rx.cond in style

[a0s]

Describe the bug I'm not entirely sure if this is a bug or if I'm doing something it's not designed for.

I need style with condition. When i try to do smth like this:

rx.image(
    src="/logoipsum-263.svg",
    style=rx.cond(
        TopBarState.is_debug,
        Style({"border": "1px solid red"}),
        Style({}),
    )
)

or even simple

rx.image(
    src="/logoipsum-263.svg",
    style=rx.cond(
        TopBarState.is_debug,
        {"border": "1px solid red"},
        {},
    )
)

i am getting:

[skipped] site-packages/reflex/components/component.py", line 352, in __init__

TypeError: 'BaseVar' object is not a mapping

[skipped]

TypeError: You may be trying to use an invalid Python function on a state var. When referencing a var inside your render code, only limited var operations are supported. See the var operation docs here

The error contains no useful information, except that rx.cond does not seem to be able to work with the Style() type?

Version: reflex==0.4.6

[PasqualePuzio]

I think the best way to do that is to use rx.cond for keywors arguments. At least that's how we do it and it works perfectly.

For instance:

rx.image(
    src='...',
    width=rx.cond(MyState.my_var,width1,width2),
)

[a0s]

No, it doesn't work for style=

class TopBarState(rx.State):
    is_debug: bool
    debug_enabled: dict[str, str] = {
        "border": "1px solid red"
    }
    debug_disabled: dict[str, str] = {}

rx.image(
  src="/logoipsum-263.svg",
  height="3rem",
  style=rx.cond(
      TopBarState.is_debug,
      TopBarState.debug_enabled,
      TopBarState.debug_disabled,
  ),

got me the same error TypeError: 'BaseVar' object is not a mapping

[PasqualePuzio]

Yeah, what I meant is that instead of passing a style dict you could use rx.cond for every single property. That will probably fix your bug.

[Lendemor]

class DebugState(rx.State):
    enabled: bool

    def toggle(self, _):
        self.enabled = not self.enabled


@rx.page()
def index():
    return rx.vstack(
        rx.switch(on_change=DebugState.toggle),
        rx.image(
            src="favicon.ico",
            style={
                "border": rx.cond(DebugState.enabled, "1px solid red", ""),
            },
        ),
    )

[a0s]

@Lendemor yeah, thank you, this is the only way i found. Ofc, it would be better if rx.cond supports Style() class as one of set of native operands..