V2 and Props

[pauleveritt]

I'm back in "book writing" mode. I'd like to explore "props" from the previous, so I can bring my antidom repo into the book.

tl;dr Where do "props" get into injection, how are they used during instantiation?

Imagine I have "template": <p><{Greeting} name="Antidote" /></p>. This results in: <p>Hello Antidote!</p>
Hello comes from a component local variable, Antidote from a passed-in "prop", and ! is injected.

Maybe I have:

@inject
def Greeting(
        punctuation: str = inject[get_punctuation],
        customer_name: str = [MAGIC HAPPENS HERE],
) -> str:
    salutation = "Hello"
    return f"{salutation} {customer_name}{punctuation}"

Maybe I have class-based:

@injectable(scope="deterministic")
@dataclass
class Greeting:
    punctuation: str = inject[get_punctuation],
    customer_name: str = [MAGIC HAPPENS HERE],
    salutation: str = "Hello"

    def __call__(self) -> str:
        return f"{self.salutation} {self.customer_name}{self.punctuation}"

The second version offers the possibility to pass the props into the call. On one hand, that's unattractive, as results will never get cached. OTOH, the instance of these props would have to be in state somewhere. Which might be a good answer.

Or perhaps I need to write a provider. Maybe I need to anyway, to customize the .update of injection?

Last point: a prop should be able to override an injected value. In the above, I should be able to pass in my own punctuation for a specific usage: <p><{Greeting} name="Antidote" punctuation="??" /></p>

[pauleveritt]

Note: Added an important "last point" at the end.

[Finistere]

I think @lazy does what you're searching for:

from antidote import const, inject, lazy, world


class Conf:
    PUNCTUATION = const('!')


@lazy
def Greeting(name: str, punctuation: str = inject[Conf.PUNCTUATION]) -> str:
    return f"<p>Hello {name}{punctuation}</p>"


assert world[Greeting(name='Antidote')] == "<p>Hello Antidote!</p>"
assert world[Greeting(name='someone', punctuation='???')] == "<p>Hello someone???</p>"