#61 add input location support when building XPP3 DOM

pom.xml

@@ -26,7 +26,7 @@ limitations under the License.
   </parent>
 
   <artifactId>plexus-utils</artifactId>
-  <version>3.1.2-SNAPSHOT</version>
+  <version>3.2.0-SNAPSHOT</version>
 
   <name>Plexus Common Utilities</name>
   <description>A collection of various utility classes to ease working with strings, files, command lines, XML and

src/main/java/org/codehaus/plexus/util/xml/Xpp3Dom.java

@@ -48,6 +48,11 @@ public class Xpp3Dom
 
     protected Xpp3Dom parent;
 
+    /**
+     * @since 3.2.0
+     */
+    protected Object inputLocation;
+
     private static final String[] EMPTY_STRING_ARRAY = new String[0];
 
     private static final Xpp3Dom[] EMPTY_DOM_ARRAY = new Xpp3Dom[0];
@@ -278,6 +283,26 @@ public void setParent( Xpp3Dom parent )
         this.parent = parent;
     }
 
+    // ----------------------------------------------------------------------
+    // Input location handling
+    // ----------------------------------------------------------------------
+
+    /**
+     * @since 3.2.0
+     */
+    public Object getInputLocation()
+    {
+        return inputLocation;
+    }
+
+    /**
+     * @since 3.2.0
+     */
+    public void setInputLocation( Object inputLocation )
+    {
+        this.inputLocation = inputLocation;
+    }
+
     // ----------------------------------------------------------------------
     // Helpers
     // ----------------------------------------------------------------------

src/main/java/org/codehaus/plexus/util/xml/Xpp3DomBuilder.java

@@ -37,7 +37,16 @@ public class Xpp3DomBuilder
     public static Xpp3Dom build( Reader reader )
         throws XmlPullParserException, IOException
     {
-        return build( reader, DEFAULT_TRIM );
+        return build( reader, null );
+    }
+
+    /**
+     * @since 3.2.0
+     */
+    public static Xpp3Dom build( Reader reader, InputLocationBuilder locationBuilder )
+        throws XmlPullParserException, IOException
+    {
+        return build( reader, DEFAULT_TRIM, locationBuilder );
     }
 
     public static Xpp3Dom build( InputStream is, String encoding )
@@ -68,13 +77,22 @@ public static Xpp3Dom build( InputStream is, String encoding, boolean trim )
 
     public static Xpp3Dom build( Reader reader, boolean trim )
         throws XmlPullParserException, IOException
+    {
+        return build( reader, trim, null );
+    }
+
+    /**
+     * @since 3.2.0
+     */
+    public static Xpp3Dom build( Reader reader, boolean trim, InputLocationBuilder locationBuilder )
+        throws XmlPullParserException, IOException
     {
         try
         {
             final XmlPullParser parser = new MXParser();
             parser.setInput( reader );
 
-            final Xpp3Dom xpp3Dom = build( parser, trim );
+            final Xpp3Dom xpp3Dom = build( parser, trim, locationBuilder );
             reader.close();
             reader = null;
 
@@ -94,6 +112,15 @@ public static Xpp3Dom build( XmlPullParser parser )
 
     public static Xpp3Dom build( XmlPullParser parser, boolean trim )
         throws XmlPullParserException, IOException
+    {
+        return build( parser, trim, null );
+    }
+
+    /**
+     * @since 3.2.0
+     */
+    public static Xpp3Dom build( XmlPullParser parser, boolean trim, InputLocationBuilder locationBuilder )
+        throws XmlPullParserException, IOException
     {
         List<Xpp3Dom> elements = new ArrayList<Xpp3Dom>();
 
@@ -113,6 +140,11 @@ public static Xpp3Dom build( XmlPullParser parser, boolean trim )
 
                 Xpp3Dom childConfiguration = new Xpp3Dom( rawName );
 
