text: //
  // AbstractConfiguration.h
  //
  // $Id: //poco/1.4/Util/include/Poco/Util/AbstractConfiguration.h#2 $
  //
  // Library: Util
  // Package: Configuration
  // Module:  AbstractConfiguration
  //
  // Definition of the AbstractConfiguration class.
  //
  // Copyright (c) 2004-2006, Applied Informatics Software Engineering GmbH.
  // and Contributors.
  //
  // SPDX-License-Identifier:	BSL-1.0
  //
  
  
  #ifndef Util_AbstractConfiguration_INCLUDED
  #define Util_AbstractConfiguration_INCLUDED
  
  
  #include "Poco/Util/Util.h"
  #include "Poco/Mutex.h"
  #include "Poco/RefCountedObject.h"
  #include "Poco/BasicEvent.h"
  #include <vector>
  #include <utility>
  
  
  namespace Poco {
  namespace Util {
  
  
  class Util_API AbstractConfiguration: public Poco::RefCountedObject
  	/// AbstractConfiguration is an abstract base class for different
  	/// kinds of configuration data, such as INI files, property files,
  	/// XML configuration files or the Windows Registry.
  	///
  	/// Configuration property keys have a hierarchical format, consisting
  	/// of names separated by periods. The exact interpretation of key names
  	/// is up to the actual subclass implementation of AbstractConfiguration.
  	/// Keys are case sensitive.
  	///
  	/// All public methods are synchronized, so the class is safe for multithreaded use.
  	/// AbstractConfiguration implements reference counting based garbage collection.
  	///
  	/// Subclasses must override the getRaw(), setRaw() and enumerate() methods.
  {
  public:
  	typedef std::vector<std::string> Keys;
  	
  	class KeyValue
  		/// A key-value pair, used as event argument.
  	{
  	public:
  		KeyValue(const std::string& key, std::string& value):
  			_key(key),
  			_value(value)
  		{
  		}
  		
  		const std::string& key() const
  		{
  			return _key;
  		}
  		
  		const std::string& value() const
  		{
  			return _value;
  		}
  		
  		std::string& value()
  		{
  			return _value;
  		}
  	
  	private:
  		const std::string& _key;
  		std::string& _value;
  	};
  	
  	Poco::BasicEvent<KeyValue> propertyChanging;
  		/// Fired before a property value is changed or
  		/// a new property is created.
  		///
  		/// Can be used to check or fix a property value,
  		/// or to cancel the change by throwing an exception.
  		///
  		/// The event delegate can use one of the get...() functions
  		/// to obtain the current property value.
  
  	Poco::BasicEvent<const KeyValue> propertyChanged;
  		/// Fired after a property value has been changed
  		/// or a property has been created.
  
  	Poco::BasicEvent<const std::string> propertyRemoving;
  		/// Fired before a property is removed by a
  		/// call to remove().
  		///
  		/// Note: This will even be fired if the key
  		/// does not exist and the remove operation will
  		/// fail with an exception.
  		
  	Poco::BasicEvent<const std::string> propertyRemoved;
  		/// Fired after a property has been removed by
  		/// a call to remove().
  
  	AbstractConfiguration();
  		/// Creates the AbstractConfiguration.
  
  	bool hasProperty(const std::string& key) const;
  		/// Returns true iff the property with the given key exists.
  
  	bool hasOption(const std::string& key) const;
  		/// Returns true iff the property with the given key exists.
  		///
  		/// Same as hasProperty().
  
  	bool has(const std::string& key) const;
  		/// Returns true iff the property with the given key exists.
  		///
  		/// Same as hasProperty().
  		
  	std::string getString(const std::string& key) const;
  		/// Returns the string value of the property with the given name.
  		/// Throws a NotFoundException if the key does not exist.
  		/// If the value contains references to other properties (${<property>}), these
  		/// are expanded.
  		
  	std::string getString(const std::string& key, const std::string& defaultValue) const;
  		/// If a property with the given key exists, returns the property's string value,
  		/// otherwise returns the given default value.
  		/// If the value contains references to other properties (${<property>}), these
  		/// are expanded.
  
  	std::string getRawString(const std::string& key) const;
  		/// Returns the raw string value of the property with the given name.
  		/// Throws a NotFoundException if the key does not exist.
  		/// References to other properties are not expanded.
  		
  	std::string getRawString(const std::string& key, const std::string& defaultValue) const;
  		/// If a property with the given key exists, returns the property's raw string value,
  		/// otherwise returns the given default value.
  		/// References to other properties are not expanded.
  		
