With typing hints, can Prefect handle more complicated hints for the UI? If, for example, I’d like to have a list of some pydantic basemodel, could Prefect process that to show the various fields?

Not sure about the actual answer to your question, but is something you could use blocks for? Or would it have to be passed in as a parameter?

It’s a parameter, and mostly just a UI question about the capabilities for Prefect. It’ll be nice to have it available as such, rather than having to specify a JSON format.

Ah, I gotcha. I'm curious to know the answer too, I agree it'd be nicer to handle it that way than via JSON

Enum are displayed as Drop down. The deployment specs has open api params. Maybe you can look into that?

if you have a pydantic model as an input like

class Foo(BaseModel):
    a: int
    b: int

class Input(BaseModel):
    foo: Foo
    bar: str

@flow(log_prints=True)
def my_flow(input: Input) -> None:
    print(f"got input: {input!r}")

then the form will show up nicely in the UI with each field of

Input

(including the nested models), but if you have a

list[Input]

then the input in the UI will be a freeform JSON field. perhaps you could adjust the model you're passing in so that it contains your lists instead of passing a list of the models?

Would that work? If e.g. it was

foo: List[Foo]

?

hmm actually it seems like whenever there's a

list[Model]

its going to be a freeform JSON field like (image is the Quick Run form for this deployment)

from prefect import flow

from pydantic import BaseModel

class Foo(BaseModel):
    a: int
    b: int

class Input(BaseModel):
    foo: list[Foo]
    bar: str

@flow(log_prints=True)
def my_flow(input: Input) -> None:
    print(f"got input: {input!r}")

# prefect deploy typehints.py:my_flow

That's a pity :( any alternatives? Could one leverage

*args

for this? 🤔

what is it that you're trying to do? do you plan on spending a lot of time in the UI filling out the forms for flow runs?

Just trying to use the UI for the less tech-oriented staff, so that they may run production flows themselves

makes sense! requirement about lists of models aside, seems like you could do

from prefect import flow

from pydantic import BaseModel, Field

class Input(BaseModel):
    foo: int = Field(..., description="foo is a required field")
    bar: bool = Field(False, description="whether to bar or not")
    baz: list = Field(default_factory=list, description="a list of bazzes")

@flow(log_prints=True)
def my_flow(user_input: Input) -> None:
    print(f"got input: {user_input!r}")

Hello I'd like to bar please. Yes! This looks like a good compromise, thanks! Any idea about future UI support for lists? Just to one-up this?

i don't know about future plans for the UI here, perhaps @Craig Harshbarger would have some input (pun intended)

This is mostly a

List[...]

question. Currently we don't have any ui to handle lists unless there is an

enum

and then we give you a drop down. We would have to add some ui to visually let you add/remove values and render the schema for the model in the list. Which gets a little tricky considering there can be unions and such. But its possible! Just not a priority at the moment. But if this is something you'd like to see please open a github issue for it and if there are others that want this that will help us set an accurate priority.

Thanks @Craig Harshbarger! I've seen this before where usually there's simply "add" and "remove" buttons, that open a new item with the designated schema. I'll put a reminder to create a GH issue for this, would be a nice feature to have!

is there a way to maintain docstring structure?

hmm I'm not quite sure what you mean, could you show an example? of what you mean by

a sample JSON with explanation for the different kwargs

Let’s say I’d like to have:

class Input(BaseModel):
    a: SomeOtherClass = Field(..., description="""A foo that bars some bazzes, with the following structure:
{
  # You may specify your foo as an integer here
  "foo": Optional[int]
  "bar": {
    # Your baz goes here
    "baz": str
    "should_baz": bool = False
  }
}
""")

This results in a single line, even though I’d like to maintain the multi-line description

Can you verify if its coming from the api in the way you'd expect? Curious if it is the ui or api that is removing the formatting.

Could you direct me how to check that?

If you look at the deployment in the network tab. Basically just looking for what json the api is returning.

Hm, I don’t see anything like that in the network tab 🤔

Sorry for the delay. Was on vacation and just catching back up on things. If this is still happening could you please create a github issue with a minimum reproduction? That's the best way to get this picked up and fixed.

Sorry, I was also away on vacation. The ticketing list requires to verify with a different browser 🤔 I find that a bit discouraging, I don’t hold multiple browsers on my end and would prefer to refrain from installing additional ones 🙈