How to add a proto file to a Qt project

Question

I want to add this file, tutorial.proto, to my qmake Qt project, which I copied from a tutorial:

syntax="proto3";

package qtprotobuf.tutorial;

message EchoRequest {
  string message = 1;
}

message EchoResponse {
  string message = 1;
}

service EchoService {
  rpc Echo(EchoRequest) returns (EchoResponse);
}

I tried to connect the ProtoBuff library itself and everything seemed to work, at least the project is coming together.

My pro file:

QT = websockets

TARGET = server
CONFIG   += console
CONFIG   -= app_bundle
CONFIG += c++17 cmdline

TEMPLATE = app

# You can make your code fail to compile if it uses deprecated APIs.
# In order to do so, uncomment the following line.
#DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0x060000    # disables all the APIs deprecated before Qt 6.0.0

SOURCES += \
        main.cpp \
        server.cpp

# Default rules for deployment.
qnx: target.path = /tmp/$${TARGET}/bin
else: unix:!android: target.path = /opt/$${TARGET}/bin
!isEmpty(target.path): INSTALLS += target

HEADERS += \
    server.h

target.path = $$[QT_INSTALL_EXAMPLES]/websockets/echoserver
INSTALLS += target

LIBS += -lprotobuf

DISTFILES += \
    tutorial.prot

Answer 1

QT += network

TARGET = server
CONFIG += console
CONFIG -= app_bundle

TEMPLATE = app

# Path to your .proto file
PROTO_FILE = tutorial.proto

# Path to generated C++ files
PROTO_OUT_DIR = $$OUT_PWD/protobuf_generated
# Create the output directory if it doesn't exist
!exists($$PROTO_OUT_DIR) {
    system(mkdir $$PROTO_OUT_DIR)
}

# Command to generate C++ files from .proto file
PROTOC = protoc
PROTO_SRC = $$PWD/$$PROTO_FILE
PROTO_INC = -I$$PWD
PROTO_FLAGS = --cpp_out=$$PROTO_OUT_DIR $$PROTO_SRC

# Run the protoc command
system($$PROTOC $$PROTO_INC $$PROTO_FLAGS)

# Add generated files to your project
PROTO_GEN_FILES = $$files($$PROTO_OUT_DIR/*.pb.cc)
PROTO_GEN_HEADERS = $$files($$PROTO_OUT_DIR/*.pb.h)
SOURCES += $$PROTO_GEN_FILES
HEADERS += $$PROTO_GEN_HEADERS

# Include generated files in the include path
INCLUDEPATH += $$PROTO_OUT_DIR

# Add protobuf library
LIBS += -lprotobuf

This .pro file will:

• Define variables for the .proto file, output directory, protoc command, and include paths.
• Generate the C++ files from the .proto file using the protoc compiler.
• Add the generated .pb.cc and .pb.h files to your project's source and header files.
• Include the output directory in the include path.
• Link against the ProtoBuf library.