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/*
Ousía
Copyright (C) 2014, 2015 Benjamin Paaßen, Andreas Stöckel
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/**
* @file Resource.hpp
*
* Contains the Resource class, representing an external resource as well as
* further types used for describing resources.
*
* @author Benjamin Paaßen (bpassen@techfak.uni-bielefeld.de)
*/
#ifndef _OUSIA_RESOURCE_HPP_
#define _OUSIA_RESOURCE_HPP_
#include <map>
#include <memory>
#include <string>
namespace ousia {
// Forward declaration
class ResourceLocator;
/**
* This enum contains all possible types of includable resources in Ousía.
*/
enum class ResourceType {
/**
* Unknown type.
*/
UNKNOWN,
/**
* The resource contains a domain description.
*/
DOMAIN_DESC,
/**
* The resource contains a typesystem description.
*/
TYPESYSTEM,
/**
* The resource contains a simple document.
*/
DOCUMENT,
/**
* The resource contains style attributes.
*/
ATTRIBUTES,
/**
* The resource is a stylesheet.
*/
STYLESHEET,
/**
* The resource contains script (note that the actual scripting language is
* not specified by the resource type).
*/
SCRIPT,
/**
* Generic data, such as e.g. images.
*/
DATA
};
/**
* A Location contains the location of a Resource, e.g. a file path
* on a hard drive. Note that the 'found' flag might be set to false
* indicating that a resource was not found.
*/
class Resource {
private:
/**
* Specifies whether the resource points at a valid location or not.
*/
bool valid;
/**
* Reference pointing at the location
*/
ResourceLocator const *locator;
/**
* Requested type of the resource.
*/
ResourceType type;
/**
* This is a fully qualified/canonical path to the resource found or
* in an undefined state (possibly empty) if the 'valid' flag is set
* to 'false'.
*/
std::string location;
public:
/**
* Default constructor of the Resource class, represents an invalid
* resource.
*/
Resource();
/**
* Constructor of the Resource class.
*
* @param valid specifies whether the Resource is valid or not.
* @param locator specifies the resource locator that was used to locate the
* resource.
*/
Resource(bool valid, const ResourceLocator &locator,
ResourceType type, const std::string &location);
/**
* This calls the 'stream' method of the underlying ResourceLocator that
* found this location and returns a stream containing the data of the
* Resource at this location.
*
* @return a stream containing the data of the Resource at this
* location. This has to be a unique_pointer because the current
* C++11 compiler does not yet support move semantics for
* streams.
*/
std::unique_ptr<std::istream> stream() const;
/**
* Returns whether this resource is valid or not.
*
* @return true if the resource is valid, false otherwise.
*/
bool isValid() const { return valid; }
/**
* Returns a reference pointing at the locator that was used to locate this
* resource.
*
* @return the locator used for locating this resource.
*/
const ResourceLocator &getLocator() const { return *locator; }
/**
* Returns the type of the resource that was requested when the resource was
* located.
*
* @return the type of the resource.
*/
ResourceType getType() const { return type; }
/**
* Returns a canonical location that can be used in a hash map to identify
* a resource.
*/
const std::string &getLocation() const { return location; }
};
/**
* Invalid resource instance.
*/
extern const Resource NullResource;
}
#endif /* _OUSIA_RESOURCE_HPP_ */
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