With time, we realised that hiding the abstraction of the web development to make it look like desktop was not so great: since the beginning of Libervia, the web ecosystem had improved greatly (HTML 5 and CSS things like flexbox notably), and it was getting hard to use the novelties. The application was not responsive and unusable on mobile, while phone was getting the main platform for many people.
In addition, 2 major issues were resulting in a dead end for Pyjamas: first a hijack of the project (not just hostile fork, but true hijack: the official website has been redirected to the fork named pyjs without the consent of the main contributor of Pyjamas, and the mailing list has been redirected without the consent of its subscribers), and second Pyjamas was stuck with Python 2, and a Python 3 port would mean a nearly full rewrite.
We have been carefully checking the various options, and our favorite candidates were Brython and Transcrypt.
Brython on the other hand is doing the transpilation in the browser, it is like having a Python interpreter in the browser. Its has some decisive (for us) advantages: full Python compatibility, and the possibility to dynamically convert Python to JS. The Python compatibility is essential to factorise the code with other frontends, and the ability to convert Python to JS open the way for future use (like sharing code during a chat, e.g. for a school or scientific use). I've been following the Brython community for years, it is really friendly and dynamic, and the few issues I've reported online were addressed quickly.
So Brython has been chosen as the main way to do dynamic code in the Libervia web framework, but it is possible to switch to something else. To use it, it is as simple as writing some Python in a
__init__.py file in a
_browser directory of a page ; Libervia will take care of installing Brython, copying and loading the script.
As an example, here is how you would show an alert if somebody click on an element with
from browser import bind,alert
alert("click on an author")
npm (whichever is present on the system). A common JSON file is used to indicate dependencies (using the syntax of
package.json well known by frontend developers), and potentially how to generate corresponding Brython module. Sass has been integrated too.
I've also worked on themes, but I don't want to make this blog post too long to write and read, so I'll talk about that next time.