GEOS-11850 Pretty-print text/mapml responses based on GeoServer global verbose setting

Author: prushforth

doc/en/user/source/extensions/mapml/images/mapml_global_menu.png

@@ -80,7 +80,14 @@ For example, the UTM14WGS84Quad specified in the above selector has the followin
 
 .. figure:: images/mapml_utm_gridset.png
 
+Global Settings
+---------------
+
+.. figure:: images/mapml_global_menu.png
+
+The Global settings menu (above) contains a Service Response Settings section (below) which contains the Verbose XML output (pretty print) checkbox. The MapML extension respects or uses this setting when serializing text/mapml (media type) responses.  Be aware that caching on both the client and server may prevent this setting from becoming immediately obvious in devtools responses. Refreshing the browser cache can request a new version of the response, but if the response is cached on the server, for example as a vector tile, it may not be possible to obtain a pretty printed version of the data, short of deleting the tile cache, which may be undesirable.
 
+.. figure:: images/mapml_global_verbose_output.png
 
 Styles
 ------

doc/en/user/source/extensions/mapml/images/mapml_global_verbose_output.png

@@ -51,10 +51,23 @@ private Marshaller createMarshaller() throws JAXBException {
      * @param output OutputStream
      */
     public void encode(Mapml mapml, OutputStream output) {
+        encode(mapml, output, false);
+    }
+
+    /**
+     * Use Marshaller to encode MapML object onto an output stream with optional pretty-printing
+     *
+     * @param mapml MapML object
+     * @param output OutputStream
+     * @param prettyPrint true to enable pretty-printing with 2-space indents, false for dense markup
+     */
+    public void encode(Mapml mapml, OutputStream output, boolean prettyPrint) {
         try {
-            XMLStreamWriter writer = new Wrapper(XMLOutputFactory.newInstance().createXMLStreamWriter(output));
-            createMarshaller().marshal(mapml, writer);
-            writer.flush();
+            XMLOutputFactory factory = XMLOutputFactory.newInstance();
+            Wrapper wrapper = new Wrapper(factory.createXMLStreamWriter(output));
+            wrapper.setIndenting(prettyPrint);
+            createMarshaller().marshal(mapml, wrapper);
+            wrapper.flush();
         } catch (JAXBException | XMLStreamException e) {
             throw new ServiceException(e);
         }
@@ -81,6 +94,13 @@ static class Wrapper implements XMLStreamWriter {
 
         private final XMLStreamWriter writer;
         private static final String NS_PREFIX = "";
+        public static final String MAPML_INDENT_PROPERTY = "mapml.indent";
+        private static final String INDENT = "  ";
+
+        private boolean indenting = false;
+        private int depth = 0;
+        private boolean needsIndent = false;
+        private boolean lastWasStartElement = false;
 
         /**
          * Constructor
@@ -91,39 +111,90 @@ static class Wrapper implements XMLStreamWriter {
             this.writer = writer;
         }
 
+        /** Writes indentation if pretty-printing is enabled */
+        private void writeIndent() throws XMLStreamException {
+            if (indenting && needsIndent) {
+                writer.writeCharacters("\n");
+                for (int i = 0; i < depth; i++) {
+                    writer.writeCharacters(INDENT);
+                }
+                needsIndent = false;
+            }
+        }
+
         @Override
         public void writeStartElement(String localName) throws XMLStreamException {
+            writeIndent();
             writer.writeStartElement(localName);
+            depth++;
+            needsIndent = true;
+            lastWasStartElement = true;
         }
 
         @Override
         public void writeStartElement(String namespaceURI, String localName) throws XMLStreamException {
+            writeIndent();
             writer.writeStartElement(namespaceURI, localName);
+            depth++;
+            needsIndent = true;
+            lastWasStartElement = true;
         }
 
         @Override
         public void writeStartElement(String prefix, String localName, String namespaceURI) throws XMLStreamException {
+            writeIndent();
             writer.writeStartElement(NS_PREFIX, localName, namespaceURI);
+            depth++;
+            needsIndent = true;
+            lastWasStartElement = true;
         }
 
         @Override
         public void writeEmptyElement(String namespaceURI, String localName) throws XMLStreamException {
-            writer.writeEmptyElement(namespaceURI, localName);
+            // Force HTML-compatible empty elements with explicit end tags
+            writeIndent();
+            writer.writeStartElement(namespaceURI, localName);
+            writer.writeEndElement();
+            needsIndent = true;
         }
 
         @Override
         public void writeEmptyElement(String prefix, String localName, String namespaceURI) throws XMLStreamException {
-            writer.writeEmptyElement(prefix, localName, namespaceURI);
+            // Force HTML-compatible empty elements with explicit end tags
+            writeIndent();
+            writer.writeStartElement(NS_PREFIX, localName, namespaceURI);
+            writer.writeEndElement();
+            needsIndent = true;
         }
 
