#include <msp/core/maputils.h>
#include <msp/core/meta.h>
#include <msp/core/refptr.h>
+#include "collectionsource.h"
#include "loader.h"
+/* XXX This file is a big mess with too many things in it. However, the
+dependencies between those things make it difficult to split up. */
+
namespace Msp {
namespace DataFile {
/**
A collection of objects that can be loaded from a datafile. Each object is
identified by a name, which must be unique across the entire collection.
+
+While this class can be instantiated by itself and used for storing objects,
+loading requires that a subclass defines the supported types. See the add_type
+method for details.
+
+Collections can have sources for loading objects on demand. Automatic loading
+only works on a non-const Collection. See class CollectionSource for details.
*/
class Collection
{
public:
/**
- Loads objects into a Collection.
+ Loads objects into a Collection. Automatically picks up keywords from
+ defined item types.
*/
class Loader: public DataFile::Loader
{
template<typename T> friend class CollectionItemType;
private:
- template<typename T, typename S, bool = NeedsCollection<typename T::Loader>::value>
- struct Add;
-
Collection &coll;
public:
Loader(Collection &);
Collection &get_object() const { return coll; }
private:
- template<typename T, typename S, typename C>
- void coll_item(const std::string &n)
- {
- RefPtr<T> it = new T;
- load_sub(*it, dynamic_cast<C &>(coll));
- coll.add<S>(n, it.get());
- it.release();
- }
-
template<typename T, typename S>
void item(const std::string &n)
{
RefPtr<T> it = new T;
- load_sub(*it);
+ ItemLoader<T> ldr(*it, coll);
+ load_sub_with(ldr);
coll.add<S>(n, it.get());
it.release();
}
};
+protected:
+ template<typename T, bool = NeedsCollection<typename T::Loader>::value>
+ class ItemLoader;
+
private:
typedef std::map<std::string, Variant> ItemMap;
typedef std::list<CollectionItemTypeBase *> TypeList;
+ typedef std::list<CollectionSource *> SourceList;
TypeList types;
ItemMap items;
+ SourceList sources;
Collection(const Collection &);
Collection &operator=(const Collection &);
Collection() { }
virtual ~Collection();
- /**
- Adds an object into the collection. If a name collision occurs, an
- exception is thrown. The collection takes ownership of the object.
- */
+ /** Adds an object into the collection. The name must not pre-exist. The
+ collection takes ownership of the object. */
template<typename T>
void add(const std::string &name, T *item)
{
if(!item)
throw std::invalid_argument("Collection::add(item)");
- RefPtr<typename RemoveConst<T>::Type> ptr(item);
- try
- {
- insert_unique(items, name, ptr);
- }
- catch(...)
- {
- // Avoid deleting the object
- ptr.release();
- throw;
- }
+ insert_unique(items, name, RefPtr<typename RemoveConst<T>::Type>(item));
}
- /**
- Gets an object of a specific type from the collection.
- */
+ /// Gets a typed object from the collection.
template<typename T>
T &get(const std::string &name) const
{
- typedef typename RemoveConst<T>::Type NCT;
+ return extract<T>(get_item(items, name));
+ }
- return *get_item(items, name).value<RefPtr<NCT> >();
+ /** Gets a typed object from the collection. If the name is not found,
+ automatic creation with the type's creator function (if defined) or from
+ sources (if present) is attempted. */
+ template<typename T>
+ T &get(const std::string &name)
+ {
+ return extract<T>(get_var(name, get_type<T>()));
}
- /**
- Gets an object of a specific type from the collection. If the name is not
- found in the collection and there is a creator for the item type, it is
- invoked.
- */
+private:
+ const Variant &get_var(const std::string &, const CollectionItemTypeBase *);
+
template<typename T>
- T &get(const std::string &);
+ T &extract(const Variant &var) const
+ {
+ return *var.value<RefPtr<typename RemoveConst<T>::Type> >();
+ }
- /**
- Returns a list of the names of objects of a specific type in the collection.
