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#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, ' ');
});
// ignore all log
crow::logger::setLogLevel(crow::LogLevel::DEBUG);
//crow::logger::setHandler(std::make_shared<ExampleLogHandler>());
app.port(18080)
.multithreaded()
.run();
}
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