Struct async_graphql::ContextBase

pub struct ContextBase<'a, T> {
    pub path_node: Option<QueryPathNode<'a>>,
    // some fields omitted
}

Query context

Fields

path_node: Option<QueryPathNode<'a>>

Implementations

impl<'a, T> ContextBase<'a, T>

pub fn data<D: Any + Send + Sync>(&self) -> &D

Gets the global data defined in the Context or Schema.

If both Schema and Query have the same data type, the data in the Query is obtained.

Panics

It will panic if the specified data type does not exist.

pub fn data_opt<D: Any + Send + Sync>(&self) -> Option<&D>

Gets the global data defined in the Context or Schema, returns None if the specified type data does not exist.

impl<'a> ContextBase<'a, &'a Positioned<Field>>

pub fn position(&self) -> Pos

Get the position of the current field in the query code.

pub fn look_ahead(&self) -> Lookahead

Creates a uniform interface to inspect the forthcoming selections.

Examples

use async_graphql::*;

#[SimpleObject]
struct Detail {
    c: i32,
    d: i32,
}

#[SimpleObject]
struct MyObj {
    a: i32,
    b: i32,
    detail: Detail,
}

struct Query;

#[Object]
impl Query {
    async fn obj(&self, ctx: &Context<'_>) -> MyObj {
        if ctx.look_ahead().field("a").exists() {
            // This is a query like `obj { a }`
        } else if ctx.look_ahead().field("detail").field("c").exists() {
            // This is a query like `obj { detail { c } }`
        } else {
            // This query doesn't have `a`
        }
        unimplemented!()
    }
}

Trait Implementations

impl<'a, T: Clone> Clone for ContextBase<'a, T>

fn clone(&self) -> ContextBase<'a, T>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<'a, T> Deref for ContextBase<'a, T>

type Target = T

The resulting type after dereferencing.

fn deref(&self) -> &Self::Target

Dereferences the value.