xerces-plugin-arrays: add deserialization support for multiple elemen…

…ts with the same parent (map to elektra array) ElektraInitiative#1280

src/plugins/xerces/CMakeLists.txt

@@ -20,6 +20,8 @@ add_plugin (xerces
 		${XercesC_INCLUDE_DIRS}
 	LINK_LIBRARIES
 		${XercesC_LIBRARIES}
+	LINK_ELEKTRA
+		elektra-meta
 	INSTALL_TEST_DATA
 )
 

src/plugins/xerces/deserializer.cpp

@@ -18,9 +18,12 @@
 
 #include <algorithm>
 #include <iostream>
+#include <locale>
+#include <map>
+
+#include <kdbease.h>
 #include <kdblogger.h>
 #include <key.hpp>
-#include <locale>
 
 XERCES_CPP_NAMESPACE_USE
 using namespace std;
@@ -48,10 +51,7 @@ string trim (string const & str)
 	while (getline (ss, to, '\n'))
 	{
 		// Remove whitespace lines, most likely caused by pretty printing
-		if (!all_of (to.begin (), to.end (), [](char c) { return isspace (c, locale ()); }))
-		{
-			trimmed += to;
-		}
+		if (!all_of (to.begin (), to.end (), [](char c) { return isspace (c, locale ()); })) trimmed += to;
 	}
 
 	return trimmed;
@@ -74,10 +74,18 @@ string getElementText (DOMNode const * parent)
 	return trim (str);
 }
 
+Key newNodeKey (Key const & parent, DOMNode const * node)
+{
+	Key childKey (parent.getFullName (), KEY_END);
+	const string keyName = toStr (node->getNodeName ());
+	childKey.addBaseName (keyName);
+	return childKey;
+}
+
 void node2key (DOMNode const * n, Key const & parent, KeySet const & ks, Key & current)
 {
 	const string keyName = toStr (n->getNodeName ());
-	ELEKTRA_LOG_DEBUG ("Encountered Element: %s", keyName.c_str ());
+	ELEKTRA_LOG_DEBUG ("Encountered Element: %s with parent %s", keyName.c_str (), current.getFullName ().c_str ());
 
 	if (!ks.size ())
 	{ // we map the parent key to the xml root element
@@ -90,17 +98,12 @@ void node2key (DOMNode const * n, Key const & parent, KeySet const & ks, Key & c
 		}
 	}
 	else
-	{
 		current.addBaseName (keyName);
-	}
 
 	const string text = getElementText (n);
 	current.set<string> (text);
 
-	if (!current.isValid ())
-	{
-		throw XercesPluginException ("Given keyset contains invalid keys to serialize");
-	}
+	if (!current.isValid ()) throw XercesPluginException ("Given keyset contains invalid keys to serialize");
 
 	ELEKTRA_LOG_DEBUG ("new parent is %s with value %s", current.getFullName ().c_str (), current.get<string> ().c_str ());
 
@@ -119,23 +122,67 @@ void node2key (DOMNode const * n, Key const & parent, KeySet const & ks, Key & c
 	}
 }
 
-void dom2keyset (DOMNode const * n, Key const & parent, KeySet & ks)
+void analyzeMultipleElements (DOMNode const * n, Key const & current, map<Key, bool> & arrays)
+{
+	for (auto child = n->getFirstChild (); child != 0; child = child->getNextSibling ())
+	{
+		Key childKey = newNodeKey (current, child);
+
+		auto it = arrays.find (childKey);
+		if (it != arrays.end ())
+		{
+			if (!it->second)
+			{
+				ELEKTRA_LOG_DEBUG ("There are multiple elements of %s, mapping this as an array",
+						   childKey.getFullName ().c_str ());
+				arrays[childKey] = true;
+			}
+		}
+		else
+			arrays[childKey] = false;
+	}
+}
+
+Key newArrayKey (Key const & arrayKey, KeySet & ks)
+{
+	KeySet result (elektraArrayGet (arrayKey.getKey (), ks.getKeySet ()));
+	if (!result.size ())
+	{
+		Key arrayBaseKey = arrayKey.dup ();
+		arrayBaseKey.addBaseName ("#");
+		result.append (arrayBaseKey);
+	}
+	return Key (elektraArrayGetNextKey (result.getKeySet ()));
+}
+
+void dom2keyset (DOMNode const * n, Key const & parent, KeySet & ks, map<Key, bool> & arrays)
 {
 	if (n)
 	{
 		Key current (parent.getFullName (), KEY_END);
+
 		if (n->getNodeType () == DOMNode::ELEMENT_NODE)
 		{
 			node2key (n, parent, ks, current);
-			// Only add keys with a value, attributes or leafs or the root to preserve the original name
-			if (n->hasAttributes () || !current.getString ().empty () || !n->getFirstChild () || !ks.size ())
+
+			auto it = arrays.find (current);
+			const bool array = it != arrays.end () && it->second;
+			// Multiple elements with that name, map as an array
+			if (array) current = newArrayKey (current, ks);
+
+			// Only add keys with a value, attributes or leafs or the root to preserve the original name or array keys
+			if (n->hasAttributes () || !current.getString ().empty () || !n->getFirstChild () || !ks.size () || array)
 			{
 				ELEKTRA_LOG_DEBUG ("adding %s", current.getFullName ().c_str ());
 				ks.append (current);
 			}
+			else
+				ELEKTRA_LOG_DEBUG ("skipping %s", current.getFullName ().c_str ());
 		}
+		// the first level cannot have more children so its enough to check that here
+		analyzeMultipleElements (n, current, arrays);
 		for (auto child = n->getFirstChild (); child != 0; child = child->getNextSibling ())
-			dom2keyset (child, current, ks);
+			dom2keyset (child, current, ks, arrays);
 	}
 }
 
@@ -149,5 +196,6 @@ void xerces::deserialize (Key const & parentKey, KeySet & ks)
 	ELEKTRA_LOG_DEBUG ("deserializing relative to %s from file %s", parentKey.getFullName ().c_str (),
 			   parentKey.get<string> ().c_str ());
 	auto document = doc2dom (parentKey.get<string> ());
-	if (document) dom2keyset (document->getDocumentElement (), parentKey, ks);
+	map<Key, bool> arrays;
+	if (document) dom2keyset (document->getDocumentElement (), parentKey, ks, arrays);
 }

src/plugins/xerces/xerces/pom.xml

@@ -45,7 +45,7 @@
 			<artifactId>log4j-core</artifactId>
 			<version>2.0-rc2</version>
 		</dependency>
-		<!-- <dependency>
+		<dependency>
 			<groupId>joda-time</groupId>
 			<artifactId>joda-time</artifactId>
 			<version>2.3</version>