+                if ( locationBuilder != null )
+                {
+                    childConfiguration.setInputLocation( locationBuilder.toInputLocation( parser ) );
+                }
+
                 int depth = elements.size();
 
                 if ( depth > 0 )
@@ -194,4 +226,14 @@ else if ( eventType == XmlPullParser.END_TAG )
 
         throw new IllegalStateException( "End of document found before returning to 0 depth" );
     }
+
+    /**
+     * Input location builder interface, to be implemented to choose how to store data.
+     *
+     * @since 3.2.0
+     */
+    public static interface InputLocationBuilder
+    {
+        Object toInputLocation( XmlPullParser parser );
+    }
 }

src/test/java/org/codehaus/plexus/util/xml/Xpp3DomBuilderTest.java

@@ -175,6 +175,35 @@ public void testEscapingInAttributes()
         assertEquals( "Compare stringified DOMs", newString, s );
     }
 
+    @Test
+    public void testInputLocationTracking()
+        throws IOException, XmlPullParserException
+    {
+        Xpp3DomBuilder.InputLocationBuilder ilb = new Xpp3DomBuilder.InputLocationBuilder() {
+            public Object toInputLocation( XmlPullParser parser )
+            {
+                return parser.getLineNumber(); // store only line number as a simple Integer
+            }
+
+        };
+        Xpp3Dom dom = Xpp3DomBuilder.build( new StringReader( createDomString() ), true, ilb );
+        Xpp3Dom expectedDom = createExpectedDom();
+        assertEquals( "root input location", expectedDom.getInputLocation(), dom.getInputLocation() );
+        for( int i = 0; i < dom.getChildCount(); i++ )
+        {
+            Xpp3Dom elt = dom.getChild( i );
+            Xpp3Dom expectedElt = expectedDom.getChild( i );
+            assertEquals( elt.getName() + " input location", expectedElt.getInputLocation(), elt.getInputLocation() );
+
+            if ( "el2".equals( elt.getName() ) )
+            {
+                Xpp3Dom el3 = elt.getChild( 0 );
+                Xpp3Dom expectedEl3 = expectedElt.getChild( 0 );
+                assertEquals( el3.getName() + " input location", expectedEl3.getInputLocation(), el3.getInputLocation() );
+            }
+        }
+    }
+
     private static String getAttributeEncodedString()
     {
         StringBuilder domString = new StringBuilder();
@@ -237,23 +266,33 @@ private static String createDomString()
 
     private static Xpp3Dom createExpectedDom()
     {
+        int line = 1;
         Xpp3Dom expectedDom = new Xpp3Dom( "root" );
+        expectedDom.setInputLocation( line );
         Xpp3Dom el1 = new Xpp3Dom( "el1" );
+        el1.setInputLocation( ++line );
         el1.setValue( "element1" );
         expectedDom.addChild( el1 );
+        ++line; // newline trimmed in Xpp3Dom but not in source
         Xpp3Dom el2 = new Xpp3Dom( "el2" );
+        el2.setInputLocation( ++line );
         el2.setAttribute( "att2", "attribute2\nnextline" );
         expectedDom.addChild( el2 );
         Xpp3Dom el3 = new Xpp3Dom( "el3" );
+        el3.setInputLocation( ++line );
         el3.setAttribute( "att3", "attribute3" );
         el3.setValue( "element3" );
         el2.addChild( el3 );
+        ++line;
         Xpp3Dom el4 = new Xpp3Dom( "el4" );
+        el4.setInputLocation( ++line );
         el4.setValue( "" );
         expectedDom.addChild( el4 );
         Xpp3Dom el5 = new Xpp3Dom( "el5" );
+        el5.setInputLocation( ++line );
         expectedDom.addChild( el5 );
         Xpp3Dom el6 = new Xpp3Dom( "el6" );
+        el6.setInputLocation( ++line );
         el6.setAttribute( "xml:space", "preserve" );
         el6.setValue( "  do not trim  " );
         expectedDom.addChild( el6 );