tesseract_common::ClassLoader Struct Reference

This is a wrapper around Boost DLL for loading plugins within Tesseract. More...

#include <class_loader.h>

Static Public Member Functions
template<class ClassBase >
static std::shared_ptr< ClassBase >	createSharedInstance (const std::string &symbol_name, const std::string &library_name, const std::string &library_directory="")
	Create a shared instance for the provided symbol_name loaded from the library_name searching system folders for library. More...
static bool	isClassAvailable (const std::string &symbol_name, const std::string &library_name, const std::string &library_directory="")
	Check if the symbol is available in the library_name searching system folders for library. More...
static std::vector< std::string >	getAvailableSymbols (const std::string &section, const std::string &library_name, const std::string &library_directory="")
	Get a list of available symbols under the provided section. More...
static std::vector< std::string >	getAvailableSections (const std::string &library_name, const std::string &library_directory="", bool include_hidden=false)
	Get a list of available sections. More...
static std::string	decorate (const std::string &library_name, const std::string &library_directory="")
	Give library name without prefix and suffix it will return the library name with the prefix and suffix. More...

Detailed Description

This is a wrapper around Boost DLL for loading plugins within Tesseract.

The library_name should not include the prefix 'lib' or suffix '.so'. It will add the correct prefix and suffix based on the OS.

The plugin must be exported using the macro TESSERACT_ADD_PLUGIN. In the example below, the first parameter is the derived object and the second is the assigned symbol name which is used for looding Example: TESSERACT_ADD_PLUGIN(my_namespace::MyPlugin, plugin)

auto p = ClassLoader::createSharedInstance<my_namespace::MyPluginBase>("my_plugin", "plugin");

Member Function Documentation

createSharedInstance()

template<class ClassBase >

std::shared_ptr< ClassBase > tesseract_common::ClassLoader::createSharedInstance ( const std::string &  symbol_name, const std::string &  library_name, const std::string &  library_directory = ""  )

static

Create a shared instance for the provided symbol_name loaded from the library_name searching system folders for library.

The symbol name is the alias provide when calling TESSERACT_ADD_PLUGIN

Parameters

symbol_name	The symbol to create a shared instance of
library_name	The library name to load which does not include the prefix 'lib' or suffix '.so'
library_directory	The library directory, if empty it will enable search system directories

Returns

A shared pointer of the object with the symbol name located in library_name_

decorate()

std::string tesseract_common::ClassLoader::decorate ( const std::string &  library_name, const std::string &  library_directory = ""  )

inlinestatic

Give library name without prefix and suffix it will return the library name with the prefix and suffix.

• For instance, for a library_name like "boost" it returns :
• path/to/libboost.so on posix platforms
• path/to/libboost.dylib on OSX

• path/to/boost.dll on Windows

  Todo:

  When support is dropped for 18.04 switch to using boost::dll::shared_library::decorate

  Parameters

  library_name	The library name without prefix and suffix
  library_directory	The library directory, if empty it just returns the decorated library name

  Returns

  The library name or path with prefix and suffix

getAvailableSections()

std::vector< std::string > tesseract_common::ClassLoader::getAvailableSections ( const std::string &  library_name, const std::string &  library_directory = "", bool  include_hidden = false  )

inlinestatic

Get a list of available sections.

Parameters

library_name	The library name to load which does not include the prefix 'lib' or suffix '.so'
library_directory	The library directory, if empty it will enable search system directories

Returns

A list of sections if they exist.

getAvailableSymbols()

std::vector< std::string > tesseract_common::ClassLoader::getAvailableSymbols ( const std::string &  section, const std::string &  library_name, const std::string &  library_directory = ""  )

inlinestatic

Get a list of available symbols under the provided section.

Parameters

section	The section to search for available symbols
library_name	The library name to load which does not include the prefix 'lib' or suffix '.so'
library_directory	The library directory, if empty it will enable search system directories

Returns

A list of symbols if they exist.

isClassAvailable()

bool tesseract_common::ClassLoader::isClassAvailable ( const std::string &  symbol_name, const std::string &  library_name, const std::string &  library_directory = ""  )

inlinestatic

Check if the symbol is available in the library_name searching system folders for library.

The symbol name is the alias provide when calling TESSERACT_ADD_PLUGIN

Parameters

symbol_name	The symbol to create a shared instance of
library_name	The library name to load which does not include the prefix 'lib' or suffix '.so'
library_directory	The library directory, if empty it will enable search system directories

Returns

True if the symbol exists, otherwise false

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The documentation for this struct was generated from the following files:

• tesseract_common/include/tesseract_common/class_loader.h
• tesseract_common/include/tesseract_common/class_loader.hpp