Dv::Props Class Reference

Storing elements in a Props object:. More...

#include <props.h>

Inheritance diagram for Dv::Props:

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Collaboration diagram for Dv::Props:

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List of all members.

Classes
class	Reference
Public Member Functions
	Props ()
	Props (std::istream &is)
std::istream &	read (std::istream &is, int n)
template<typename K >
Reference	operator[] (const K &key)
template<typename K >
const Reference	operator() (const K &key) const
bool	operator== (const Props &props)
bool	operator!= (const Props &props)
Props &	merge (const Props &source, const std::string &scope="") throw (std::logic_error)
	Load all key-value pairs from another props object under a certain scope.
Props &	select (const std::string &scope, Props &target) const
	Insert selected subkey=value pairs of this object into the target.
void	substitute (std::istream &sin, std::ostream &sout, std::string(*f)(const std::string &)=0) const throw (std::invalid_argument)
	Recursively substitute variable occurrences in sin to yield sout.
void	substitute (const std::string &sin, std::string &sout, std::string(*f)(const std::string &)=0) const throw (std::invalid_argument)
	Recursively substitute variable occurrences in sin to yield sout.
std::string	substitute (const std::string &sin, std::string(*f)(const std::string &)=0) const throw (std::invalid_argument)
	Same as above but returns result std::string.
Friends
std::istream &	operator>> (std::istream &is, Props &props)
std::ostream &	operator<< (std::ostream &is, const Props &props)
	Print a map to a stream.
Reference	operator>> (const Props &props, const std::string &key)
	Supports "reading" key values from a Props object.

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Detailed Description

Storing elements in a Props object:.

 props[key] = value;

where key and value can be of any type that can be converted to a string using Dv::tostring.

Retrieving can be done in 2 ways: using operator[]

 props[key].get<T>() // convert string to type T
 int i = props[key]; // conversion to int will be inferred
 std::cout << props[key]; // string will be printed

and using operator() which works also with 'const' props objects

 props(key) = 3 // will not compile
 props(key).get<T>() // same as above but props can be const
 int i = props(key) // same as above but props can be const
 std::cout << props(key); // string will be printed

Definition at line 33 of file props.h.

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Constructor & Destructor Documentation

Dv::Props::Props

(

)

[inline]

Definition at line 35 of file props.h.

Dv::Props::Props

(

std::istream &

is

)

[inline]

Definition at line 36 of file props.h.

References read().

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Member Function Documentation

std::istream& Dv::Props::read	(	std::istream &	is,
		int	n
	)

Referenced by Props().

template<typename K >

Reference Dv::Props::operator[]

(

const K &

key

)

[inline]

Definition at line 150 of file props.h.

References Dv::tostring().

template<typename K >

const Reference Dv::Props::operator()

(

const K &

key

)

const [inline]

Definition at line 155 of file props.h.

References Dv::tostring().

bool Dv::Props::operator==

(

const Props &

props

)

[inline]

Definition at line 159 of file props.h.

References Dv::StringMap< T >::map_.

bool Dv::Props::operator!=

(

const Props &

props

)

[inline]

Definition at line 160 of file props.h.

Props& Dv::Props::merge	(	const Props &	source,
		const std::string &	scope = ""
	)			throw (std::logic_error)

Load all key-value pairs from another props object under a certain scope.

All key-value pairs from source will be added to *this, where the key will be prefixed with scope:: if the size of scope is not zero.

Example usage:

 Props  dbconfig;
 Props  config;
 config.merge(dbconfig,"database");

If dbconfig["name"]=="admindb" then config["database::name"]=="admindb" after the merge.

Parameters:

	source	the Props object from which key=value pairs will be copied.
	scope	only key=value pairs where key starts with scope:: will be copied.

Returns:

reference to *this.

Warning:

&source must be different from this.

See also:

Dv::Props::select

Props& Dv::Props::select	(	const std::string &	scope,
		Props &	target
	)			const

Insert selected subkey=value pairs of this object into the target.

