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Reference Guide
ws.C File Reference

Detailed Description

This program demonstrate WebSocket usage with THttpServer Custom ws.htm page is loaded and regularly sends messages to server.

#include "THttpServer.h"
#include "THttpWSHandler.h"
#include "THttpCallArg.h"
#include "TString.h"
#include "TSystem.h"
#include "TDatime.h"
#include "TTimer.h"
#include <cstdio>
class TUserHandler : public THttpWSHandler {
UInt_t fWSId{0};
Int_t fServCnt{0};
TUserHandler(const char *name = nullptr, const char *title = nullptr) : THttpWSHandler(name, title) {}
// load custom HTML page when open correspondent address
TString GetDefaultPageContent() override { return "file:ws.htm"; }
Bool_t ProcessWS(THttpCallArg *arg) override
if (!arg || (arg->GetWSId()==0)) return kTRUE;
// printf("Method %s\n", arg->GetMethod());
if (arg->IsMethod("WS_CONNECT")) {
// accept only if connection not established
return fWSId == 0;
if (arg->IsMethod("WS_READY")) {
fWSId = arg->GetWSId();
printf("Client connected %d\n", fWSId);
return kTRUE;
if (arg->IsMethod("WS_CLOSE")) {
fWSId = 0;
printf("Client disconnected\n");
return kTRUE;
if (arg->IsMethod("WS_DATA")) {
TString str;
str.Append((const char *)arg->GetPostData(), arg->GetPostDataLength());
printf("Client msg: %s\n", str.Data());
TDatime now;
SendCharStarWS(arg->GetWSId(), Form("Server replies:%s server counter:%d", now.AsString(), fServCnt++));
return kTRUE;
return kFALSE;
/// per timeout sends data portion to the client
TDatime now;
if (fWSId) SendCharStarWS(fWSId, Form("Server sends data:%s server counter:%d", now.AsString(), fServCnt++));
return kTRUE;
void ws()
THttpServer *serv = new THttpServer("http:8090");
TUserHandler *handler = new TUserHandler("name1", "title1");
serv->Register("/folder1", handler);
const char *addr = "http://localhost:8090/folder1/name1/";
printf("Starting browser with URL address %s\n", addr);
printf("In browser content of ws.htm file should be loaded\n");
printf("Please be sure that ws.htm is provided in current directory\n");
if (gSystem->InheritsFrom("TMacOSXSystem"))
gSystem->Exec(Form("open %s", addr));
else if (gSystem->InheritsFrom("TWinNTSystem"))
gSystem->Exec(Form("start %s", addr));
gSystem->Exec(Form("xdg-open %s &", addr));
// when connection will be established, data will be send to the client
TTimer *tm = new TTimer(handler, 3700);
bool Bool_t
Definition: RtypesCore.h:63
int Int_t
Definition: RtypesCore.h:45
const Bool_t kFALSE
Definition: RtypesCore.h:101
unsigned int UInt_t
Definition: RtypesCore.h:46
const Bool_t kTRUE
Definition: RtypesCore.h:100
char name[80]
Definition: TGX11.cxx:110
char * Form(const char *fmt,...)
Formats a string in a circular formatting buffer.
Definition: TString.cxx:2452
R__EXTERN TSystem * gSystem
Definition: TSystem.h:559
This class stores the date and time with a precision of one second in an unsigned 32 bit word (950130...
Definition: TDatime.h:37
const char * AsString() const
Return the date & time as a string (ctime() format).
Definition: TDatime.cxx:102
Contains arguments for single HTTP call.
Definition: THttpCallArg.h:27
UInt_t GetWSId() const
get web-socket id
Definition: THttpCallArg.h:107
const void * GetPostData() const
return pointer on posted with request data
Definition: THttpCallArg.h:140
Long_t GetPostDataLength() const
return length of posted with request data
Definition: THttpCallArg.h:143
Bool_t IsMethod(const char *name) const
returns kTRUE if post method is used
Definition: THttpCallArg.h:134
Online http server for arbitrary ROOT application.
Definition: THttpServer.h:31
Bool_t Register(const char *subfolder, TObject *obj)
Register object in subfolder.
Class for user-side handling of websocket with THttpServer.
virtual Bool_t ProcessWS(THttpCallArg *arg)=0
Int_t SendCharStarWS(UInt_t wsid, const char *str)
Send string via given websocket id.
virtual TString GetDefaultPageContent()
Provides content of default web page for registered web-socket handler Can be content of HTML page or...
virtual Bool_t HandleTimer(TTimer *timer)
Execute action in response of a timer timing out.
Definition: TObject.cxx:487
virtual Bool_t InheritsFrom(const char *classname) const
Returns kTRUE if object inherits from class "classname".
Definition: TObject.cxx:519
Basic string class.
Definition: TString.h:136
const char * Data() const
Definition: TString.h:369
TString & Append(const char *cs)
Definition: TString.h:564
virtual Int_t Exec(const char *shellcmd)
Execute a command.
Definition: TSystem.cxx:656
Handles synchronous and a-synchronous timer events.
Definition: TTimer.h:51
virtual void Start(Long_t milliSec=-1, Bool_t singleShot=kFALSE)
Starts the timer with a milliSec timeout.
Definition: TTimer.cxx:213
Sergey Linev

Definition in file ws.C.