         @Override
         public void writeEmptyElement(String localName) throws XMLStreamException {
-            writer.writeEmptyElement(localName);
+            // Force HTML-compatible empty elements with explicit end tags
+            writeIndent();
+            writer.writeStartElement(localName);
+            writer.writeEndElement();
+            needsIndent = true;
         }
 
         @Override
         public void writeEndElement() throws XMLStreamException {
+            depth--;
+            // For empty elements (start immediately followed by end), keep on same line
+            if (needsIndent && !lastWasStartElement) {
+                writeIndent();
+            } else if (lastWasStartElement) {
+                // Note: empty string typically doesn't add content but signals "non-empty" to writer
+                writer.writeCharacters("");
+            }
             writer.writeEndElement();
+
+            // Add two newlines after the root closing tag
+            if (depth == 0 && indenting) {
+                writer.writeCharacters("\n\n");
+            }
+
+            needsIndent = true;
+            lastWasStartElement = false;
         }
 
         @Override
@@ -169,7 +240,9 @@ public void writeDefaultNamespace(String namespaceURI) throws XMLStreamException
 
         @Override
         public void writeComment(String data) throws XMLStreamException {
+            writeIndent();
             writer.writeComment(data);
+            needsIndent = true;
         }
 
         @Override
@@ -214,11 +287,17 @@ public void writeStartDocument(String encoding, String version) throws XMLStream
 
         @Override
         public void writeCharacters(String text) throws XMLStreamException {
+            // Don't indent before text content as it would alter the actual content
+            needsIndent = false;
+            lastWasStartElement = false;
             writer.writeCharacters(text);
         }
 
         @Override
         public void writeCharacters(char[] text, int start, int len) throws XMLStreamException {
+            // Don't indent before text content as it would alter the actual content
+            needsIndent = false;
+            lastWasStartElement = false;
             writer.writeCharacters(text, start, len);
         }
 
@@ -249,7 +328,28 @@ public NamespaceContext getNamespaceContext() {
 
         @Override
         public Object getProperty(String name) throws IllegalArgumentException {
+            if (MAPML_INDENT_PROPERTY.equals(name)) {
+                return indenting;
+            }
             return writer.getProperty(name);
         }
+
+        /**
+         * Sets the indenting property for pretty-printing
+         *
+         * @param indent true to enable pretty-printing with 2-space indents, false for dense markup
+         */
+        public void setIndenting(boolean indent) {
+            this.indenting = indent;
+        }
+
+        /**
+         * Gets the current indenting state
+         *
+         * @return true if pretty-printing is enabled
+         */
+        public boolean isIndenting() {
+            return indenting;
+        }
     }
 }

doc/en/user/source/extensions/mapml/installation.rst

@@ -7,7 +7,6 @@
 
 import java.io.IOException;
 import java.io.OutputStream;
-import java.io.OutputStreamWriter;
 import java.util.HashMap;
 import java.util.Iterator;
 import java.util.List;
@@ -16,8 +15,6 @@
 import java.util.function.Function;
 import java.util.logging.Level;
 import java.util.logging.Logger;
-import javax.xml.transform.Result;
-import javax.xml.transform.stream.StreamResult;
 import net.opengis.wfs.FeatureCollectionType;
 import org.geoserver.catalog.Catalog;
 import org.geoserver.catalog.FeatureTypeInfo;
@@ -47,7 +44,6 @@
 import org.geotools.feature.FeatureCollection;
 import org.geotools.util.logging.Logging;
 import org.springframework.beans.factory.annotation.Autowired;
-import org.springframework.oxm.jaxb.Jaxb2Marshaller;
 
 /**
  * @author Chris Hodgson
@@ -57,7 +53,7 @@ public class MapMLGetFeatureInfoOutputFormat extends GetFeatureInfoOutputFormat
     private static final Logger LOGGER = Logging.getLogger("org.geoserver.mapml");
 
     @Autowired
-    private Jaxb2Marshaller mapmlMarshaller;
+    private MapMLEncoder mapMLEncoder;
 
     private WMS wms;
 
@@ -157,10 +153,9 @@ public void write(FeatureCollectionType results, GetFeatureInfoRequest request,
             }
         }
 
-        OutputStreamWriter osw = new OutputStreamWriter(out, wms.getCharSet());
-        Result result = new StreamResult(osw);
-        mapmlMarshaller.marshal(mapml, result);
-        osw.flush();
+        // write to output based on global verbose setting
+        boolean verbose = wms.getGeoServer().getGlobal().getSettings().isVerbose();
+        mapMLEncoder.encode(mapml, out, verbose);
     }
 
