Struct Rule

pub struct Rule {
    pub id: Option<String>,
    pub message: Option<String>,
    pub expression: Option<String>,
}

Rule represents a validation rule written in the Common Expression Language (CEL) syntax. Each Rule includes a unique identifier, an optional error message, and the CEL expression to evaluate. For more information on CEL, see our documentation.

message Foo {
   option (buf.validate.message).cel = {
     id: "foo.bar"
     message: "bar must be greater than 0"
     expression: "this.bar > 0"
   };
   int32 bar = 1;
}

Fields

id: Option<String>

id is a string that serves as a machine-readable name for this Rule. It should be unique within its scope, which could be either a message or a field.

message: Option<String>

message is an optional field that provides a human-readable error message for this Rule when the CEL expression evaluates to false. If a non-empty message is provided, any strings resulting from the CEL expression evaluation are ignored.

expression: Option<String>

expression is the actual CEL expression that will be evaluated for validation. This string must resolve to either a boolean or a string value. If the expression evaluates to false or a non-empty string, the validation is considered failed, and the message is rejected.

Implementations

impl Rule

pub fn id(&self) -> &str

Returns the value of id, or the default value if id is unset.

pub fn message(&self) -> &str

Returns the value of message, or the default value if message is unset.

pub fn expression(&self) -> &str

Returns the value of expression, or the default value if expression is unset.

Trait Implementations

impl Clone for Rule

fn clone(&self) -> Rule

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Rule

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

Formats the value using the given formatter.

impl Default for Rule

fn default() -> Self

Returns the “default value” for a type.

impl Message for Rule

fn encoded_len(&self) -> usize

Returns the encoded length of the message without a length delimiter.

fn clear(&mut self)

Clears the message, resetting all fields to their default.

fn encode(&self, buf: &mut impl BufMut) -> Result<(), EncodeError>

where Self: Sized,

Encodes the message to a buffer.

fn encode_to_vec(&self) -> Vec<u8>

where Self: Sized,

Encodes the message to a newly allocated buffer.

fn encode_length_delimited( &self, buf: &mut impl BufMut, ) -> Result<(), EncodeError>

where Self: Sized,

Encodes the message with a length-delimiter to a buffer.

fn encode_length_delimited_to_vec(&self) -> Vec<u8>

where Self: Sized,

Encodes the message with a length-delimiter to a newly allocated buffer.

fn decode(buf: impl Buf) -> Result<Self, DecodeError>

where Self: Default,

Decodes an instance of the message from a buffer.

fn decode_length_delimited(buf: impl Buf) -> Result<Self, DecodeError>

where Self: Default,

Decodes a length-delimited instance of the message from the buffer.

fn merge(&mut self, buf: impl Buf) -> Result<(), DecodeError>

where Self: Sized,

Decodes an instance of the message from a buffer, and merges it into self.

fn merge_length_delimited(&mut self, buf: impl Buf) -> Result<(), DecodeError>

where Self: Sized,

Decodes a length-delimited instance of the message from buffer, and merges it into self.

impl PartialEq for Rule

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

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for Rule