Use the Expat library directly instead of relying on expatpp

And now we handle namespaces, yay.
And a nice little test.

src/xmpp/xmpp_parser.hpp

@@ -1,35 +1,43 @@
 #ifndef XMPP_PARSER_INCLUDED
 # define XMPP_PARSER_INCLUDED
 
-#include <functional>
-#include <stack>
-
 #include <xmpp/xmpp_stanza.hpp>
 
-#include <expatpp.h>
+#include <functional>
+
+#include <expat.h>
 
 /**
  * A SAX XML parser that builds XML nodes and spawns events when a complete
  * stanza is received (an element of level 2), or when the document is
- * opened (an element of level 1)
+ * opened/closed (an element of level 1)
  *
  * After a stanza_event has been spawned, we delete the whole stanza. This
  * means that even with a very long document (in XMPP the document is
- * potentially infinite), the memory then is never exhausted as long as each
+ * potentially infinite), the memory is never exhausted as long as each
  * stanza is reasonnably short.
  *
+ * The element names generated by expat contain the namespace of the
+ * element, a colon (':') and then the actual name of the element.  To get
+ * an element "x" with a namespace of "http://jabber.org/protocol/muc", you
+ * just look for an XmlNode named "http://jabber.org/protocol/muc:x"
+ *
  * TODO: enforce the size-limit for the stanza (limit the number of childs
  * it can contain). For example forbid the parser going further than level
  * 20 (arbitrary number here), and each XML node to have more than 15 childs
  * (arbitrary number again).
  */
-class XmppParser: public expatpp
+class XmppParser
 {
 public:
   explicit XmppParser();
   ~XmppParser();
 
 public:
+  /**
+   * Feed the parser with some XML data
+   */
+  void feed(const char* data, const int len, const bool is_final);
   /**
    * Add one callback for the various events that this parser can spawn.
    */
@@ -37,7 +45,6 @@ public:
   void add_stream_open_callback(std::function<void(const XmlNode&)>&& callback);
   void add_stream_close_callback(std::function<void(const XmlNode&)>&& callback);
 
-private:
   /**
    * Called when a new XML element has been opened. We instanciate a new
    * XmlNode and set it as our current node. The parent of this new node is
@@ -46,7 +53,7 @@ private:
    *
    * We spawn a stream_event with this node if this is a level-1 element.
    */
-  void startElement(const XML_Char* name, const XML_Char** attribute);
+  void start_element(const XML_Char* name, const XML_Char** attribute);
   /**
    * Called when an XML element has been closed. We close the current_node,
    * set our current_node as the parent of the current_node, and if that was
@@ -55,19 +62,11 @@ private:
    * And we then delete the stanza (and everything under it, its children,
    * attribute, etc).
    */
-  void endElement(const XML_Char* name);
+  void end_element(const XML_Char* name);
   /**
    * Some inner or tail data has been parsed
    */
-  void charData(const XML_Char* data, int len);
-  /**
-   * TODO use that.
-   */
-  void startNamespace(const XML_Char* prefix, const XML_Char* uri);
-  /**
-   * TODO and that.
-   */
-  void endNamespace(const XML_Char* prefix);
+  void char_data(const XML_Char* data, int len);
   /**
    * Calls all the stanza_callbacks one by one.
    */
@@ -82,6 +81,11 @@ private:
    */
   void stream_close_event(const XmlNode& node) const;
 
+private:
+  /**
+   * Expat structure.
+   */
+  XML_Parser parser;
   /**
    * The current depth in the XML document
    */
@@ -98,10 +102,6 @@ private:
   std::vector<std::function<void(const Stanza&)>> stanza_callbacks;
   std::vector<std::function<void(const XmlNode&)>> stream_open_callbacks;
   std::vector<std::function<void(const XmlNode&)>> stream_close_callbacks;
-  /**
-   * TODO: also use that.
-   */
-  std::stack<std::pair<std::string, std::string>> namespaces;
 };
 
 #endif // XMPP_PARSER_INCLUDED