest::newRow( "regexp match escaped" ) << "regexp_match('abc DEF','\\\\s[A-Z]+')" << false << QVariant( 1 );
+      QTest::newRow( "regexp match false" ) << "regexp_match('abc DEF','\\\\s[a-z]+')" << false << QVariant( 0 );
 
       // Datetime functions
       QTest::newRow( "to date" ) << "todate('2012-06-28')" << false << QVariant( QDate( 2012, 6, 28 ) );