Botfather

With Botfather one can write crossplatform bots for Android, Desktop and Web (browser) applications in JavaScript. For this purpose Botfather provides several JavaScript APIs featuring image matching and more. Furthermore scripts can be turned into crossplatform binaries using the Botfather Binary Generator Tool (bingen for short).

Building on Linux

1. Install gcc and cmake (e.g. sudo pacman -S gcc cmake)
2. Install Qt5, including the Qt5Script module (e.g. sudo pacman -S qt5)
3. Install libgit2 (e.g. sudo pacman -S libgit2)
4. Install opencv (e.g. sudo pacman -S opencv)
5. Download the CEF binary distribution and point CEF_ROOT to it
   1. wget https://cef-builds.spotifycdn.com/cef_binary_3.3578.1861.g1992780_linux64.tar.bz2
   2. tar -xvf cef_binary_3.3578.1861.g1992780_linux64.tar.bz2
   3. export CEF_ROOT=$(pwd)/cef_binary_3.3578.1861.g1992780_linux64
6. Clone the repository and enter the directory
7. Build the project
   1. mkdir build && cd build
   2. cmake -DCMAKE_BUILD_TYPE=Release ..
   3. make

Building a Flatpak

We use these builds for testing Flatpak runtimes and to pre-build the binaries we later ship to Flathub.

1. Install the runtime and matching SDK: flatpak install flathub org.kde.Platform//5.15-23.08 org.kde.Sdk//5.15-23.08
2. Build the app and put it in a repository: flatpak-builder --repo=flatpak/repo --force-clean flatpak/build-dir flatpak/io.botfather.Nightly.yaml
3. Install and run the app for testing:
   1. flatpak --user install ./flatpak/repo io.botfather.Nightly
   2. flatpak run io.botfather.Nightly

Building on Windows

1. Install Visual Studio including the Desktop development with C++ option
2. Install CMake
3. Install Qt 5.15.2
   • Enable the Archive version filter to list Qt 5 releases
   • Make sure to install the Qt Script module
   • Add C:\Qt\5.15.2\msvc2015_64 to the CMAKE_PREFIX_PATH environment variable
4. Set up Chromium Embedded Framework (CEF)
   1. Download https://cef-builds.spotifycdn.com/cef_binary_3.3578.1861.g1992780_windows64.tar.bz2
   2. Extract the archive to a persistent location
   3. Set the CEF_ROOT environment variable to the extracted directory
5. Set up OpenCV 4
   1. Download and run the OpenCV installer for Windows
   2. Select the OpenCV directory and a build directory in CMake
   3. Configure and make sure opencv_world is selected
   4. Generate and open the project
   5. Build ALL_BUILD in the Release configuration
   6. Point the OPENCV_ROOT environment variable to the build directory
6. Set up libgit2
   1. Download and extract the latest libgit2 release
   2. Select the libgit2 directory and a build directory in CMake
   3. Configure, generate, and open the project
   4. Build ALL_BUILD in the Release configuration
   5. Add the libgit2 source and build/Release directories to the CMAKE_PREFIX_PATH environment variable
7. Build Botfather
   1. Clone the botfather repository
   2. Select the botfather directory and a build directory in CMake
   3. Configure, generate, and open the project
   4. Build ALL_BUILD in the Release configuration
   5. Copy git2.dll and opencv_world4xxx.dll to the build/bin/Release directory

VSCode Setup

1. Install the C/C++ VSCode Extension

2. Update the extension's IntelliSense configuration

   1. Open the Command Palette (Ctrl+Shift+P)

   2. Search for >C/C++: Edit Configurations (UI)

   3. Add third-party dependencies to the Include path section

      On Arch Linux, the following should be sufficient:

      ${workspaceFolder}/**
      /usr/include/qt/**
      /usr/include/opencv4/**
      /path/to/cef_binary_3.3578.1861.g1992780_linux64/**
      

      On Ubuntu, the paths differ slightly:

      ${workspaceFolder}/**
      /usr/include/x86_64-linux-gnu/qt5/**
      /usr/include/x86_64-linux-gnu/opencv4/**
      /path/to/cef_binary_3.3578.1861.g1992780_linux64/**
      

      On Windows, something like this should work:

      ${workspaceFolder}/**
      C:\Qt\5.15.2\msvc2015_64\include\**
      C:\LIBGIT2\libgit2-1.8.2\include\**
      C:\OPENCV\4.10.0\build\include\**
      C:\CEF\cef_binary_3.3578.1861.g1992780_windows64\**
      

Troubleshooting

LaunchProcess: failed to execvp: ./webhelper

This means there's no webhelper binary next to the botfather binary. Fix this problem by placing a webhelper binary next to the botfather binary matching the platform and build type.

Browser is blank / nothing works after CEF Update

Rebuild the both webhelper and botfather.

How to choose a new CEF version

Look up the latest supported CEF Release Branches and attempt to use it. In case the version appears unstable, use the release CefSharp is based on.

Debugging the Flatpak

Add the following build options to the io.botfather.Nightly.yaml to prevent the builder from stipping debug symbols from the build.

"build-options": {
	"no-debuginfo": true,
	"strip": false
}

Then start a shell in the sandbox using flatpak-builder --run <build-dir> <manifest> sh. Now use gdb, strace, ldd and so on to debug.

More infos can be found in the Flatpak documentation on debugging.