Struct juniper::FieldError

pub struct FieldError { /* fields omitted */ }

Error type for errors that occur during field resolution

Field errors are represented by a human-readable error message and an optional Value structure containing additional information.

They can be converted to from any type that implements std::fmt::Display, which makes error chaining with the ? operator a breeze:

fn get_string(data: Vec<u8>) -> Result<String, FieldError> {
    let s = String::from_utf8(data)?;
    Ok(s)
}

Methods

impl FieldError

pub fn new<T: Display>(e: T, data: Value) -> FieldError

Construct a new error with additional data

You can use the graphql_value! macro to construct an error:

use juniper::FieldError;

FieldError::new(
    "Could not open connection to the database",
    graphql_value!({ "internal_error": "Connection refused" })
);

The data parameter will be added to the "data" field of the error object in the JSON response:

{
  "errors": [
    "message": "Could not open connection to the database",
    "locations": [{"line": 2, "column": 4}],
    "data": {
      "internal_error": "Connection refused"
    }
  ]
}

If the argument is Value::null(), no extra data will be included.

Trait Implementations

impl Debug for FieldError

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

Formats the value using the given formatter.

impl PartialEq for FieldError

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

This method tests for self and other values to be equal, and is used by ==.

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

This method tests for !=.

impl<T: Display> From<T> for FieldError

fn from(e: T) -> FieldError

Performs the conversion.