Struct async_graphql::Lookahead

pub struct Lookahead<'a> { /* private fields */ }

A selection performed by a query.

Implementations

impl<'a> Lookahead<'a>

pub fn field(&self, name: &str) -> Self

Get the field of the selection set with the specified name. This will ignore aliases.

For example, calling .field("a") on { a { b } } will return a lookahead that represents { b }.

pub fn exists(&self) -> bool

Returns true if field exists otherwise return false.

pub fn selection_fields(&self) -> Vec<SelectionField<'a>>

Get the SelectionFields for each of the fields covered by this Lookahead.

There will be multiple fields in situations where the same field is queried twice.

Trait Implementations

impl<'a> From<SelectionField<'a>> for Lookahead<'a>

fn from(selection_field: SelectionField<'a>) -> Self

Converts to this type from the input type.

impl<'a> TryFrom<&[SelectionField<'a>]> for Lookahead<'a>

Convert a slice of SelectionFields to a Lookahead. Assumes all SelectionFields are from the same query and thus have the same fragments.

Fails if either no SelectionFields were provided.

type Error = ()

The type returned in the event of a conversion error.

fn try_from( selection_fields: &[SelectionField<'a>], ) -> Result<Self, Self::Error>

Performs the conversion.