Qt for WebAssembly

Hi, Even simpler use Qt's OS defines: Q_OS_WASM: #ifdef Q_OS_WASM // You WASM specific code #endif

QtMqtt will not work out of the box with WebAssembly, you do need to use a WebSocket IODevice, and use an MQTT broker that supports websocket connections. https://qtandeverything.blogspot.com/2019/08/qmqtt-qwebassembly.html

Qt3D is not supported in Qt WebAssembly, so no work has been done to make it work. Qt3D requires OpenGL (desktop) and WebAssembly only supports OpenGL ES2/3, so I doubt it would even build correctly.

Sadly, this is a known bug. I thought there was already a bug report about it, but I could not find one, so I started a new one: https://bugreports.qt.io/browse/QTBUG-83503

Thanks, I have applied the patches to 5.14.2 and my test app compiles now.

The wiki has updated instructions for the new emscripten labels: https://wiki.qt.io/Qt_for_WebAssembly ./emsdk install sdk-fastcomp-1.38.27-64bit ./emsdk activate sdk-fastcomp-1.38.27-64bit

Ok, I found the solution. Thanks to: https://stackoverflow.com/questions/56886410/access-local-user-file-on-qt-for-web-assembly So, with the help of: https://doc.qt.io/qt-5/qfiledialog.html#getOpenFileContent

Both I'd say but more the fact that its new as once you have the build out of the way then that part falls away. Just starting out with it though so maybe the second one is not that big an issue.

@lorn-potter It's working... Woohoo, thanks! Now it builds. I just built simple QML :)

@AlsaniePss please try right clicking the 3 vertical dots at the right of the post...

@wild-linkle said in CUPS for WebAssembly: getpwnam Wasm lives in the same sandbox as javascript. Accessing printers and other hardware is not supported at this time.

There is a library called QtWebApp which allows you to set up a server and it is pretty good for small-medium projects. t has examples and a great tutorial on the official site there. I don't really know how Angular works and I've never tried it so tell me if this is what you needed or not.

Emscripten/wasm does not have access to the kernel, so trying to build kernel modules for wasm will not work. It lives in the web browser sandbox alongside javascript.

@Triomphe Please explain clearly what you want to do. In what way do you want to "edit the Qlistwidget item"?

@sierdzio That is indeed the issue. I went to the wrong directory choosing the opensource version (with the old installer etc. ...). I'm donwloading and can even download Webassembly. Thanks for your help!!!

Hello, I am having the same issue. Did you manage to solve it ? Thank you

@lorn-potter For the notes app I'm thinking I want to have a page with three buttons with C++ functions connected to them where the first would add a textarea along with a button to save a note and a button to delete a note; the second one to let the user delete a note (works the same as the aforementioned one: shows a list of notes in a modal dialog box where the user can select one or more (adjacent) notes and delete them); and the third to browse notes (of course if the user decides he/she delete a note from the list while browsing, he/she should be able to do so). Originally I was thinking I'd use QML but I want to try this in regular HTML, with CSS and JavaScript (I'll just write the C++ code and have Emscripten take care of the HTML and JavaScript, though). So is this possible like what I described? If so, I'd like some help with this. Thanks.

For your undefined symbols, sometimes this is all that needs to be done: replace #include <QObject> with #include <QtCore/QObject> Unfortunately, I am still searching how to do this with my custom headers, as that is throwing me the undefined symbol errors. #include "myclass.h" Is not working.