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Diffstat (limited to 'lib/crow/examples/example.cpp')
| -rw-r--r-- | lib/crow/examples/example.cpp | 173 |
1 files changed, 173 insertions, 0 deletions
diff --git a/lib/crow/examples/example.cpp b/lib/crow/examples/example.cpp new file mode 100644 index 0000000..1355b03 --- /dev/null +++ b/lib/crow/examples/example.cpp @@ -0,0 +1,173 @@ +#include "crow.h" + +#include <sstream> + +class ExampleLogHandler : public crow::ILogHandler { + public: + void log(std::string /*message*/, crow::LogLevel /*level*/) override { +// cerr << "ExampleLogHandler -> " << message; + } +}; + +struct ExampleMiddleware +{ + std::string message; + + ExampleMiddleware() + { + message = "foo"; + } + + void setMessage(std::string newMsg) + { + message = newMsg; + } + + struct context + { + }; + + void before_handle(crow::request& /*req*/, crow::response& /*res*/, context& /*ctx*/) + { + CROW_LOG_DEBUG << " - MESSAGE: " << message; + } + + void after_handle(crow::request& /*req*/, crow::response& /*res*/, context& /*ctx*/) + { + // no-op + } +}; + +int main() +{ + crow::App<ExampleMiddleware> app; + + app.get_middleware<ExampleMiddleware>().setMessage("hello"); + + CROW_ROUTE(app, "/") + .name("hello") + ([]{ + return "Hello World!"; + }); + + CROW_ROUTE(app, "/about") + ([](){ + return "About Crow example."; + }); + + // a request to /path should be forwarded to /path/ + CROW_ROUTE(app, "/path/") + ([](){ + return "Trailing slash test case.."; + }); + + + // simple json response + // To see it in action enter {ip}:18080/json + CROW_ROUTE(app, "/json") + ([]{ + crow::json::wvalue x; + x["message"] = "Hello, World!"; + return x; + }); + + // To see it in action enter {ip}:18080/hello/{integer_between -2^32 and 100} and you should receive + // {integer_between -2^31 and 100} bottles of beer! + CROW_ROUTE(app,"/hello/<int>") + ([](int count){ + if (count > 100) + return crow::response(400); + std::ostringstream os; + os << count << " bottles of beer!"; + return crow::response(os.str()); + }); + + // To see it in action submit {ip}:18080/add/1/2 and you should receive 3 (exciting, isn't it) + CROW_ROUTE(app,"/add/<int>/<int>") + ([](const crow::request& /*req*/, crow::response& res, int a, int b){ + std::ostringstream os; + os << a+b; + res.write(os.str()); + res.end(); + }); + + // Compile error with message "Handler type is mismatched with URL paramters" + //CROW_ROUTE(app,"/another/<int>") + //([](int a, int b){ + //return crow::response(500); + //}); + + // more json example + + // To see it in action, I recommend to use the Postman Chrome extension: + // * Set the address to {ip}:18080/add_json + // * Set the method to post + // * Select 'raw' and then JSON + // * Add {"a": 1, "b": 1} + // * Send and you should receive 2 + + // A simpler way for json example: + // * curl -d '{"a":1,"b":2}' {ip}:18080/add_json + CROW_ROUTE(app, "/add_json") + .methods("POST"_method) + ([](const crow::request& req){ + auto x = crow::json::load(req.body); + if (!x) + return crow::response(400); + int sum = x["a"].i()+x["b"].i(); + std::ostringstream os; + os << sum; + return crow::response{os.str()}; + }); + + // Example of a request taking URL parameters + // If you want to activate all the functions just query + // {ip}:18080/params?foo='blabla'&pew=32&count[]=a&count[]=b + CROW_ROUTE(app, "/params") + ([](const crow::request& req){ + std::ostringstream os; + + // To get a simple string from the url params + // To see it in action /params?foo='blabla' + os << "Params: " << req.url_params << "\n\n"; + os << "The key 'foo' was " << (req.url_params.get("foo") == nullptr ? "not " : "") << "found.\n"; + + // To get a double from the request + // To see in action submit something like '/params?pew=42' + if(req.url_params.get("pew") != nullptr) { + double countD = boost::lexical_cast<double>(req.url_params.get("pew")); + os << "The value of 'pew' is " << countD << '\n'; + } + + // To get a list from the request + // You have to submit something like '/params?count[]=a&count[]=b' to have a list with two values (a and b) + auto count = req.url_params.get_list("count"); + os << "The key 'count' contains " << count.size() << " value(s).\n"; + for(const auto& countVal : count) { + os << " - " << countVal << '\n'; + } + + // To get a dictionary from the request + // You have to submit something like '/params?mydict[a]=b&mydict[abcd]=42' to have a list of pairs ((a, b) and (abcd, 42)) + auto mydict = req.url_params.get_dict("mydict"); + os << "The key 'dict' contains " << mydict.size() << " value(s).\n"; + for(const auto& mydictVal : mydict) { + os << " - " << mydictVal.first << " -> " << mydictVal.second << '\n'; + } + + return crow::response{os.str()}; + }); + + CROW_ROUTE(app, "/large") + ([]{ + return std::string(512*1024, ' '); + }); + + // enables all log + app.loglevel(crow::LogLevel::DEBUG); + //crow::logger::setHandler(std::make_shared<ExampleLogHandler>()); + + app.port(18080) + .multithreaded() + .run(); +} |
