Qt for WebAssembly

Thanks for the update. When can we expect this merged? Also why was QNetworkRequest::DefaultTransferTimeoutConstant used for default value? In the documentation https://doc.qt.io/qt-5/qnetworkrequest.html#setTransferTimeout if the function was never called the actual default value is stated to be 0 which is equal to no time limit. DefaultTransferTimeoutConstant is just used as default value if the function was called without any arguments.

@lorn-potter Thank you.I use OpenAL and it works for me.

QtCreator does not have full support for using emscripten, unless you use Qt 5.15. Even then it is still experimental and you need to enable the WebAssembly plugin from within QtCreator first. It's just easier to build using the commandline.

Short answer... you can't get the full file path of a file. Your question is more related to safety/security standards regarding major browsers and the decisions related to them made by owner companies/foundations. That is, javascript is not allowed to know the full path of a file shared by the user. So, fileContentReady or in general any webassembly function will end up being a javascript function, limited to the security standards imposed on js implementation by the browser. (You can always ask the user to install a java applet :P )

@lorn-potter I have installed emsdk using ./emsdk install sdk-fastcomp-1.38.27-64bit ./emsdk activate sdk-fastcomp-1.38.27-64bit bcz installation fails(Error : No such tool/sdk) with ./emsdk install sdk-1.38.16-64bit and using online installer as well as offline static build am getting same error for simple Qt Application build error log kmb@ubuntu:~/Work/FEB2020/TestApp/build$ /home/kmb/Qt/5.14.0/wasm_32/bin/qmake .. Info: creating stash file /home/kmb/Work/FEB2020/TestApp/build/.qmake.stash kmb@ubuntu:~/Work/FEB2020/TestApp/build$ make em++ -c -pipe -O3 -std=gnu++11 -s ALLOW_MEMORY_GROWTH=1 -Wall -Wextra -DQT_DEPRECATED_WARNINGS -DQT_NO_DEBUG -DQT_QUICK_LIB -DQT_GUI_LIB -DQT_QMLMODELS_LIB -DQT_QML_LIB -DQT_NETWORK_LIB -DQT_CORE_LIB -I../../TestApp -I. -I../../../../Qt/5.14.0/wasm_32/include -I../../../../Qt/5.14.0/wasm_32/include/QtQuick -I../../../../Qt/5.14.0/wasm_32/include/QtGui -I../../../../Qt/5.14.0/wasm_32/include/QtQmlModels -I../../../../Qt/5.14.0/wasm_32/include/QtQml -I../../../../Qt/5.14.0/wasm_32/include/QtNetwork -I../../../../Qt/5.14.0/wasm_32/include/QtCore -I. -I/home/kmb/.emscripten_ports/openssl/include -I../../../../Qt/5.14.0/wasm_32/mkspecs/wasm-emscripten -o main.o ../main.cpp em++ -c -pipe -O3 -std=gnu++11 -s ALLOW_MEMORY_GROWTH=1 -Wall -Wextra -DQT_DEPRECATED_WARNINGS -DQT_NO_DEBUG -DQT_QUICK_LIB -DQT_GUI_LIB -DQT_QMLMODELS_LIB -DQT_QML_LIB -DQT_NETWORK_LIB -DQT_CORE_LIB -I../../TestApp -I. -I../../../../Qt/5.14.0/wasm_32/include -I../../../../Qt/5.14.0/wasm_32/include/QtQuick -I../../../../Qt/5.14.0/wasm_32/include/QtGui -I../../../../Qt/5.14.0/wasm_32/include/QtQmlModels -I../../../../Qt/5.14.0/wasm_32/include/QtQml -I../../../../Qt/5.14.0/wasm_32/include/QtNetwork -I../../../../Qt/5.14.0/wasm_32/include/QtCore -I. -I/home/kmb/.emscripten_ports/openssl/include -I../../../../Qt/5.14.0/wasm_32/mkspecs/wasm-emscripten -o testapp.js_plugin_import.o /home/kmb/Work/FEB2020/TestApp/build/testapp.js_plugin_import.cpp em++ -c -pipe -O3 -std=gnu++11 -s ALLOW_MEMORY_GROWTH=1 -Wall -Wextra -DQT_DEPRECATED_WARNINGS -DQT_NO_DEBUG -DQT_QUICK_LIB -DQT_GUI_LIB -DQT_QMLMODELS_LIB -DQT_QML_LIB -DQT_NETWORK_LIB -DQT_CORE_LIB -I../../TestApp -I. -I../../../../Qt/5.14.0/wasm_32/include -I../../../../Qt/5.14.0/wasm_32/include/QtQuick -I../../../../Qt/5.14.0/wasm_32/include/QtGui -I../../../../Qt/5.14.0/wasm_32/include/QtQmlModels -I../../../../Qt/5.14.0/wasm_32/include/QtQml -I../../../../Qt/5.14.0/wasm_32/include/QtNetwork -I../../../../Qt/5.14.0/wasm_32/include/QtCore -I. -I/home/kmb/.emscripten_ports/openssl/include -I../../../../Qt/5.14.0/wasm_32/mkspecs/wasm-emscripten -o testapp.js_qml_plugin_import.o /home/kmb/Work/FEB2020/TestApp/build/testapp.js_qml_plugin_import.cpp /home/kmb/Qt/5.14.0/wasm_32/bin/rcc -name qml ../qml.qrc -o qrc_qml.cpp em++ -c -pipe -O3 -std=gnu++11 -s ALLOW_MEMORY_GROWTH=1 -Wall -Wextra -DQT_DEPRECATED_WARNINGS -DQT_NO_DEBUG -DQT_QUICK_LIB -DQT_GUI_LIB -DQT_QMLMODELS_LIB -DQT_QML_LIB -DQT_NETWORK_LIB -DQT_CORE_LIB -I../../TestApp -I. -I../../../../Qt/5.14.0/wasm_32/include -I../../../../Qt/5.14.0/wasm_32/include/QtQuick -I../../../../Qt/5.14.0/wasm_32/include/QtGui -I../../../../Qt/5.14.0/wasm_32/include/QtQmlModels -I../../../../Qt/5.14.0/wasm_32/include/QtQml -I../../../../Qt/5.14.0/wasm_32/include/QtNetwork -I../../../../Qt/5.14.0/wasm_32/include/QtCore -I. -I/home/kmb/.emscripten_ports/openssl/include -I../../../../Qt/5.14.0/wasm_32/mkspecs/wasm-emscripten -o qrc_qml.o qrc_qml.cpp sed -e s/@APPNAME@/TestApp/g /home/kmb/Qt/5.14.0/wasm_32/plugins/platforms/wasm_shell.html > /home/kmb/Work/FEB2020/TestApp/build/TestApp.html cp -f /home/kmb/Qt/5.14.0/wasm_32/plugins/platforms/qtloader.js /home/kmb/Work/FEB2020/TestApp/build cp -f /home/kmb/Qt/5.14.0/wasm_32/plugins/platforms/qtlogo.svg /home/kmb/Work/FEB2020/TestApp/build em++ -s WASM=1 -s FULL_ES2=1 -s USE_WEBGL2=1 -s NO_EXIT_RUNTIME=0 -s ERROR_ON_UNDEFINED_SYMBOLS=1 --bind -O3 -s ALLOW_MEMORY_GROWTH=1 -o ./TestApp.js main.o testapp.js_plugin_import.o testapp.js_qml_plugin_import.o qrc_qml.o /home/kmb/Qt/5.14.0/wasm_32/plugins/platforms/libqwasm.a /home/kmb/Qt/5.14.0/wasm_32/lib/libQt5EventDispatcherSupport.a /home/kmb/Qt/5.14.0/wasm_32/lib/libQt5FontDatabaseSupport.a /home/kmb/Qt/5.14.0/wasm_32/lib/libqtfreetype.a /home/kmb/Qt/5.14.0/wasm_32/lib/libQt5EglSupport.a /home/kmb/Qt/5.14.0/wasm_32/plugins/imageformats/libqgif.a /home/kmb/Qt/5.14.0/wasm_32/plugins/imageformats/libqicns.a /home/kmb/Qt/5.14.0/wasm_32/plugins/imageformats/libqico.a /home/kmb/Qt/5.14.0/wasm_32/plugins/imageformats/libqjpeg.a /home/kmb/Qt/5.14.0/wasm_32/plugins/imageformats/libqtga.a /home/kmb/Qt/5.14.0/wasm_32/plugins/imageformats/libqtiff.a /home/kmb/Qt/5.14.0/wasm_32/plugins/imageformats/libqwbmp.a /home/kmb/Qt/5.14.0/wasm_32/plugins/imageformats/libqwebp.a /home/kmb/Qt/5.14.0/wasm_32/qml/QtQuick.2/libqtquick2plugin.a /home/kmb/Qt/5.14.0/wasm_32/qml/QtQuick/Window.2/libwindowplugin.a /home/kmb/Qt/5.14.0/wasm_32/lib/libQt5Quick.a /home/kmb/Qt/5.14.0/wasm_32/lib/libQt5QmlModels.a /home/kmb/Qt/5.14.0/wasm_32/lib/libQt5Qml.a /home/kmb/Qt/5.14.0/wasm_32/lib/libQt5Gui.a /home/kmb/Qt/5.14.0/wasm_32/lib/libqtlibpng.a /home/kmb/Qt/5.14.0/wasm_32/lib/libqtharfbuzz.a /home/kmb/Qt/5.14.0/wasm_32/lib/libQt5Network.a /home/kmb/Qt/5.14.0/wasm_32/lib/libQt5Core.a /home/kmb/Qt/5.14.0/wasm_32/lib/libqtpcre2.a shared:ERROR: '/home/kmb/Qtwasm/emsdk/fastcomp-clang/e1.38.27_64bit/binaryen/bin/asm2wasm ./TestApp.temp.asm.js --total-memory=16777216 --trap-mode=allow -O3 --mem-init=./TestApp.js.mem --mem-base=1024 --wasm-only -o ./TestApp.wasm --mvp-features' failed (-9) Makefile:215: recipe for target 'TestApp.js' failed make: *** [TestApp.js] Error 1 so what is cuase here and i am using Ubuntu 18.04 VM kindly let me root cause

