reflex export fails on clean repository as database is missing

[luator]

Hello,
I'm currently trying to get my application working with docker (following the production-compose example) and am struggling with an error during the export step.

My application is using an sqlite database. When running reflex export --frontend-only on a clean repository (where the database is not created yet), it fails with an error coming from the reflex-local-auth plugin (reflex_local_auth/lo
cal_auth.py, line 36), complaining that

no such table: localuser

Now I assume this is not necessarily an issue of the reflex-local-auth plugin itself but more of how I use it in my code. Probably I'm accessing some State data in a wrong way somewhere? Can you give me a hint what I should be looking for and how I can avoid this error?

[luator]

I could narrow it down to the usage of reflex_local_auth.LocalAuthState.is_authenticated when constructing the pages, i.e. something like this:

rx.cond(
    reflex_local_auth.LocalAuthState.is_authenticated,
    rx.text("You're logged in"),
    rx.text("You're not logged in"),
),

What would be the correct way to achieve this (i.e. conditionally show some elements on the page depending on whether the user is logged in or not)?

[luator]

I just realized that reflex run gives the same error when the database doesn't exist yet (which I guess makes sense). So it's not limited to reflex export.

[luator]

I got it working now by calling reflex db migrate before the reflex export step. Is this the correct way of doing it? Or can I avoid it by changing something in my implementation?

[larsblumberg]

Since you want reproducible builds via docker on build systems, I suggest to allow reflex export w/o requiring a running database. Since reflex export executes your pages and components in order to compile the frontend code, I suggest that you properly handle the database connection errors (or whatever errors that is) and allow the rendering of your pages w/o an error. In your specific case reflex_local_auth.LocalAuthState.is_authenticated should return False when it couldn't connect to the database. Possibly you may need to address a more deeper laying problem, but the solution I suggest is only based on what you have shared above.

[luator]

Thanks for the suggestion. Indeed, catching the error in reflex_local_auth.LocalAuthState.authenticated_user was all that is needed to make the export succeed without database. Since this is not my code, I opened an issue on the corresponding repo: masenf/reflex-local-auth#18

[benedikt-bartscher]

try using the initial_value argument of @rx.var to prevent db queries during compilation

[luator]

Thanks for the suggestion, but could you explain what this argument exactly does? I couldn't find anything in the documentation.

[benedikt-bartscher]

It skips the calculation of the computed var during compilation of initial app state payloads. This way the computed var is only executed during runtime and not during compilation where a database is not present/wanted.

[luator]

It doesn't seem to work unfortunately. I tried setting it for reflex_local_auth.LocalAuthState.authenticated_user() but the function still get's executed during reflex export (i.e. I get an exception from inside that function).