dds::topic::Filter Class Reference

Filter objects contain SQL expressions that allow the application to specify a filter on the locally available data. More...

#include "Filter.hpp"

Inherits dds::core::Value< D >.

Public Types
typedef D::const_iterator	const_iterator
typedef D::iterator	iterator

Public Member Functions
	Filter (const std::string &query_expression)
template<typename FWIterator >
	Filter (const std::string &query_expression, const FWIterator &params_begin, const FWIterator &params_end)
	Filter (const std::string &query_expression, const std::vector< std::string > &params)
void	add_parameter (const std::string &param)
iterator	begin ()
const_iterator	begin () const
iterator	end ()
const_iterator	end () const
const std::string &	expression () const
bool	operator!= (const Value &other) const
D *	operator-> ()
const D *	operator-> () const
bool	operator== (const Value &other) const
template<typename FWIterator >
void	parameters (const FWIterator &begin, const FWIterator end)
uint32_t	parameters_length () const

Detailed Description

Filter objects contain SQL expressions that allow the application to specify a filter on the locally available data.

A Filter is used to create a ContentFilteredTopic.

SQL Expression

The SQL query string is set by expression which must be a subset of the SQL query language. In this query expression, parameters may be used, which must be set in the sequence of strings defined by the parameter query_parameters. A parameter is a string which can define an integer, float, string or enumeration. The number of values in query_parameters must be equal or greater than the highest referenced n token in the query_expression (e.g. if %1 and %8 are used as parameters in the query_expression, the query_parameters should at least contain n+1 = 9 values).
Look here for the specific query expression syntax.

See also

dds::topic::ContentFilteredTopic

Topic Definition

Definition at line 57 of file Filter.hpp.

Member Typedef Documentation

const_iterator

typedef D::const_iterator dds::topic::Filter::const_iterator

Iterator for the query expression parameters.

Definition at line 68 of file Filter.hpp.

iterator

typedef D::iterator dds::topic::Filter::iterator

Iterator for the query expression parameters.

Definition at line 63 of file Filter.hpp.

Constructor & Destructor Documentation

Filter() [1/3]

dds::topic::Filter::Filter

(

const std::string &

query_expression

)

Create a Filter based on a query expression.

Parameters

query_expression

SQL expression

Exceptions

dds::core::Exception

Filter() [2/3]

template<typename FWIterator >

dds::topic::Filter::Filter	(	const std::string &	query_expression,
		const FWIterator &	params_begin,
		const FWIterator &	params_end
	)

Create a Filter based on a query expression and an iterable parameter container.

Parameters

query_expression

SQL expression

Template Parameters

params_begin	Iterator pointing to the beginning of the parameters to set
params_end	Iterator pointing to the end of the parameters to set

Exceptions

dds::core::Exception

Filter() [3/3]

dds::topic::Filter::Filter	(	const std::string &	query_expression,
		const std::vector< std::string > &	params
	)

Create a Filter based on a query expression and parameter vector.

Parameters

query_expression

SQL expression

Template Parameters

params

Vector containing SQL expression parameters

Exceptions

dds::core::Exception

Member Function Documentation

add_parameter()

void dds::topic::Filter::add_parameter

(

const std::string &

param

)

Adds a parameter to the query.

See SQL expression info

Parameters

param

The parameter to add

Exceptions

dds::core::Exception

begin() [1/2]

iterator dds::topic::Filter::begin

(

)

Provides the begin iterator to the SQL expression parameter list.

See SQL expression info

Returns

dds::topic::Filter::iterator The begin iterator

Exceptions

dds::core::Exception

begin() [2/2]

const_iterator dds::topic::Filter::begin

(

)

const

Provides the begin iterator to the SQL expression parameter list.

See SQL expression info

Returns

dds::topic::Filter::const_iterator The begin iterator

Exceptions

dds::core::Exception

end() [1/2]

iterator dds::topic::Filter::end

(

)

The end iterator to the SQL expression parameter list.

See SQL expression info

Returns

dds::topic::Filter::iterator The end iterator

Exceptions

dds::core::Exception

end() [2/2]

const_iterator dds::topic::Filter::end

(

)

const

The end iterator to the SQL expression parameter list.

See SQL expression info

Returns

dds::topic::Filter::const_iterator The end iterator

Exceptions

dds::core::Exception

expression()

const std::string& dds::topic::Filter::expression

(

)

const

Get the query expression.

Returns

std::string The SQL expression.

Exceptions

dds::core::Exception

operator!=()

template<typename D >

bool dds::core::Value< D >::operator!= ( const Value< D > &  other ) const

inherited

Compare this Value with another Value

Parameters

other

Value

Returns

true if not equal

operator->() [1/2]

template<typename D >

D* dds::core::Value< D >::operator-> ( )

inherited

The operator->() is provided to be able to directly invoke functions on the delegate.

The decision to provide direct access to the delegate was motivated by the need for providing a way that was not invasive with respect to the CXXDDS API and yet would allow for vendor-specific extension. Thus vendor-specific extensions can be invoked on the Value and on all its subclasses as follows:

my_dds_value.standard_function();
my_dds_value->vendor_specific_extension();

Returns

a reference to delegate.

operator->() [2/2]

template<typename D >

const D* dds::core::Value< D >::operator-> ( ) const

inherited

The operator->() is provided to be able to directly invoke functions on the delegate.

The decision to provide direct access to the delegate was motivated by the need for providing a way that was not invasive with respect to the CXXDDS API and yet would allow for vendor-specific extension. Thus vendor-specific extensions can be invoked on the Value and on all its subclasses as follows:

my_dds_value.standard_function();
my_dds_value->vendor_specific_extension();

Returns

a reference to delegate.

operator==()

template<typename D >

bool dds::core::Value< D >::operator== ( const Value< D > &  other ) const

inherited

Compare this Value with another Value

Parameters

other

Value

Returns

true if equal

parameters()

template<typename FWIterator >

void dds::topic::Filter::parameters	(	const FWIterator &	begin,
		const FWIterator	end
	)

Sets the query parameters.

See SQL expression info

Template Parameters

begin	Iterator pointing to the beginning of the parameters to set
end	Iterator pointing to the end of the parameters to set

Exceptions

dds::core::Exception

parameters_length()

uint32_t dds::topic::Filter::parameters_length

(

)

const

Gets the number of parameters in the query of the filter.

See SQL expression info

Returns

uint32_t The number of parameters in the query

Exceptions

dds::core::Exception

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

• dds/topic/Filter.hpp