  	int getInt(const std::string& key) const;
  		/// Returns the int value of the property with the given name.
  		/// Throws a NotFoundException if the key does not exist.
  		/// Throws a SyntaxException if the property can not be converted
  		/// to an int.
  		/// Numbers starting with 0x are treated as hexadecimal.
  		/// If the value contains references to other properties (${<property>}), these
  		/// are expanded.
  		
  	unsigned int getUInt(const std::string& key) const;
  		/// Returns the unsigned int value of the property with the given name.
  		/// Throws a NotFoundException if the key does not exist.
  		/// Throws a SyntaxException if the property can not be converted
  		/// to an unsigned int.
  		/// Numbers starting with 0x are treated as hexadecimal.
  		/// If the value contains references to other properties (${<property>}), these
  		/// are expanded.
  		
  	int getInt(const std::string& key, int defaultValue) const;
  		/// If a property with the given key exists, returns the property's int value,
  		/// otherwise returns the given default value.
  		/// Throws a SyntaxException if the property can not be converted
  		/// to an int.
  		/// Numbers starting with 0x are treated as hexadecimal.
  		/// If the value contains references to other properties (${<property>}), these
  		/// are expanded.
  		
  	unsigned int getUInt(const std::string& key, unsigned int defaultValue) const;
  		/// If a property with the given key exists, returns the property's unsigned int
  		/// value, otherwise returns the given default value.
  		/// Throws a SyntaxException if the property can not be converted
  		/// to an unsigned int.
  		/// Numbers starting with 0x are treated as hexadecimal.
  		/// If the value contains references to other properties (${<property>}), these
  		/// are expanded.
  
  #if defined(POCO_HAVE_INT64)
  
  	Int64 getInt64(const std::string& key) const;
  		/// Returns the Int64 value of the property with the given name.
  		/// Throws a NotFoundException if the key does not exist.
  		/// Throws a SyntaxException if the property can not be converted
  		/// to an Int64.
  		/// Numbers starting with 0x are treated as hexadecimal.
  		/// If the value contains references to other properties (${<property>}), these
  		/// are expanded.
  
  	UInt64 getUInt64(const std::string& key) const;
  		/// Returns the UInt64 value of the property with the given name.
  		/// Throws a NotFoundException if the key does not exist.
  		/// Throws a SyntaxException if the property can not be converted
  		/// to an UInt64.
  		/// Numbers starting with 0x are treated as hexadecimal.
  		/// If the value contains references to other properties (${<property>}), these
  		/// are expanded.
  
  	Int64 getInt64(const std::string& key, Int64 defaultValue) const;
  		/// If a property with the given key exists, returns the property's Int64 value,
  		/// otherwise returns the given default value.
  		/// Throws a SyntaxException if the property can not be converted
  		/// to an Int64.
  		/// Numbers starting with 0x are treated as hexadecimal.
  		/// If the value contains references to other properties (${<property>}), these
  		/// are expanded.
  
  	UInt64 getUInt64(const std::string& key, UInt64 defaultValue) const;
  		/// If a property with the given key exists, returns the property's UInt64
  		/// value, otherwise returns the given default value.
  		/// Throws a SyntaxException if the property can not be converted
  		/// to an UInt64.
  		/// Numbers starting with 0x are treated as hexadecimal.
  		/// If the value contains references to other properties (${<property>}), these
  		/// are expanded.
  
  #endif // defined(POCO_HAVE_INT64)
  
  	double getDouble(const std::string& key) const;
  		/// Returns the double value of the property with the given name.
  		/// Throws a NotFoundException if the key does not exist.
  		/// Throws a SyntaxException if the property can not be converted
  		/// to a double.
  		/// If the value contains references to other properties (${<property>}), these
  		/// are expanded.
  		
  	double getDouble(const std::string& key, double defaultValue) const;
  		/// If a property with the given key exists, returns the property's double value,
  		/// otherwise returns the given default value.
  		/// Throws a SyntaxException if the property can not be converted
  		/// to an double.
  		/// If the value contains references to other properties (${<property>}), these
  		/// are expanded.
  
  	bool getBool(const std::string& key) const;
  		/// Returns the boolean value of the property with the given name.
  		/// Throws a NotFoundException if the key does not exist.
  		/// Throws a SyntaxException if the property can not be converted
  		/// to a boolean.
  		/// If the value contains references to other properties (${<property>}), these
  		/// are expanded.
  		
  	bool getBool(const std::string& key, bool defaultValue) const;
  		/// If a property with the given key exists, returns the property's boolean value,
  		/// otherwise returns the given default value.
  		/// Throws a SyntaxException if the property can not be converted
  		/// to a boolean.
  		/// The following string values can be converted into a boolean:
  		///   - numerical values: non zero becomes true, zero becomes false
  		///   - strings: true, yes, on become true, false, no, off become false
  		/// Case does not matter.
  		/// If the value contains references to other properties (${<property>}), these
  		/// are expanded.
  		
  	virtual void setString(const std::string& key, const std::string& value);
  		/// Sets the property with the given key to the given value.
  		/// An already existing value for the key is overwritten.
  		
  	virtual void setInt(const std::string& key, int value);
  		/// Sets the property with the given key to the given value.
  		/// An already existing value for the key is overwritten.
  		
  	virtual void setUInt(const std::string& key, unsigned int value);
  		/// Sets the property with the given key to the given value.
  		/// An already existing value for the key is overwritten.
  
