Enum Rule 

pub enum Rule {
    Required,
    Present,
    NotNull,
    String,
    Integer,
    Numeric,
    Boolean,
    Array,
    Min(f64),
    Max(f64),
    Size(f64),
    Between(f64, f64),
    Email,
    Url,
    Slug,
    Uuid,
    Alpha,
    AlphaNumeric,
    AlphaDash,
    In(Vec<String>),
    NotIn(Vec<String>),
    StartsWith(String),
    EndsWith(String),
    Date,
    After(NaiveDate),
    Before(NaiveDate),
    Confirmed,
    Same(String),
    Different(String),
    Custom {
        message: String,
        check: Arc<dyn Fn(&Value) -> bool + Send + Sync>,
    },
}

One validation rule.

Variants

Required

Present, not null, and not empty.

Present

Present (may be null or empty).

NotNull

Not null when present.

String

A string (or a value that reads as one).

Integer

An integer.

Numeric

A number, integer or not.

Boolean

A boolean, or one of the strings a form sends for one.

Array

An array.

Min(f64)

At least this length: characters for a string, elements for an array, value for a number.

Max(f64)

At most this length, by the same measure as Rule::Min.

Size(f64)

Exactly this length.

Between(f64, f64)

Between these bounds, inclusive.

Email

A plausible email address.

Url

An absolute http/https URL.

Slug

Letters, digits, - and _.

Uuid

A canonical UUID.

Alpha

ASCII letters only.

AlphaNumeric

ASCII letters and digits.

AlphaDash

Letters, digits, - and _.

In(Vec<String>)

One of these values.

NotIn(Vec<String>)

None of these values.

StartsWith(String)

Starts with this prefix.

EndsWith(String)

Ends with this suffix.

Date

A YYYY-MM-DD date.

After(NaiveDate)

A date on or after this one.

Before(NaiveDate)

A date on or before this one.

Confirmed

Equal to another field’s value — password_confirmation.

Same(String)

Equal to the named field’s value.

Different(String)

Different from the named field’s value.

Custom

Any predicate, with the message to use when it fails.

Fields

message: String

Shown when the predicate returns false.

check: Arc<dyn Fn(&Value) -> bool + Send + Sync>

The predicate.

Implementations

impl Rule

pub fn name(&self) -> &'static str

The rule’s name, as it appears in a failure message.

pub fn applies_to_missing(&self) -> bool

Whether this rule cares about a value that is absent or null.

Only the presence rules do. Everything else defers to them, which is what makes optional fields work without a rule combinator.

pub fn check(&self, field: &str, value: Option<&Value>, all: &Value) -> Outcome

Check value (the field being validated) against this rule.

field names it for the message, and all is the whole input, which the cross-field rules need.

Trait Implementations

impl Clone for Rule

fn clone(&self) -> Self

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.