QtProtobuf

gRPC and Protobuf generator and bindings for Qt framework

see Protobuf and gRPC for more information

Linux Build

Prerequesties

Check installation of protobuf and grpc in your system. Minimum required versions are protobuf-3.6.0 and grpc-1.15.0.

Note: Older versions could be supported as well but not officially tested.

For Ubuntu

Install GRPC packages in system:

sudo apt-get install libgrpc++-dev protobuf-compiler-grpc libgrpc++1 libgrpc-dev libgrpc6

All-in-one build

If required versions of libraries are not found in your system, you may use all-in-one build procedure for prerequesties

Update submodules to fetch 3rdparty dependencies:

git submodule update --init --recursive

Build

mkdir build
cd build

#In case Qt installed in system, use:
cmake ..

#In case you have Qt installed from qt installer, use:
cmake .. -DCMAKE_PREFIX_PATH="<path/to/qt/installation>/Qt<qt_version>/<qt_version>/gcc_64/lib/cmake"

cmake --build . [--config <RELEASE|DEBUG>] -- -j<N>

Windows Build

Prerequesties

Download and install:

• Qt 5.12.3 or higher 1
• cmake-3.1 or higher 2
• Strawberry perl 5.28 3
• GoLang 1.10 or higher 4
• Yasm 1.3 or higher 5
• Actual Visual Studio Compiler with cmake support that required by Qt 6

Note: All applications should be in PATH

Update submodules to fetch 3rdparty dependencies:

git submodule update --init --recursive

Build

Open Qt MSVC command line and follow steps:

"C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\VC\Auxiliary\Build\vcvarsall.bat" x86
cd <directory with qtprotobuf project>
mkdir build
cd build
cmake ..
cmake --build . [--config <RELEASE|DEBUG>] -- /m:<N>

Note: 64-bit build is not supported yet

Usage

Direct usage of generator

protoc --plugin=protoc-gen-qtprotobuf=<path/to/bin>/qtprotobufgen --qtprotobuf_out=<output_dir> <protofile>.proto [--qtprotobuf_opt=out=<output_dir>]

Integration with project

You can integrate QtProtobuf as submodule in your project or as installed in system package. Add following line in your project CMakeLists.txt:

...
find_package(QtProtobufProject CONFIG REQUIRED COMPONENTS QtProtobuf QtGrpc)
file(GLOB PROTO_FILES ABSOLUTE ${CMAKE_CURRENT_SOURCE_DIR}/path/to/protofile1.proto
                               ${CMAKE_CURRENT_SOURCE_DIR}/path/to/protofile2.proto
                               ...
                               ${CMAKE_CURRENT_SOURCE_DIR}/path/to/protofileN.proto)
# Function below generates source files for specified PROTO_FILES,
# writes result to STATIC library target and saves its name to 
# ${QtProtobuf_GENERATED} variable
generate_qtprotobuf(TARGET MyTarget
    OUT_DIR ${CMAKE_CURRENT_BINARY_DIR}/generated
    PROTO_FILES ${PROTO_FILES})
add_executable(MyTarget main.cpp) # Add your target here
target_link_libraries(MyTarget ${QtProtobuf_GENERATED})

Optional:

You also may pre-specify expected generated headers to prevent dummy-parser mistakes

...
set(GENERATED_HEADERS
    # List of artifacts expected after qtprotobufgen job done.
    # Usually it's full list of messages in all packages with .h header suffix
    ...
    )
...
generate_qtprotobuf(TARGET MyTarget
    OUT_DIR ${CMAKE_CURRENT_BINARY_DIR}/generated
    PROTO_FILES ${PROTO_FILES}
    GENERATED_HEADERS ${GENERATED_HEADERS})
...

Usage

To enable QtProtobuf project you need to register protobuf types. It's good practice to make it in 'main' function.

...
#include <QtProtobufTypes>
...
int main(int argc, char *argv[])
{
    QtProtobuf::registerProtoTypes();
    ... //Qt application initialization and run
}

For each generated class you also need to call 'qRegisterProtobufType<GeneratedClassName>' to enable serialization and QML support

CMake functions reference

generate_qtprotobuf

generate_qtprotobuf is cmake helper function that automatically generates STATIC library target from your .proto files

Due to cmake restrictions it's required to specify resulting artifacts manually as list of header files expected after generator job finished.

Parameters:

TARGET - name of you target that will be base for generated target name

OUT_DIR - output directory that will contain generated artifacts. Usually subfolder in build directory should be used

GENERATED_HEADERS - List of header files expected after generator job finished

EXCLUDE_HEADERS - List of header files to be excluded from pre-parsed list of expected header files (e.g. nested messages that are not supported by QtProtobuf generator)

PROTO_FILES - List of .proto files that will be used in generation procedure

Outcome:

QtProtobuf_GENERATED - variable that will contain generated STATIC library target name

Usefull definitions

QTPROTOBUF_MAKE_COVERAGE - if TRUE/ON, QtProtobuf will be built with gcov intergration, to collect code coverage reports(usefull for developers). FALSE by default

QTPROTOBUF_MAKE_TESTS - if TRUE/ON, tests for QtProtobuf will be built. TRUE by default

QTPROTOBUF_MAKE_EXAMPLES - if TRUE/ON, built-in examples will be built. TRUE by default

QTPROTOBUF_EXECUTABLE - contains full path to QtProtobuf generator add_executable

Running tests

cd <build directory>
ctest

Documentation generation

Project uses doxygen for documentation generation.

For Windows additionally install:

• doxygen
• graphviz

You can generate documentation:

mkdir build
cd build
cmake ..
cmake --build . --target doc