     @Override

src/extension/mapml/src/main/java/org/geoserver/mapml/MapMLEncoder.java

@@ -7,14 +7,11 @@
 
 import java.io.IOException;
 import java.io.OutputStream;
-import java.io.OutputStreamWriter;
 import java.net.URI;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
 import java.util.logging.Logger;
-import javax.xml.transform.Result;
-import javax.xml.transform.stream.StreamResult;
 import net.opengis.wfs.impl.GetFeatureTypeImpl;
 import net.opengis.wfs.impl.QueryTypeImpl;
 import org.geoserver.catalog.LayerInfo;
@@ -32,7 +29,6 @@
 import org.geotools.referencing.CRS;
 import org.geotools.util.logging.Logging;
 import org.springframework.beans.factory.annotation.Autowired;
-import org.springframework.oxm.jaxb.Jaxb2Marshaller;
 
 /**
  * @author Chris Hodgson
@@ -42,7 +38,7 @@ public class MapMLGetFeatureOutputFormat extends WFSGetFeatureOutputFormat {
     private static final Logger LOGGER = Logging.getLogger(MapMLGetFeatureOutputFormat.class);
 
     @Autowired
-    private Jaxb2Marshaller mapmlMarshaller;
+    private MapMLEncoder mapMLEncoder;
 
     private String base;
     private String path;
@@ -97,11 +93,9 @@ protected void write(FeatureCollectionResponse featureCollectionResponse, Output
                 null,
                 null);
 
-        // write to output
-        OutputStreamWriter osw = new OutputStreamWriter(out, gs.getSettings().getCharset());
-        Result result = new StreamResult(osw);
-        mapmlMarshaller.marshal(mapml, result);
-        osw.flush();
+        // write to output based on global verbose setting
+        boolean verbose = gs.getGlobal().getSettings().isVerbose();
+        mapMLEncoder.encode(mapml, out, verbose);
     }
 
     /**

src/extension/mapml/src/main/java/org/geoserver/mapml/MapMLGetFeatureInfoOutputFormat.java

@@ -73,7 +73,9 @@ public WebMap produceMap(WMSMapContent mapContent) throws ServiceException, IOEx
             mapMLDocument = mapMLDocumentBuilder.getMapMLDocument();
         }
         ByteArrayOutputStream bos = new ByteArrayOutputStream();
-        encoder.encode(mapMLDocument, bos);
+        // write to output based on global verbose setting
+        boolean verbose = geoServer.getGlobal().getSettings().isVerbose();
+        encoder.encode(mapMLDocument, bos, verbose);
         return new RawMap(mapContent, bos, MapMLConstants.MAPML_MIME_TYPE);
     }
 

src/extension/mapml/src/main/java/org/geoserver/mapml/MapMLGetFeatureOutputFormat.java

@@ -5,16 +5,12 @@
 package org.geoserver.mapml;
 
 import java.io.IOException;
-import java.io.OutputStreamWriter;
 import java.io.UnsupportedEncodingException;
-import javax.xml.transform.Result;
-import javax.xml.transform.stream.StreamResult;
 import org.geoserver.rest.converters.BaseMessageConverter;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.http.HttpOutputMessage;
 import org.springframework.http.MediaType;
 import org.springframework.lang.Nullable;
-import org.springframework.oxm.jaxb.Jaxb2Marshaller;
 
 /**
  * @author Chris Hodgson
@@ -23,7 +19,7 @@
 public class MapMLMessageConverter extends BaseMessageConverter<Object> {
 
     @Autowired
-    private Jaxb2Marshaller mapmlMarshaller;
+    private MapMLEncoder mapMLEncoder;
 
     /** */
     public MapMLMessageConverter() {
@@ -47,7 +43,7 @@ public boolean canRead(Class<?> clazz, @Nullable MediaType mediaType) {
      */
     @Override
     public boolean canWrite(Class<?> clazz, @Nullable MediaType mediaType) {
-        return canWrite(mediaType) && mapmlMarshaller.supports(clazz);
+        return canWrite(mediaType) && org.geoserver.mapml.xml.Mapml.class.isAssignableFrom(clazz);
     }
 
     /**
@@ -69,11 +65,12 @@ protected boolean supports(Class<?> clazz) {
     @Override
     protected void writeInternal(Object o, HttpOutputMessage outputMessage)
             throws UnsupportedEncodingException, IOException {
-        try (OutputStreamWriter osw = new OutputStreamWriter(
-                outputMessage.getBody(), geoServer.getSettings().getCharset())) {
-            Result result = new StreamResult(osw);
-            mapmlMarshaller.marshal(o, result);
-            osw.flush();
+        if (o instanceof org.geoserver.mapml.xml.Mapml) {
+            // write to output based on global verbose setting
+            boolean verbose = geoServer.getGlobal().getSettings().isVerbose();
+            mapMLEncoder.encode((org.geoserver.mapml.xml.Mapml) o, outputMessage.getBody(), verbose);
+        } else {
+            throw new IllegalArgumentException("Can only write Mapml objects, got: " + o.getClass());
         }
     }
 }