source/directorycollection.h

   1 #ifndef MSP_DATAFILE_DIRECTORYCOLLECTION_H_
   2 #define MSP_DATAFILE_DIRECTORYCOLLECTION_H_
   3
   4 #include <msp/fs/path.h>
   5 #include "collection.h"
   6
   7 namespace Msp {
   8 namespace DataFile {
   9
  10 /**
  11 A Collection that can automatically load items from files in a directory.
  12 */
  13 class DirectoryCollection: public Collection
  14 {
  15 private:
  16         template<typename T, bool = NeedsCollection<typename T::Loader>::value>
  17         class ItemLoader;
  18
  19         std::list<FS::Path> dirs;
  20
  21 public:
  22         DirectoryCollection();
  23
  24 protected:
  25         void set_directory(const FS::Path &);
  26         void add_directory(const FS::Path &);
  27
  28         template<typename T>
  29         CollectionItemType<T> &add_type()
  30         {
  31                 return Collection::add_type<T>().creator(&DirectoryCollection::create<T>);
  32         }
  33
  34 private:
  35         template<typename T>
  36         T *create(const std::string &name)
  37         {
  38                 FS::Path file;
  39                 if(lookup_file(name, file))
  40                 {
  41                         RefPtr<T> item = new T;
  42                         ItemLoader<T> ldr(*item, *this);
  43                         IO::BufferedFile in(file.str());
  44                         Parser parser(in, file.str());
  45                         ldr.load(parser);
  46                         return item.release();
  47                 }
  48                 else
  49                         return 0;
  50         }
  51
  52 protected:
  53         bool lookup_file(const std::string &, FS::Path &) const;
  54 };
  55
  56 template<typename T>
  57 class DirectoryCollection::ItemLoader<T, false>: public T::Loader
  58 {
  59 public:
  60         ItemLoader(T &o, Collection &):
  61                 T::Loader(o)
  62         { }
  63 };
  64
  65 template<typename T>
  66 class DirectoryCollection::ItemLoader<T, true>: public T::Loader
  67 {
  68 public:
  69         ItemLoader(T &o, Collection &c):
  70                 T::Loader(o, dynamic_cast<typename T::Loader::Collection &>(c))
  71         { }
  72 };
  73
  74 } // namespace DataFile
  75 } // namespace Msp
  76
  77 #endif