- */
+ template<typename T>
+ void collect_items(std::list<T *> *objects, std::list<std::string> *names, std::list<std::string> *future_names) const
+ {
+ typedef RefPtr<typename RemoveConst<T>::Type> RPNCT;
+
+ for(ItemMap::const_iterator i=items.begin(); i!=items.end(); ++i)
+ if(i->second.check_type<RPNCT>())
+ {
+ if(objects)
+ objects->push_back(i->second.value<RPNCT>().get());
+ if(names)
+ names->push_back(i->first);
+ }
+
+ if(future_names)
+ if(CollectionItemTypeBase *type = get_type<T>())
+ {
+ for(SourceList::const_iterator i=sources.begin(); i!=sources.end(); ++i)
+ {
+ std::list<std::string> available_names = (*i)->get_names(*type);
+ for(std::list<std::string>::iterator j=available_names.begin(); j!=available_names.end(); ++j)
+ if(!items.count(*j))
+ future_names->push_back(*j);
+ }
+ }
+ }
+
+public:
+ /// Returns a list of the names of objects of one type in the collection.
template<typename T>
std::list<std::string> get_names() const
{
std::list<std::string> result;
- for(ItemMap::const_iterator i=items.begin(); i!=items.end(); ++i)
- if(i->second.check_type<RefPtr<typename RemoveConst<T>::Type> >())
- result.push_back(i->first);
+ collect_items<T>(0, &result, 0);
return result;
}
- /**
- Returns a list of objects of a specific type in the collection.
- */
+ /** Returns a list of the names of objects of one type in the collection or
+ available from sources. */
+ template<typename T>
+ std::list<std::string> get_names()
+ {
+ std::list<std::string> result;
+ collect_items<T>(0, &result, &result);
+ return result;
+ }
+
+ /// Returns a list of objects of one type in the collection.
template<typename T>
std::list<T *> get_list() const
{
- typedef RefPtr<typename RemoveConst<T>::Type> RPNCT;
+ std::list<T *> result;
+ collect_items<T>(&result, 0, 0);
+ return result;
+ }
+ /** Returns a list of objects of one type, loading them from sources if
+ necessary. */
+ template<typename T>
+ std::list<T *> get_list()
+ {
std::list<T *> result;
- for(ItemMap::const_iterator i=items.begin(); i!=items.end(); ++i)
- if(i->second.check_type<RPNCT>())
- result.push_back(i->second.value<RPNCT>().get());
+ std::list<std::string> future;
+ collect_items<T>(&result, 0, &future);
+ for(std::list<std::string>::iterator i=future.begin(); i!=future.end(); ++i)
+ result.push_back(&get<T>(*i));
return result;
}
- /**
- Checks whether a name exists in the collection. Does not care about the
- type of the object.
- */
- bool contains(const std::string &n) const;
+private:
+ template<typename T>
+ unsigned get_status(const std::string &name) const
+ {
+ ItemMap::const_iterator i = items.find(name);
+ if(i==items.end())
+ {
+ if(CollectionItemTypeBase *type = get_type<T>())
+ {
+ for(SourceList::const_iterator j=sources.begin(); j!=sources.end(); ++j)
+ if((*j)->is_loadable(*type, name))
+ return 2;
+ }
+ return 0;
+ }
- /**
- Returns the name of an item in the collection.
- */
+ typedef RefPtr<typename RemoveConst<T>::Type> RPNCT;
+ if(!i->second.check_type<RPNCT>())
+ return 0;
+
+ return 1;
+ }
+
+public:
+ /// Checks whether a typed object exists in the collection.
+ template<typename T>
+ bool contains(const std::string &name) const
+ { return get_status<T>(name)==1; }
+
+ /** Checks whether a typed object exists in the collection or is loadable
+ from a source. */
+ template<typename T>
+ bool contains(const std::string &name)
+ { return get_status<T>(name)>0; }
+
+ /// Returns the name of an item in the collection.