  #if defined(POCO_HAVE_INT64)
  
  	virtual void setInt64(const std::string& key, Int64 value);
  		/// Sets the property with the given key to the given value.
  		/// An already existing value for the key is overwritten.
  
  	virtual void setUInt64(const std::string& key, UInt64 value);
  		/// Sets the property with the given key to the given value.
  		/// An already existing value for the key is overwritten.
  
  #endif // defined(POCO_HAVE_INT64)
  
  	virtual void setDouble(const std::string& key, double value);
  		/// Sets the property with the given key to the given value.
  		/// An already existing value for the key is overwritten.
  
  	virtual void setBool(const std::string& key, bool value);
  		/// Sets the property with the given key to the given value.
  		/// An already existing value for the key is overwritten.
  		
  	void keys(Keys& range) const;
  		/// Returns in range the names of all keys at root level.
  
  	void keys(const std::string& key, Keys& range) const;
  		/// Returns in range the names of all subkeys under the given key.
  		/// If an empty key is passed, all root level keys are returned.
  	
  	const AbstractConfiguration* createView(const std::string& prefix) const;
  		/// Creates a non-mutable view (see ConfigurationView) into the configuration.
  
  	AbstractConfiguration* createView(const std::string& prefix);
  		/// Creates a view (see ConfigurationView) into the configuration.
  	
  	std::string expand(const std::string& value) const;
  		/// Replaces all occurences of ${<property>} in value with the
  		/// value of the <property>. If <property> does not exist,
  		/// nothing is changed.
  		///
  		/// If a circular property reference is detected, a
  		/// CircularReferenceException will be thrown.
  
  	void remove(const std::string& key);
  		/// Removes the property with the given key.
  		///
  		/// Does nothing if the key does not exist.
  		
  	void enableEvents(bool enable = true);
  		/// Enables (or disables) events.
  		
  	bool eventsEnabled() const;
  		/// Returns true iff events are enabled.
  	
  protected:
  	virtual bool getRaw(const std::string& key, std::string& value) const = 0;
  		/// If the property with the given key exists, stores the property's value
  		/// in value and returns true. Otherwise, returns false.
  		///
  		/// Must be overridden by subclasses.
  
  	virtual void setRaw(const std::string& key, const std::string& value) = 0;
  		/// Sets the property with the given key to the given value.
  		/// An already existing value for the key is overwritten.
  		///
  		/// Must be overridden by subclasses.
  		
  	virtual void enumerate(const std::string& key, Keys& range) const = 0;
  		/// Returns in range the names of all subkeys under the given key.
  		/// If an empty key is passed, all root level keys are returned.
  		
  	virtual void removeRaw(const std::string& key);
  		/// Removes the property with the given key.
  		///
  		/// Does nothing if the key does not exist.
  		///
  		/// Should be overridden by subclasses; the default
  		/// implementation throws a Poco::NotImplementedException.
  
  	static int parseInt(const std::string& value);
  	static unsigned parseUInt(const std::string& value);
  
  #if defined(POCO_HAVE_INT64)
  
  	static Int64 parseInt64(const std::string& value);
  	static UInt64 parseUInt64(const std::string& value);
  
  #endif // defined(POCO_HAVE_INT64)
  
  	static bool parseBool(const std::string& value);
  	void setRawWithEvent(const std::string& key, std::string value);
  	
  	virtual ~AbstractConfiguration();
  
  private:
  	std::string internalExpand(const std::string& value) const;
  	std::string uncheckedExpand(const std::string& value) const;
  
  	AbstractConfiguration(const AbstractConfiguration&);
  	AbstractConfiguration& operator = (const AbstractConfiguration&);
  
  	mutable int _depth;
  	bool        _eventsEnabled;
  	mutable Poco::Mutex _mutex;
  	
  	friend class LayeredConfiguration;
  	friend class ConfigurationView;
  	friend class ConfigurationMapper;
  };
  
  
  } } // namespace Poco::Util
  
  
  #endif // Util_AbstractConfiguration_INCLUDED
  