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programmazione:crow:hello_world
Introduzione a Crow a "A Fast and Easy to use microframework for the web."
Autore: Fabio Di Matteo
Ultima revisione: 21/01/2024 - 22:03
Il seguente codice c++ imposta delle rotte che mostrano alcune caratteristiche del framework.
#include "crow.h" #include "crow/middlewares/cookie_parser.h" //#include "crow_all.h" int main() { //crow::SimpleApp app; crow::App<crow::CookieParser> app; //define your endpoint at the root directory CROW_ROUTE(app, "/")([](){ auto page = crow::mustache::load_text("index.html"); return page; }); CROW_ROUTE(app, "/ciao")([](){ auto t = crow::mustache::load_text("ciao.html"); const char* myname="Fabio Di Matteo"; auto page = crow::mustache::compile(t); crow::mustache::context ctx; ctx["name"] = myname; return page.render(ctx); }); // localhost:8080/req?p=<my value> CROW_ROUTE(app, "/req")([](const crow::request& req){ const char *page=req.url_params.get("p"); return page; }); CROW_ROUTE(app, "/cookies")([&app](const crow::request& req) { auto& ctx = app.get_context<crow::CookieParser>(req); std::string value = ctx.get_cookie("biscotto"); std::string page; if (value.empty()) { ctx.set_cookie("biscotto", "cioccolato"); page="Nessun cookie impostato."; }else{ page="Biscotto al gusto di : "+value; } return page; }); // download file (esempio: /download?f=my file.png) CROW_ROUTE(app, "/download")([](const crow::request& req,crow::response& res){ const char *f=req.url_params.get("f"); res.set_static_file_info(f); //res.set_header("Content-Disposition","filename=\"miofile.txt\""); res.end(); }); //set the port, set the app to run on multiple threads, and run the app app.port(8080).multithreaded().run(); }
makefile
all: g++ main.cc -o server
Upload di un file
Salvataggio di un file inviato attraverso un form multipart.
... CROW_ROUTE(app, "/save").methods(crow::HTTPMethod::POST)([=](const crow::request& req ){ std::string root_folder="/home/fabio/progetto"; crow::multipart::message msg(req); crow::multipart::header myheader = msg.parts[0].get_header_object("Content-Disposition"); //std::string myheader_value=myheader.value; std::string outfile_name=myheader.params["filename"]; CROW_LOG_ERROR << "File Name ->"+outfile_name; std::ofstream out_file(root_folder+"/"+outfile_name); if (!out_file) { CROW_LOG_ERROR << " Write to file failed\n"; return "Write to file failed!"; } out_file << msg.parts[0].body; out_file.close(); return "ok"; });
<!DOCTYPE html><html><head>\ <title>Piso - Upload files</title>\ <meta name=\"viewport\" content=\"width=1280, initial-scale=1\">\ </head>\ <body>\ <h2>Upload a file</h2><hr/>\ <form action=\"{{{action}}}\" method=\"post\" enctype=\"multipart/form-data\">\ <input type=\"file\" id=\"myfile\" name=\"myfile\">\ <button type=\"submit\">Upload this file</button></hr>\ </form>\ </body></html>
programmazione/crow/hello_world.txt · Ultima modifica: 27/01/2024 - 15:18 da Fabio Di Matteo
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