This is a follow-up of PR #806 and it's a big step forward towards solving issue #763.
The basic idea is that at this stage I want to streamline the execution logic
and make it as linear and easy to read/understand as possible. The diff is
relatively big, but for the most part is just "shuffling code around".
Svelte stores:
the idea is to eventually kill of them, so that we can remove the dependency
on svelte but also to avoid relying on so much global state, which makes
things more complicated and error-prone (e.g., we have several issues related
to using runtime when it's not ready yet).
I killed addInitializer, addPostInitializer and the corresponding svelte
stores tada. They are no longer needed since the relevant code is called
directly from main.ts.
I started to kill the usage of the runtimeLoaded svelte store: instead of
relying on a global variable, I want to arrive at the point in which the
runtime is passed as a parameter in all places where it's needed: pyscript.ts
is now free of global state, but I couldn't kill it yet because it's used
heavily by base.ts and pyrepl.ts. I will do it in another PR.
Other misc changes:
I added sanity checks (and corresponding tests!) which complain if you specify
0 or multiple runtimes. Currently we support having one and only one, so there
is no point to pretend otherwise
I modified the messages displayed by the loader, to be more informative from
the user point of view.
This PR is the first step to improve and rationalize the life-cycle of a pyscript app along the lines of what I described in #763 .
It is not a complete solution, more PRs will follow.
Highlights:
- py-config is no longer a web component: the old code relied on PyConfig.connectedCallback to do some logic, but then if no <py-config> tag was present, we had to introduce a dummy one with the sole goal of activating the callback. Now the logic is much more linear.
- the new pyconfig.ts only contains the code which is needed to parse the config; I also moved some relevant code from utils.ts because it didn't really belong to it
- the old PyConfig class did much more than dealing with the config: in particular, it contained the code to initialize the env and the runtime. Now this logic has been moved directly into main.ts, inside the new PyScriptApp class. I plan to refactor the initialization code in further PRs
- the current code relies too much on global state and global variables, they are everywhere. This PR is a first step to solve the problem by introducing a PyScriptApp class, which will hold all the mutable state of the page. Currently only config is stored there, but eventually I will migrate more state to it, until we will have only one global singleton, globalApp
- thanks to what I described above, I could kill the appConfig svelte store: one less store to kill :).
