JSON Schema

The rules that JSON Schema can express are described by its keywords, so the generators of the schemas of an API can show them to the clients: huma puts them into its OpenAPI document. v.Constraints() returns them for other generators.

for _, c := range v.Constraints() {
    fmt.Println(c.Struct, c.Field.GetStructPath(), c.Path, c.Keyword, c.Value)
}

Every shared.Constraint has the configured struct, the field, the path from the schema of the field to the constrained value — [items] for the elements of a slice, [additionalProperties] for the values of a map, [propertyNames] for its keys — the keyword and its value. The keyword required means the field is in the required properties of its object.

Rules	Keywords
str: Required	required, minLength: 1
str: MinRunes, MaxRunes, MaxLen	minLength, maxLength
str: Regexp, Prefix, Suffix, Contains, Alphanumeric, Alpha, Digits, Numeric, Hexadecimal, Semver, E164, HexColor	pattern
str: Email, URL, IPv4, IPv6, Hostname, UUID	format: email, uri, ipv4, ipv6, hostname, uuid
str: Datetime(time.RFC3339), Datetime(time.DateOnly)	format: date-time, date
str: Base64, Base64URL	contentEncoding
str, num, uuid: AnyOf; eq: OneOf	enum
eq: Equal	const
num: Min, Max, AnyOfInterval, Latitude, Longitude, GreaterThan, LessThan	minimum, maximum, exclusiveMinimum, exclusiveMaximum
num, eq, uuid: Required	required
slices: Required, MinLen, MaxLen, Unique, Each	required and minItems: 1, minItems, maxItems, uniqueItems, items
maps: Required, MinLen, MaxLen, EachKey, EachValue	required and minProperties: 1, minProperties, maxProperties, propertyNames, additionalProperties

The schema describes the rules, valigo validates the values: the descriptions are chosen not to be stricter than the rules, so a value valid for valigo is valid for the schema. The formats are annotations of JSON Schema, the validators that check them can differ in details.

• MinLen of strings counts bytes, minLength counts characters: it isn't described. MaxLen is maxLength, a string of n bytes has no more than n characters.
• The rules under When of the struct and of fields aren't described, they don't apply to every value.
• After Trim and other Modify rules only Required is described: the schema describes the value of the request, the rules check the modified one.
• Rules on other fields, custom rules and the formats without a keyword of JSON Schema aren't described.

Your conversions

A conversion describes its rules by Schema of the field, Schema of a slice configurator describes the rules of the slice:

// Percent checks that the number is in [0, 100].
func (c *RatioConfigurator) Percent() *RatioConfigurator {
    c.f.Schema("minimum", 0).Schema("maximum", 100)
    c.f.CheckMsg(func(v Ratio) bool { return v >= 0 && v <= 100 }, shared.M("ratio.percent", percentKey))
    return c
}