Major update to rename ContentObject to Data everywhere.
diff --git a/ndn-cpp/c/encoding/binary-xml-data.c b/ndn-cpp/c/encoding/binary-xml-data.c
new file mode 100644
index 0000000..8da14b2
--- /dev/null
+++ b/ndn-cpp/c/encoding/binary-xml-data.c
@@ -0,0 +1,194 @@
+/**
+ * @author: Jeff Thompson
+ * Derived from ContentObject.js by Meki Cheraoui.
+ * See COPYING for copyright and distribution information.
+ */
+
+#include "BinaryXMLEncoder.h"
+#include "BinaryXMLDecoder.h"
+#include "BinaryXMLName.h"
+#include "BinaryXMLPublisherPublicKeyDigest.h"
+#include "binary-xml-data.h"
+
+static ndn_Error encodeSignature(struct ndn_Signature *signature, struct ndn_BinaryXmlEncoder *encoder)
+{
+  ndn_Error error;
+  if (error = ndn_BinaryXmlEncoder_writeElementStartDTag(encoder, ndn_BinaryXml_DTag_Signature))
+    return error;
+  
+  // TODO: Check if digestAlgorithm is the same as the default, and skip it, otherwise encode it as UDATA.
+
+  if (error = ndn_BinaryXmlEncoder_writeOptionalBlobDTagElement
+      (encoder, ndn_BinaryXml_DTag_Witness, signature->witness, signature->witnessLength))
+    return error;
+
+  // Require a signature.
+  if (error = ndn_BinaryXmlEncoder_writeBlobDTagElement
+      (encoder, ndn_BinaryXml_DTag_SignatureBits, signature->signature, signature->signatureLength))
+    return error;
+  
+	if (error = ndn_BinaryXmlEncoder_writeElementClose(encoder))
+    return error;
+  
+  return 0;    
+}
+
+static ndn_Error decodeSignature(struct ndn_Signature *signature, struct ndn_BinaryXmlDecoder *decoder)
+{
+  ndn_Error error;
+  if (error = ndn_BinaryXmlDecoder_readElementStartDTag(decoder, ndn_BinaryXml_DTag_Signature))
+    return error;
+  
+  /* TODO: digestAlgorithm as UDATA */ signature->digestAlgorithm = 0; signature->digestAlgorithmLength = 0;
+  
+  if (error = ndn_BinaryXmlDecoder_readOptionalBinaryDTagElement
+      (decoder, ndn_BinaryXml_DTag_Witness, 0, &signature->witness, &signature->witnessLength))
+    return error;
+  
+  // Require a signature.
+  if (error = ndn_BinaryXmlDecoder_readBinaryDTagElement
+      (decoder, ndn_BinaryXml_DTag_SignatureBits, 0, &signature->signature, &signature->signatureLength))
+    return error;
+  
+  if (error = ndn_BinaryXmlDecoder_readElementClose(decoder))
+    return error;
+  
+  return 0;
+}
+
+static ndn_Error encodeSignedInfo(struct ndn_SignedInfo *signedInfo, struct ndn_BinaryXmlEncoder *encoder)
+{
+  if (signedInfo->type < 0)
+    return;
+
+  ndn_Error error;
+  if (error = ndn_BinaryXmlEncoder_writeElementStartDTag(encoder, ndn_BinaryXml_DTag_SignedInfo))
+    return error;
+
+  // This will skip encoding if there is no publisherPublicKeyDigest.
+  if (error = ndn_encodeBinaryXmlPublisherPublicKeyDigest(&signedInfo->publisherPublicKeyDigest, encoder))
+    return error;
+  
+  if (error = ndn_BinaryXmlEncoder_writeOptionalTimeMillisecondsDTagElement
+      (encoder, ndn_BinaryXml_DTag_Timestamp, signedInfo->timestampMilliseconds))
+    return error;
+  
+  if (signedInfo->type != ndn_ContentType_DATA) {
+    // Not the default of DATA, so we need to encode the type.
+    // TODO: Implement converting the type from an int and encoding.
+  }
+  
+  if (error = ndn_BinaryXmlEncoder_writeOptionalUnsignedDecimalIntDTagElement
+      (encoder, ndn_BinaryXml_DTag_FreshnessSeconds, signedInfo->freshnessSeconds))
+    return error;
+  
+  if (error = ndn_BinaryXmlEncoder_writeOptionalBlobDTagElement
+      (encoder, ndn_BinaryXml_DTag_FinalBlockID, signedInfo->finalBlockID, signedInfo->finalBlockIDLength))
+    return error;
+ 
+  // This will skip encoding if there is no key locator.
