Struct BindingValue 

pub struct BindingValue<T> { /* private fields */ }

A value passed into a binding: a value, an “unset”/“do nothing” marker, or an error with an optional fallback value.

Implementations

impl<T> BindingValue<T>

pub fn new(value: T) -> Self

Creates a binding value holding a simple value.

pub fn unset() -> Self

A binding value representing the unset state.

pub fn do_nothing() -> Self

A binding value that is ignored by its target.

pub fn binding_error(error: BindingError) -> Self

A binding error without a fallback value.

pub fn binding_error_with_fallback( error: BindingError, fallback: Option<T>, ) -> Self

A binding error with an optional fallback value.

pub fn data_validation_error(error: BindingError) -> Self

A data validation error without a fallback value.

pub fn data_validation_error_with_fallback( error: BindingError, fallback: Option<T>, ) -> Self

A data validation error with an optional fallback value.

pub fn has_value(&self) -> bool

Whether the binding value carries a value (or fallback value).

pub fn has_error(&self) -> bool

Whether the binding value carries an error.

pub fn value_type(&self) -> BindingValueType

pub fn value(&self) -> &T

The value. Panics if there is none, see has_value.

pub fn error(&self) -> Option<&BindingError>

pub fn into_option(self) -> Option<T>

Converts into the contained value, if any.

pub fn get_value_or_default(self, default: T) -> T

Returns the value, or default if there is none.

pub fn with_value(self, value: T) -> Self

Returns a binding value with the same error state and a new value. For error states this turns them into their “with fallback” variants.

pub fn map<U>(self, f: impl FnOnce(T) -> U) -> BindingValue<U>

Maps the contained value, keeping the state.

impl<T: Clone> BindingValue<T>

pub fn to_optional(&self) -> Option<T>

Converts the binding value to an optional value: the value (or fallback value), if there is one.

pub fn get_value_or_default_option(&self) -> Option<T>

Gets the value of the binding value if present, otherwise the default value: none.

impl<T: Clone + 'static> BindingValue<T>

pub fn get_value_or_default_as<TResult: Clone + 'static>( &self, ) -> Option<TResult>

Gets the value of the binding value if it is present and of type TResult, otherwise the default value: none.

pub fn get_value_or_default_as_or<TResult: Clone + 'static>( &self, default_value: TResult, ) -> Option<TResult>

Gets the value of the binding value if it is present and of type TResult; none if it is present and of another type; default_value if there is no value.

impl<T: PropertyValue> BindingValue<T>

pub fn to_untyped(&self) -> Option<BoxedValue>

Converts the value to untyped representation, using the unset and do-nothing markers and BindingNotification where appropriate.

Panics

Panics if the type of the binding value is none of the kinds BindingValueType declares.

pub fn from_untyped(value: Option<&BoxedValue>) -> Self

Creates a binding value from an untyped value: the unset or do-nothing marker, a BindingNotification, or a value that converts implicitly to T.

pub fn from_untyped_with_type( value: Option<&BoxedValue>, target_type: ValueType, ) -> Self

Creates a binding value from an untyped value, converting the value to target_type.

A value that does not convert to target_type, or whose conversion is not a T, gives a binding error. Null converts only to a target type that has a null value of its own (a nullable form): T itself is never null here.

Trait Implementations

impl<T: Clone> Clone for BindingValue<T>

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<T: Debug> Debug for BindingValue<T>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<T: Display> Display for BindingValue<T>

The text of the binding value: Error: <message> for an error, the text of the value, or (null) without a value.

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<T> From<Option<T>> for BindingValue<T>

fn from(value: Option<T>) -> Self

None maps to the unset state.

impl<T> From<T> for BindingValue<T>

fn from(value: T) -> Self

Converts to this type from the input type.

impl<T: PartialEq> PartialEq for BindingValue<T>

fn eq(&self, other: &Self) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl<T: PartialEq> StructuralPartialEq for BindingValue<T>