And one more problem is if one of the other basic Qt App gets compiled and build successfully and when i run it using *"emrun .html" using console i am getting application exit error as shown in image [image: eb5f2ad1-d299-4b44-bfdb-68ff30e122ca.png] So what is the reason for getting this.(I am using Firefox browser).

@lorn-potter I have checked it in qt 5.15 with em 1.39.16. but still I have same problem.

Thanks Jon, hope he sees it.

Thanks! The following code, using QFile and a top level path, did indeed work: QFile file(":/dark.qss"); file.open(QFile::ReadOnly); QTextStream stream(&file); pApp->setStyleSheet(stream.readAll());

using the latest emscripten version 1.39.11 seems to work as expected

@lorn-potter ah good to know, thanks for the information :D

Hey @lorn-potter and thanks for your reply and the provided information!

@lorn-potter you mean if I update part of my application I should download all application in my browser?

@guerinoni Thank you for sharing.

Any HTTP/HTTPS server will do. AWS, Apache, nginx, cutelyst, even simple Python/ Qt servers.

its work, thank you.

It is. Thanks.

Hi, I'm having what looks like your same issue: Widgets are not being repainted until I move the mouse. It is working well in Desktop just as in your case. Note this is not a QChart or the like, it its just a few QWidgets. Ive got a small QT WebAssembly application. (Qt 5.14.2 WebAssembly and emscripten 1.38.27-64bit). If any other one is seeing the issue and/or found out what to do about it please enlighten us :). Perhaps there is some js instruction to force the repainting or something like that. I am using a QStackedWidget; I suspect this might be an issue with this specific widget.