The selected pairs are those for which the key starts with the scope std::string followed by '::'. The pairs will be inserted with a key consisting of the remainder of the original key, after removing the scope std::string and '::'.

Example.

 Props  config;
 Props  dbconfig;
 config.select("database",dbconfig);

In the example, if config["database::name"] == "admindb" then dbconfig["name"] == "admindb" after the call to select.

The function returns a reference to its second first argument.

Parameters:

	target	the Props object the selected pairs will be added to.
	scope	the selected pairs have ``scope::'' as a key.

Returns:

a reference to target.

void Dv::Props::substitute	(	std::istream &	sin,
		std::ostream &	sout,
		std::string(*)(const std::string &)	f = 0
	)			const throw (std::invalid_argument)

Recursively substitute variable occurrences in sin to yield sout.

Parameters:

	sin	stream that is appended to sout.
	sout	stream that is appended to.
	f	function that transforms strings. ${name} in sin is replaced by f((*this)[name]).

Exceptions:

invalid_argument

is thrown upon a syntax error.

Sin is a stream, the contents which is appended to sout except for variable occurrences of the form ${key} or %{key} which are replaced by f((*this)[key]) and (*this)[key], respectively (the ``$'' sign can be escaped using ``\'').

Undefined (in *this) variables are replaced by the empty std::string.

Example:

 std::string query("select * from");
 props.substitute("person where name = '${name}' and age = %{age}", query, MySql::escape);

Syntax:

• Variables start with ``${'' or ``%{'' except if the ``$'' or ``'' is preceeded by a backslash (``@'').
• A backslash is a normal character, except if it is immediately followed by a ``$'' or a ``'', in which case it is not copied.

void Dv::Props::substitute	(	const std::string &	sin,
		std::string &	sout,
		std::string(*)(const std::string &)	f = 0
	)			const throw (std::invalid_argument)

Recursively substitute variable occurrences in sin to yield sout.

Parameters:

	sin	std::string that is appended to sout.
	sout	std::string that is appended to.
	f	function that transforms strings. ${name} in sin is replaced by f((*this)[name]).

Exceptions:

invalid_argument

is thrown upon a syntax error.

Sin is a std::string which is appended to sout except for variable occurrences of the form ${key} or %{key} which are replaced by f((*this)[key]) and (*this)[key], respectively (the ``$'' sign can be escaped using ``\'').

Undefined (in *this) variables are replaced by the empty std::string.

Syntax:

• Variables start with ``${'' or ``%{'' except if the ``$'' or ``'' is preceeded by a backslash (``@'').
• A backslash is a normal character, except if it is immediately followed by a ``$'' or a ``'', in which case it is not copied.

std::string Dv::Props::substitute	(	const std::string &	sin,
		std::string(*)(const std::string &)	f = 0
	)			const throw (std::invalid_argument)

Same as above but returns result std::string.

Parameters:

	sin	std::string that is appended to return value.
	f	function that transforms strings. ${name} in sin is replaced by f((*this)[name]).

Returns:

std::string with subsitutions performed.

Exceptions:

invalid_argument

is thrown upon a syntax error.

See also:

Props::substitute

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Friends And Related Function Documentation

std::istream& operator>>	(	std::istream &	is,
		Props &	props
	)			[friend]

Definition at line 38 of file props.h.

std::ostream& operator<<	(	std::ostream &	os,
		const Props &	map
	)			[friend]

Print a map to a stream.

Each line has the form

 key: value

Parameters:

	os	stream to print to
	map	to print

Returns:

os

Reimplemented from Dv::StringMap< std::string >.

Reference operator>>	(	const Props &	props,
		const std::string &	key
	)			[friend]

Supports "reading" key values from a Props object.

 Dv::Props props;
 std::string name
 int i;
 Props >> "name" >> name >> "int" >> i;

See also:

Props::Reference::operator>>

Definition at line 145 of file props.h.

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The documentation for this class was generated from the following file:

• props.h