Joining transformers to filter out emails (eg. from Outlook PST mailbox) with subject "Hello" and limit the number of mails to 10

#include "docwire.h"

 

int main(int argc, char* argv[])

{

using namespace docwire

std::filesystem::path("1.pst") | content_type::detector{} |

mail_parser{} | office_formats_parser{} |

[](Tag&& tag, const emission_callbacks& emit_tag) // Create an input from file path, parser and connect them to transformer

{

if (std::holds_alternative<tag::Mail>(tag)) // if current node is mail

{

auto subject = std::get<tag::Mail>(tag).subject // get the subject attribute

if (subject) // if subject attribute exists

{

if (subject->find("Hello") != std::string::npos) // if subject contains "Hello"

{

return continuation::skip // skip the current node

}

}

}

return emit_tag(std::move(tag))

} |

[counter = 0, max_mails = 1](Tag&& tag, const emission_callbacks& emit_tag) mutable // Create a transformer and connect it to previous transformer

{

if (std::holds_alternative<tag::Mail>(tag)) // if current node is mail

{

if (++counter > max_mails) // if counter is greater than max_mails

{

return continuation::stop // cancel the parsing process

}

}

return emit_tag(std::move(tag))

} |

PlainTextExporter() | // sets exporter to plain text

std::cout

return 0

}