seqan3::output_file_validator Class Reference

A validator that checks if a given path is a valid output file. More...

#include <seqan3/argument_parser/validators.hpp>

Inheritance diagram for seqan3::output_file_validator:

Public Types
using	value_type = std::string
	Type of values that are tested by validator.

Public Member Functions
std::string	get_help_page_message () const
	Returns a message that can be appended to the (positional) options help page info.
template<std::ranges::ForwardRange range_type>
void	operator() (range_type const &v) const
	Tests whether every path in list v passes validation. See operator()(value_type const & value) for further information. More...
virtual void	operator() (std::filesystem::path const &file) const override
	Tests whether path is does not already exists and is writable. More...
Constructors, destructor and assignment
	output_file_validator ()=default
	Defaulted.
	output_file_validator (output_file_validator const &)=default
	Defaulted.
	output_file_validator (output_file_validator &&)=default
	Defaulted.
output_file_validator &	operator= (output_file_validator const &)=default
	Defaulted.
output_file_validator &	operator= (output_file_validator &&)=default
	Defaulted.
virtual	~output_file_validator ()=default
	Virtual Destructor.
	file_validator_base ()=default
	Defaulted.
	file_validator_base (file_validator_base const &)=default
	Defaulted.
	file_validator_base (file_validator_base &&)=default
	Defaulted.
	file_validator_base (std::vector< std::string > extensions)
	Constructs from a set of valid extensions. More...

Protected Member Functions
void	validate_filename (std::filesystem::path const &path) const
	Validates the given filename path based on the specified extensions. More...
void	validate_readability (std::filesystem::path const &path) const
	Checks if the given path is readable. More...
void	validate_writeability (std::filesystem::path const &path) const
	Checks if the given path is writable. More...

Protected Attributes
std::vector< std::string >	extensions {}
	Stores the extensions.

Related Functions
(Note that these are not member functions.)
Requirements for seqan3::Validator
You can expect these (meta-)functions on all types that implement seqan3::Validator.
void	operator() (value_type const &cmp) const
	Validates the value 'cmp' and throws a seqan3::validation_failed on failure. More...

Detailed Description

A validator that checks if a given path is a valid output file.

On construction, the validator can receive a list (std::vector over std::string) of valid file extensions. The struct acts as a functor that throws a seqan3::parser_invalid_argument exception whenever a given filename's extension (sts::string) is not in the given list of valid file extensions, if the file already exist, or if the parent path does not have the proper writer permissions.

#include <seqan3/argument_parser/all.hpp>
#include <seqan3/core/debug_stream.hpp>
#include <seqan3/std/filesystem>

int main(int argc, const char ** argv)
{
    seqan3::argument_parser myparser{"Test", argc, argv}; // initialize

    std::filesystem::path myfile{};

    myparser.add_option(myfile,'f',"file","Output file containing the processed sequences.",
                        seqan3::option_spec::DEFAULT, seqan3::output_file_validator{{"fa","fasta"}});

    // an exception will be thrown if the user specifies a filename
    // that does not have one of the extensions ["fa","fasta"],
    // if the file already exists, or if the file is not writable.
    try
    {
        myparser.parse();
    }
    catch (seqan3::parser_invalid_argument const & ext) // the user did something wrong
    {
        std::cerr << "[PARSER ERROR] " << ext.what() << "\n"; // customize your error message
        return -1;
    }

    seqan3::debug_stream << "filename given by user passed validation: " << myfile << "\n";
    return 0;
}

Note

The validator works on every type that can be implicitly converted to std::filesystem::path.

Member Function Documentation

file_validator_base()

seqan3::file_validator_base::file_validator_base

inlineexplicit

Constructs from a set of valid extensions.

Parameters

[in]

extensions

The valid extensions to validate for.

operator()() [1/2]

template<std::ranges::ForwardRange range_type>

void seqan3::file_validator_base::operator() ( range_type const &  v ) const

inlineinherited

Tests whether every path in list v passes validation. See operator()(value_type const & value) for further information.

Template Parameters

range_type

The type of range to check; must model std::ranges::ForwardRange and the value type must be convertible to std::filesystem::path.

Parameters

v	The input range to iterate over and check every element.

Exceptions

parser_invalid_argument

operator()() [2/2]

virtual void seqan3::output_file_validator::operator() ( std::filesystem::path const &  file ) const

inlineoverridevirtual

Tests whether path is does not already exists and is writable.

Parameters

file	The input value to check.

Exceptions

parser_invalid_argument

if the validation process failed. Might be nested with std::filesystem::filesystem_error on unhandled OS API errors.

Implements seqan3::file_validator_base.

validate_filename()

void seqan3::file_validator_base::validate_filename ( std::filesystem::path const &  path ) const

inlineprotectedinherited

Validates the given filename path based on the specified extensions.

Parameters

path	The filename path.

Exceptions

parser_invalid_argument

if the specified extensions don't match the given path, or std::filesystem::filesystem_error on underlying OS API errors.

validate_readability()

void seqan3::file_validator_base::validate_readability ( std::filesystem::path const &  path ) const

inlineprotectedinherited

Checks if the given path is readable.

Parameters

path	The path to check.

Returns

true if readable, otherwise false.

Exceptions

seqan3::parser_invalid_argument

if the path is not readable, or std::filesystem::filesystem_error on underlying OS API errors.

validate_writeability()

void seqan3::file_validator_base::validate_writeability ( std::filesystem::path const &  path ) const

inlineprotectedinherited

Checks if the given path is writable.

Parameters

path	The path to check.

Returns

true if writable, otherwise false.

Exceptions

seqan3::parser_invalid_argument

if the file could not be opened for writing, or std::filesystem::filesystem_error on underlying OS API errors.

Friends And Related Function Documentation

operator()()

void operator() ( value_type const &  cmp ) const

related

Validates the value 'cmp' and throws a seqan3::validation_failed on failure.

Template Parameters

value_type

The type of the value to be validated.

Parameters

[in,out]

cmp

The value to be validated.

Exceptions

seqan3::validation_failed

if value 'cmp' does not pass validation.

Attention

This is a concept requirement, not an actual function (however types satisfying this concept will provide an implementation).

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

• seqan3/argument_parser/validators.hpp