+  if (error = ndn_encodeBinaryXmlKeyLocator(&signedInfo->keyLocator, encoder))
+    return error;
+  
+	if (error = ndn_BinaryXmlEncoder_writeElementClose(encoder))
+    return error;
+  
+  return 0;  
+}
+
+static ndn_Error decodeSignedInfo(struct ndn_SignedInfo *signedInfo, struct ndn_BinaryXmlDecoder *decoder)
+{
+  ndn_Error error;
+  if (error = ndn_BinaryXmlDecoder_readElementStartDTag(decoder, ndn_BinaryXml_DTag_SignedInfo))
+    return error;
+  
+  if (error = ndn_decodeOptionalBinaryXmlPublisherPublicKeyDigest(&signedInfo->publisherPublicKeyDigest, decoder))
+    return error;
+  
+  if (error= ndn_BinaryXmlDecoder_readOptionalTimeMillisecondsDTagElement
+      (decoder, ndn_BinaryXml_DTag_Timestamp, &signedInfo->timestampMilliseconds))
+    return error;
+  
+  // TODO: Implement reading the type and converting to an int.
+  signedInfo->type = ndn_ContentType_DATA;
+ 
+  if (error = ndn_BinaryXmlDecoder_readOptionalUnsignedIntegerDTagElement
+      (decoder, ndn_BinaryXml_DTag_FreshnessSeconds, &signedInfo->freshnessSeconds))
+    return error;
+
+  if (error = ndn_BinaryXmlDecoder_readOptionalBinaryDTagElement
+      (decoder, ndn_BinaryXml_DTag_FinalBlockID, 0, &signedInfo->finalBlockID, &signedInfo->finalBlockIDLength))
+    return error;
+
+  if (error = ndn_decodeOptionalBinaryXmlKeyLocator(&signedInfo->keyLocator, decoder))
+    return error;
+  
+  if (error = ndn_BinaryXmlDecoder_readElementClose(decoder))
+    return error;
+  
+  return 0;
+}
+
+ndn_Error ndn_encodeBinaryXmlData(struct ndn_Data *data, struct ndn_BinaryXmlEncoder *encoder)
+{
+  ndn_Error error;
+  if (error = ndn_BinaryXmlEncoder_writeElementStartDTag(encoder, ndn_BinaryXml_DTag_ContentObject))
+    return error;
+  
+  if (error = encodeSignature(&data->signature, encoder))
+    return 0;
+
+  if (error = ndn_encodeBinaryXmlName(&data->name, encoder))
+    return error;
+
+  if (error = encodeSignedInfo(&data->signedInfo, encoder))
+    return 0;
+
+  if (error = ndn_BinaryXmlEncoder_writeBlobDTagElement
+      (encoder, ndn_BinaryXml_DTag_Content, data->content, data->contentLength))
+    return error;
+  
+	if (error = ndn_BinaryXmlEncoder_writeElementClose(encoder))
+    return error;
+  
+  return 0;
+}
+
+ndn_Error ndn_decodeBinaryXmlData(struct ndn_Data *data, struct ndn_BinaryXmlDecoder *decoder)
+{
+  ndn_Error error;
+  if (error = ndn_BinaryXmlDecoder_readElementStartDTag(decoder, ndn_BinaryXml_DTag_ContentObject))
+    return error;
+
+  int gotExpectedTag;
+  if (error = ndn_BinaryXmlDecoder_peekDTag(decoder, ndn_BinaryXml_DTag_Signature, &gotExpectedTag))
+    return error;
+  if (gotExpectedTag) {
+    if (error = decodeSignature(&data->signature, decoder))
+      return error;
+  }
+  else
+    ndn_Signature_init(&data->signature);
+  
+  if (error = ndn_decodeBinaryXmlName(&data->name, decoder))
+    return error;
+  
+  if (error = ndn_BinaryXmlDecoder_peekDTag(decoder, ndn_BinaryXml_DTag_SignedInfo, &gotExpectedTag))
+    return error;
+  if (gotExpectedTag) {
+    if (error = decodeSignedInfo(&data->signedInfo, decoder))
+      return error;
+  }
+  else
+    ndn_SignedInfo_init(&data->signedInfo);
+
+  // Require a Content element, but set allowNull to allow a missing BLOB.
+  if (error = ndn_BinaryXmlDecoder_readBinaryDTagElement
+      (decoder, ndn_BinaryXml_DTag_Content, 1, &data->content, &data->contentLength))
+    return error; 
+  
+  if (error = ndn_BinaryXmlDecoder_readElementClose(decoder))
+    return error;
+  
+  return 0;
+}