Struct RestrictFormats

#[non_exhaustive]
pub struct RestrictFormats {
    pub infer_from_meta_schema: bool,
    pub allowed_formats: BTreeSet<Cow<'static, str>>,
}

Removes any format values that are not defined by the JSON Schema standard or explicitly allowed by a custom list.

This also applies to subschemas.

By default, this will infer the version of JSON Schema from the schema’s $schema property, and no additional formats will be allowed (even when the JSON schema allows nonstandard formats).

Example

use schemars::json_schema;
use schemars::transform::{RestrictFormats, Transform};

let mut schema = schemars::json_schema!({
    "$schema": "https://json-schema.org/draft/2020-12/schema",
    "anyOf": [
        {
            "type": "string",
            "format": "uuid"
        },
        {
            "$schema": "http://json-schema.org/draft-07/schema#",
            "type": "string",
            "format": "uuid"
        },
        {
            "type": "string",
            "format": "allowed-custom-format"
        },
        {
            "type": "string",
            "format": "forbidden-custom-format"
        }
    ]
});

let mut transform = RestrictFormats::default();
transform.allowed_formats.insert("allowed-custom-format".into());
transform.transform(&mut schema);

assert_eq!(
    schema,
    json_schema!({
        "$schema": "https://json-schema.org/draft/2020-12/schema",
        "anyOf": [
            {
                // "uuid" format is defined in draft 2020-12.
                "type": "string",
                "format": "uuid"
            },
            {
                // "uuid" format is not defined in draft-07, so is removed from this subschema.
                "$schema": "http://json-schema.org/draft-07/schema#",
                "type": "string"
            },
            {
                // "allowed-custom-format" format was present in `allowed_formats`...
                "type": "string",
                "format": "allowed-custom-format"
            },
            {
                // ...but "forbidden-custom-format" format was not, so is also removed.
                "type": "string"
            }
        ]
    })
);

Fields (Non-exhaustive)

Non-exhaustive structs could have additional fields added in future. Therefore, non-exhaustive structs cannot be constructed in external crates using the traditional Struct { .. } syntax; cannot be matched against without a wildcard ..; and struct update syntax will not work.

infer_from_meta_schema: bool

Whether to read the schema’s $schema property to determine which version of JSON Schema is being used, and allow only formats defined in that standard. If this is true but the JSON Schema version can’t be determined because $schema is missing or unknown, then no format values will be removed.

If this is set to false, then only the formats explicitly included in allowed_formats will be allowed.

By default, this is true.

allowed_formats: BTreeSet<Cow<'static, str>>

Values of the format property in schemas that will always be allowed, regardless of the inferred version of JSON Schema.

Trait Implementations

impl Clone for RestrictFormats

fn clone(&self) -> RestrictFormats

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for RestrictFormats

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

Formats the value using the given formatter.

impl Default for RestrictFormats

fn default() -> Self

Returns the “default value” for a type.

impl Transform for RestrictFormats

fn transform(&mut self, schema: &mut Schema)

Applies the transform to the given Schema.