Widgets¶

`fastapi_admin_kit.widgets.base.Widget` ¶

Base widget class.

Stateless: receives FieldMeta + value at render/validate time. Override parse to transform raw form data. Override validate to add custom validation. Override render_context to customise template variables.

Source code in fastapi_admin_kit/widgets/base.py

class Widget:
    """Base widget class.

    Stateless: receives FieldMeta + value at render/validate time.
    Override ``parse`` to transform raw form data.
    Override ``validate`` to add custom validation.
    Override ``render_context`` to customise template variables.
    """

    macro_name: str = "text_input"

    def render_context(self, field: FieldMeta, value: Any) -> dict:
        """Variables injected into the Jinja2 macro."""
        return {
            "field": field,
            "value": value if value is not None else "",
            "id": f"field-{field.name}",
            "name": field.name,
        }

    def parse(self, raw: str | list | None) -> Any:
        """Convert raw FormData string to typed Python value."""
        if raw is None or raw == "":
            return None
        return raw

    def validate(self, value: Any, field: FieldMeta) -> list[str]:
        """Return a list of error messages. Empty list means valid."""
        errors: list[str] = []
        if field.required and (value is None or value == ""):
            errors.append(f"{field.label} is required.")
        return errors

    def __repr__(self) -> str:
        return f"<{self.__class__.__name__} macro={self.macro_name!r}>"

`render_context(field, value)` ¶

Variables injected into the Jinja2 macro.

Source code in fastapi_admin_kit/widgets/base.py

def render_context(self, field: FieldMeta, value: Any) -> dict:
    """Variables injected into the Jinja2 macro."""
    return {
        "field": field,
        "value": value if value is not None else "",
        "id": f"field-{field.name}",
        "name": field.name,
    }

`parse(raw)` ¶

Convert raw FormData string to typed Python value.

Source code in fastapi_admin_kit/widgets/base.py

def parse(self, raw: str | list | None) -> Any:
    """Convert raw FormData string to typed Python value."""
    if raw is None or raw == "":
        return None
    return raw

`validate(value, field)` ¶

Return a list of error messages. Empty list means valid.

Source code in fastapi_admin_kit/widgets/base.py

def validate(self, value: Any, field: FieldMeta) -> list[str]:
    """Return a list of error messages. Empty list means valid."""
    errors: list[str] = []
    if field.required and (value is None or value == ""):
        errors.append(f"{field.label} is required.")
    return errors

FieldMeta¶

`fastapi_admin_kit.widgets.base.FieldMeta` `dataclass` ¶

Metadata for a form field — drives widget rendering and validation.

Source code in fastapi_admin_kit/types.py

@dataclass
class FieldMeta:
    """Metadata for a form field — drives widget rendering and validation."""

    name: str
    label: str
    required: bool
    readonly: bool = False
    help_text: str | None = None
    placeholder: str | None = None
    extra: dict = field(default_factory=dict)