Add more flexible versions of the load function

[libs/datafile.git] / source / loader.h

diff --git a/source/loader.h b/source/loader.h
index 4ea7994e757f76476dda000f20c67fa44e21fee9..207ecff8dff8d7f068aa033994ef2a5e608ba56a 100644 (file)
--- a/source/loader.h
+++ b/source/loader.h
@@ -3,8 +3,8 @@
 
 #include <map>
 #include <msp/io/file.h>
-#include "except.h"
 #include "loaderaction.h"
+#include "meta.h"
 #include "parser.h"
 #include "statement.h"
 
@@ -36,21 +36,15 @@ See also classes ObjectLoader and CollectionObjectLoader in objectloader.h.
 class Loader
 {
 private:
-       struct ActionKey
-       {
-               std::string keyword;
-               std::string signature;
-
-               ActionKey(const std::string &, const std::string &);
-
-               bool operator<(const ActionKey &) const;
-       };
-
-       typedef std::map<ActionKey, LoaderAction *> ActionMap;
+       typedef std::map<StatementKey, LoaderAction *> ActionMap;
 
        ActionMap actions;
+       Parser *cur_parser;
+       unsigned cur_level;
        const Statement *cur_st;
        bool sub_loaded;
+       bool direct;
+       std::list<Loader *> aux_loaders;
 protected:
        bool check_sub_loads;
 
@@ -65,6 +59,9 @@ private:
        /** Loads data from a statement. */
        void load(const Statement &st);
 
+       /** Loads statemsnts from a parser, feeding them directly to actions. */
+       void load_direct(Parser &, unsigned);
+
        /** Processes a single statement */
        void load_statement(const Statement &st);
 
@@ -132,23 +129,73 @@ protected:
 private:
        void add(const std::string &, LoaderAction *);
 
-       LoaderAction *find_action(const ActionKey &) const;
+protected:
+       void add_auxiliary_loader(Loader &);
+
+private:
+       bool has_action(const StatementKey &) const;
+       LoaderAction *find_action(const StatementKey &) const;
 
 protected:
        /** 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;
-       }
+       const std::string &get_source() const;
+
+       /** Returns the keyword of the statement being processed.  Can be used to
+       implement dynamic keywords. */
+       const std::string &get_keyword() const;
 
        virtual void finish() { }
 };
 
 
+#if __cplusplus>=201103L
+/**
+Loads an object from a file.  The object must have a public Loader class.  Any
+extra arguments are passed to the Loader constructor.
+*/
+template<typename T, typename... Args>
+void load(T &obj, const std::string &fn, Args &... args)
+{
+       IO::BufferedFile in(fn);
+
+       Parser parser(in, fn);
+       typename T::Loader loader(obj, args...);
+       loader.load(parser);
+}
+
+/**
+Loads an object from a file stored in a collection.  The object must havea
+public Loader class.  The collection is passed to the Loader constructor,
+followed by any extra arguments.
+*/
+template<typename T, typename... Args>
+void load(T &obj, typename T::Loader::Collection &coll, const std::string &fn, Args &... args)
+{
+       RefPtr<IO::Seekable> in = coll.open_raw(fn);
+
+       Parser parser(*in, fn);
+       typename T::Loader loader(obj, coll, args...);
+       loader.load(parser);
+}
+
+/**
+Loads an object from a file stored in a collection.  The object must havea
+public Loader class.  Any extra arguments are passed to the Loader constructor.
+*/
+template<typename T, typename C, typename... Args>
+typename EnableIf<NeedsCollection<typename T::Loader>::value, void>::No load(T &obj, C &coll, const std::string &fn, Args &... args)
+{
+       RefPtr<IO::Seekable> in = coll.open_raw(fn);
+
+       Parser parser(*in, fn);
+       typename T::Loader loader(obj, args...);
+       loader.load(parser);
+}
+
+#else
+
 /**
 Loads an object from a file.  The object must have a public Loader class.
 */
@@ -162,6 +209,10 @@ void load(T &obj, const std::string &fn)
        loader.load(parser);
 }
 
+/**
+Loads an object from a file, passing one extra argument to the Loader
+constructor.  The object must have a public Loader class.
+*/
 template<typename T, typename U>
 void load(T &obj, const std::string &fn, U &arg)
 {
@@ -171,6 +222,7 @@ void load(T &obj, const std::string &fn, U &arg)
        typename T::Loader loader(obj, arg);
        loader.load(parser);
 }
+#endif
 
 } // namespace DataFile
 } // namespace Msp