X-Git-Url: http://git.tdb.fi/?a=blobdiff_plain;f=source%2Floader.h;h=8d26a418a0f5d9cdec52a6ecc85160ff4ee1c4e4;hb=92644bf892df1220c8df67e1fc3da85dd02c53c5;hp=7d5d8d9690dfd1c9460739e7a22332a26e6d5e42;hpb=c4930d8d15a5a248ca921e0ed3f9bca8aa18b322;p=libs%2Fdatafile.git

diff --git a/source/loader.h b/source/loader.h
index 7d5d8d9..8d26a41 100644
--- a/source/loader.h
+++ b/source/loader.h
@@ -10,7 +10,7 @@ Distributed under the LGPL
 
 #include <fstream>
 #include <map>
-#include "error.h"
+#include "except.h"
 #include "parser.h"
 #include "statement.h"
 #include "value.h"
@@ -168,6 +168,24 @@ private:
 };
 
 
+template<typename L, typename T0>
+class LoadValue1<L, T0 *>: public LoaderAction
+{
+public:
+	typedef T0 *L::*Pointer0Type;
+
+	LoadValue1(Pointer0Type p0): ptr0(p0) { }
+	void execute(Loader &l, const Statement &st) const
+	{
+		if(st.args.size()!=1) throw TypeError(st.get_location()+": Wrong number of arguments");
+		typename L::Loader &ldr=dynamic_cast<typename L::Loader &>(l);
+		ldr.get_object().*ptr0=&ldr.get_collection().template get<T0>(st.args[0].get<std::string>());
+	}
+private:
+	Pointer0Type ptr0;
+};
+
+
 template<typename L, typename T0, typename T1>
 class LoadValue2: public LoaderAction
 {
@@ -189,11 +207,13 @@ private:
 
 
 /**
-Base class for data loaders.  To enable objects of a certain class to be loaded
-from datafiles, create a public Loader class in it, derived from this class.
-Typically the Loader class contains a reference to the object being loaded.  If
-you want to load data members of the object directly, the Loader class must
-have a member function get_object() returning that reference.
+Base class for data loaders.  To give loading capabilities to a class, create a
+public Loader class in it, derived from this class.  Typically a loader object
+contains a reference to the loaded object.  To make use of loading directly
+into data members, the Loader class must have a get_object() member function,
+returning that reference.  If direct loading of pointers is desired, the Loader
+class must also have a get_collection() member function, returning a collection
+to get pointers from.
 */
 class Loader
 {
@@ -214,40 +234,49 @@ public:
 protected:
 	Loader(): cur_st(0) { }
 
+	/**
+	Adds a keyword that is loaded with a zero-argument function.
+	*/
 	template<typename L>
 	void add(const std::string &k, void (L::*func)())
-	{ actions.insert(typename ActionMap::value_type(k, new LoaderFunc0<L>(func))); }
+	{ add(k, new LoaderFunc0<L>(func)); }
 
 	template<typename L, typename A0>
 	void add(const std::string &k, void (L::*func)(A0))
-	{ actions.insert(typename ActionMap::value_type(k, new LoaderFunc1<L, A0>(func))); }
+	{ add(k, new LoaderFunc1<L, A0>(func)); }
 
 	template<typename L, typename A0, typename A1>
 	void add(const std::string &k, void (L::*func)(A0, A1))
-	{ actions.insert(typename ActionMap::value_type(k, new LoaderFunc2<L, A0, A1>(func))); }
+	{ add(k, new LoaderFunc2<L, A0, A1>(func)); }
 
 	template<typename L, typename A0, typename A1, typename A2>
 	void add(const std::string &k, void (L::*func)(A0, A1, A2))
-	{ actions.insert(typename ActionMap::value_type(k, new LoaderFunc3<L, A0, A1, A2>(func))); }
+	{ add(k, new LoaderFunc3<L, A0, A1, A2>(func)); }
 
 	template<typename L, typename A0, typename A1, typename A2, typename A3>
 	void add(const std::string &k, void (L::*func)(A0, A1, A2, A3))
-	{ actions.insert(typename ActionMap::value_type(k, new LoaderFunc4<L, A0, A1, A2, A3>(func))); }
+	{ add(k, new LoaderFunc4<L, A0, A1, A2, A3>(func)); }
 
+	/**
+	Adds a keyword that is loaded into a variable of the loaded object.
+	*/
 	template<typename L, typename T0>
 	void add(const std::string &k, T0 L::*p0)
-	{ actions.insert(typename ActionMap::value_type(k, new LoadValue1<L, T0>(p0))); }
+	{ add(k, new LoadValue1<L, T0>(p0)); }
 
 	template<typename L, typename T0, typename T1>
 	void add(const std::string &k, T0 L::*p0, T1 L::*p1)
-	{ actions.insert(typename ActionMap::value_type(k, new LoadValue2<L, T0, T1>(p0, p1))); }
+	{ add(k, new LoadValue2<L, T0, T1>(p0, p1)); }
 
+	/**
+	Adds a keyword that is recognized but ignored.
+	*/
 	void add(const std::string &k)
-	{ actions.insert(ActionMap::value_type(k, 0)); }
+	{ add(k, 0); }
 
 	/**
-	Loads a sub-object from the statement being currently processed.  The Loader
-	class of the sub-object is automatically used.
+	Loads a sub-object from the statement being processed.  The Loader class of
+	the sub-object is automatically used.
 	*/
 	template<typename S>
 	void load_sub(S &s)
@@ -265,6 +294,10 @@ protected:
 		loader.load(*cur_st);
 	}
 
+	template<typename S, typename T>
+	void load_sub(S &s, T &p)
+	{ load_sub<typename S::Loader, S, T>(s, p); }
+
 	/**
 	Loads a sub-object with a custom Loader class that takes one argument in
 	addition to to object to be loaded.
@@ -277,12 +310,25 @@ protected:
 		L loader(s, p);
 		loader.load(*cur_st);
 	}
+
+	/**
+	Returns the source of the statement being processed.  This can be used to
+	implement relative paths in include-like statements.  Note that the source
+	may not necessarily be a file.
+	*/
+	const std::string &get_source() const
+	{
+		if(!cur_st)
+			throw InvalidState("get_source called without current statement");
+		return cur_st->source;
+	}
 private:
 	typedef std::map<std::string, LoaderAction *> ActionMap;
 
 	ActionMap       actions;
 	const Statement *cur_st;
 
+	void add(const std::string &, LoaderAction *);
 	void load_statement(const Statement &st);
 };
 
@@ -301,6 +347,18 @@ void load(T &obj, const std::string &fn)
 	loader.load(parser);
 }
 
+template<typename T, typename U>
+void load(T &obj, const std::string &fn, U arg)
+{
+	std::ifstream in(fn.c_str());
+	if(!in)
+		throw Exception("Couldn't open "+fn);
+
+	Parser parser(in, fn);
+	typename T::Loader loader(obj, arg);
+	loader.load(parser);
+}
+
 } // namespace DataFile
 } // namespace Msp