Make PubSub's SimplePayload infer the XML Element name and namespace

Fixes SMACK-816.

smack-core/src/main/java/org/jivesoftware/smack/util/ParserUtils.java

@@ -1,6 +1,6 @@
 /**
  *
- * Copyright © 2014-2017 Florian Schmaus
+ * Copyright © 2014-2018 Florian Schmaus
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -23,6 +23,9 @@ import java.text.ParseException;
 import java.util.Date;
 import java.util.Locale;
 
+import javax.xml.XMLConstants;
+import javax.xml.namespace.QName;
+
 import org.jivesoftware.smack.SmackException;
 
 import org.jxmpp.jid.EntityBareJid;
@@ -250,4 +253,14 @@ public class ParserUtils {
     public static String getXmlLang(XmlPullParser parser) {
         return parser.getAttributeValue("http://www.w3.org/XML/1998/namespace", "lang");
     }
+
+    public static QName getQName(XmlPullParser parser) {
+        String elementName = parser.getName();
+        String prefix = parser.getPrefix();
+        if (prefix == null) {
+            prefix = XMLConstants.DEFAULT_NS_PREFIX;
+        }
+        String namespace = parser.getNamespace();
+        return new QName(namespace, elementName, prefix);
+    }
 }

smack-extensions/src/main/java/org/jivesoftware/smackx/pubsub/SimplePayload.java

@@ -16,7 +16,17 @@
  */
 package org.jivesoftware.smackx.pubsub;
 
+import java.io.IOException;
+
+import javax.xml.namespace.QName;
+
 import org.jivesoftware.smack.packet.ExtensionElement;
+import org.jivesoftware.smack.util.PacketParserUtils;
+import org.jivesoftware.smack.util.ParserUtils;
+import org.jivesoftware.smack.util.StringUtils;
+
+import org.xmlpull.v1.XmlPullParser;
+import org.xmlpull.v1.XmlPullParserException;
 
 /**
  * The default payload representation for {@link PayloadItem#getPayload()}.  It simply 
@@ -27,7 +37,29 @@ import org.jivesoftware.smack.packet.ExtensionElement;
 public class SimplePayload implements ExtensionElement {
     private final String elemName;
     private final String ns;
-    private final CharSequence payload;
+    private final String payload;
+
+    /**
+     * Construct a <tt>SimplePayload</tt> object with the specified element name,
+     * namespace and content.  The content must be well formed XML.
+     *
+     * @param xmlPayload The payload data
+     */
+    public SimplePayload(String xmlPayload) {
+        XmlPullParser parser;
+        try {
+            parser = PacketParserUtils.getParserFor(xmlPayload);
+        }
+        catch (XmlPullParserException | IOException e) {
+            throw new AssertionError(e);
+        }
+        QName qname = ParserUtils.getQName(parser);
+
+        payload = xmlPayload;
+
+        elemName = StringUtils.requireNotNullOrEmpty(qname.getLocalPart(), "Could not determine element name from XML payload");
+        ns = StringUtils.requireNotNullOrEmpty(qname.getNamespaceURI(), "Could not determine namespace from XML payload");
+    }
 
     /**
      * Construct a <tt>SimplePayload</tt> object with the specified element name, 
@@ -36,11 +68,18 @@ public class SimplePayload implements ExtensionElement {
      * @param elementName The root element name (of the payload)
      * @param namespace The namespace of the payload, null if there is none
      * @param xmlPayload The payload data
+     * @deprecated use {@link #SimplePayload(String)} insteas.
      */
+    // TODO: Remove in Smack 4.5
+    @Deprecated
     public SimplePayload(String elementName, String namespace, CharSequence xmlPayload) {
-        elemName = elementName;
-        payload = xmlPayload;
-        ns = namespace;
+        this(xmlPayload.toString());
+        if (!elementName.equals(this.elemName)) {
+            throw new IllegalArgumentException();
+        }
+        if (!namespace.equals(this.ns)) {
+            throw new IllegalArgumentException();
+        }
     }
 
     @Override
@@ -54,7 +93,7 @@ public class SimplePayload implements ExtensionElement {
     }
 
     @Override
-    public CharSequence toXML() {
+    public String toXML() {
         return payload;
     }
 

smack-extensions/src/main/java/org/jivesoftware/smackx/pubsub/provider/ItemProvider.java

@@ -59,7 +59,7 @@ public class ItemProvider extends ExtensionElementProvider<Item>  {
             if (extensionProvider == null) {
                 // TODO: Should we use StandardExtensionElement in this case? And probably remove SimplePayload all together.
                 CharSequence payloadText = PacketParserUtils.parseElement(parser, true);
-                return new PayloadItem<>(itemNamespace, id, node, new SimplePayload(payloadElemName, payloadNS, payloadText));
+                return new PayloadItem<>(itemNamespace, id, node, new SimplePayload(payloadText.toString()));
             }
             else {
                 return new PayloadItem<>(itemNamespace, id, node, extensionProvider.parse(parser));

smack-extensions/src/test/java/org/jivesoftware/smackx/pubsub/ItemValidationTest.java

@@ -75,7 +75,7 @@ public class ItemValidationTest extends InitExtensions {
 
     @Test
     public void verifyPayloadItem() throws Exception {
-        SimplePayload payload = new SimplePayload(null, null, "<data>This is the payload</data>");
+        SimplePayload payload = new SimplePayload("<data xmlns='https://example.org'>This is the payload</data>");
 
         PayloadItem<SimplePayload> simpleItem = new PayloadItem<>(payload);
         String simpleCtrl = "<item xmlns='http://jabber.org/protocol/pubsub'>" + payload.toXML() + "</item>";

smack-extensions/src/test/java/org/jivesoftware/smackx/pubsub/SimplePayloadTest.java

@@ -0,0 +1,34 @@
+/**
+ *
+ * Copyright 2018 Florian Schmaus
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.jivesoftware.smackx.pubsub;
+
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Test;
+
+public class SimplePayloadTest {
+
+    @Test
+    public void simplePayloadTest() {
+        String xmlPayload = "<element xmlns='https://example.org'><foo>Test</foo><bar/></element>";
+        SimplePayload simplePayload = new SimplePayload(xmlPayload);
+
+        assertEquals("element", simplePayload.getElementName());
+        assertEquals("https://example.org", simplePayload.getNamespace());
+        assertEquals(xmlPayload, simplePayload.toXML());
+    }
+}