template<typename T>
const std::string &get_name(T *d) const
{
}
protected:
+ /** Adds a type to the collection. The returned descriptor object reference
+ can be used to define how objects of that type can be loaded. */
template<typename T>
CollectionItemType<T> &add_type();
-};
+ /** Returns the descriptor for a type, or null if one isn't defined. */
+ template<typename T>
+ CollectionItemTypeBase *get_type() const;
-template<typename T, typename S>
-struct Collection::Loader::Add<T, S, false>
+ void add_source(CollectionSource &);
+};
+
+template<typename T>
+class Collection::ItemLoader<T, false>: public T::Loader
{
- static void add(Loader &loader, const std::string &kwd)
- { loader.add(kwd, &Loader::item<T, S>); }
+public:
+ ItemLoader(T &o, Collection &):
+ T::Loader(o)
+ { }
};
-template<typename T, typename S>
-struct Collection::Loader::Add<T, S, true>
+template<typename T>
+class Collection::ItemLoader<T, true>: public T::Loader
{
- static void add(Loader &loader, const std::string &kwd)
- { loader.add(kwd, &Loader::coll_item<T, S, typename T::Loader::Collection>); }
+public:
+ ItemLoader(T &o, Collection &c):
+ T::Loader(o, dynamic_cast<typename T::Loader::Collection &>(c))
+ { }
};
template<typename T>
class Tag: public TagBase
- {
- public:
- virtual ~Tag() { }
- };
+ { };
std::string kwd;
+ std::vector<std::string> suffixes;
TagBase *tag;
- CollectionItemTypeBase(): tag(0) { }
+ CollectionItemTypeBase();
public:
- virtual ~CollectionItemTypeBase()
- { delete tag; }
+ virtual ~CollectionItemTypeBase();
+ void set_keyword(const std::string &);
+ const std::string &get_keyword() const { return kwd; }
+ void add_suffix(const std::string &);
+ bool match_name(const std::string &) const;
virtual void add_to_loader(Collection::Loader &) const = 0;
virtual bool can_create() const = 0;
virtual void create_item(Collection &, const std::string &) const = 0;
+ virtual void load_item(Collection &, Parser &, const std::string &) const = 0;
template<typename T>
bool check_type() const
};
+/**
+Describes a type of item that can be loaded by a Collection. These are created
+by Collection::add_type.
+*/
template<typename T>
class CollectionItemType: public CollectionItemTypeBase
{
{ coll.add(name, static_cast<S *>(obj)); }
virtual void add_to_loader(Collection::Loader &loader, const std::string &kwd)
- { Collection::Loader::Add<T, S>::add(loader, kwd); }
+ { loader.add(kwd, &Collection::Loader::item<T, S>); }
};
CreatorBase *creat;
delete store;
}
+ /** Sets a datafile keyword for this item type. The Collection's loader
+ will accept a statement with this keyword and a single string argument - the
+ item's name. */
CollectionItemType &keyword(const std::string &k)
{
- kwd = k;
+ set_keyword(k);
return *this;
}
+ /** Adds a suffix that is used to match names when looking for future
+ objects. There is no implied separator; a name matches if it ends with the
+ suffix. If a keyword is defined before any suffixes, then "."+keyword is
+ added as a suffix. */
+ CollectionItemType &suffix(const std::string &s)
+ {
+ add_suffix(s);
+ return *this;
+ }
+
+ /** Attaches a creator function to this item type. If an item is not found
+ in the Collection, the creator function for its type is called to create it.
+ The function must be a member of the Collection subclass containing the
+ type. It must return the created object, or null if it could not be
+ created. It's also permissible to load the item via other means and then
+ return null. */
template<typename C>
CollectionItemType &creator(T *(C::*func)(const std::string &))
{
return *this;
}
+ /** Specifies the storage type for items of this type. It must be a base
+ class of the actual type. */
template<typename S>
CollectionItemType &store_as()
{
if(obj)
store->store(coll, name, obj);
}
-};
-
-
-template<typename T>
-T &Collection::get(const std::string &name)
-{
- typedef typename RemoveConst<T>::Type NCT;
- if(!items.count(name))
+ virtual void load_item(Collection &coll, Parser &parser, const std::string &name) const
{
- for(TypeList::iterator i=types.begin(); i!=types.end(); ++i)
- if((*i)->can_create() && (*i)->check_type<NCT>())
- (*i)->create_item(*this, name);
+ RefPtr<T> obj = new T;
+ Collection::ItemLoader<T> ldr(*obj, coll);
+ ldr.load(parser);
+ store->store(coll, name, obj.get());
+ obj.release();
}
+};
- return *get_item(items, name).value<RefPtr<NCT> >();
-}
template<typename T>
CollectionItemType<T> &Collection::add_type()
return *type;
}
+template<typename T>
+CollectionItemTypeBase *Collection::get_type() const
+{
+ for(TypeList::const_iterator j=types.begin(); j!=types.end(); ++j)
+ if((*j)->check_type<typename RemoveConst<T>::Type>())
+ return *j;
+ return 0;
+}
+
} // namespace DataFile
} // namespace Msp
projects / libs / datafile.git / blobdiff