Package validator implements value validations for structs and individual fields based on tags.
It has the following unique features:
- Cross Field and Cross Struct validations by using validation tags or custom validators.
- Slice, Array and Map diving, which allows any or all levels of a multidimensional field to be validated.
- Ability to dive into both map keys and values for validation
- Handles type interface by determining it's underlying type prior to validation.
- Handles custom field types such as sql driver Valuer see Valuer
- Alias validation tags, which allows for mapping of several validations to a single tag for easier defining of validations on structs
- Extraction of custom defined Field Name e.g. can specify to extract the JSON name while validating and have it available in the resulting FieldError
- Customizable i18n aware error messages.
- Default validator for the gin web framework; upgrading from v8 to v9 in gin see here
Use go get.
go get github.com/go-playground/validator/v10
Then import the validator package into your own code.
import "github.com/go-playground/validator/v10"
Validation functions return type error
They return type error to avoid the issue discussed in the following, where err is always != nil:
Validator returns only InvalidValidationError for bad validation input, nil or ValidationErrors as type error; so, in your code all you need to do is check if the error returned is not nil, and if it's not check if error is InvalidValidationError ( if necessary, most of the time it isn't ) type cast it to type ValidationErrors like so:
err := validate.Struct(mystruct)
validationErrors := err.(validator.ValidationErrors)
Please see https://pkg.go.dev/github.com/go-playground/validator/v10 for detailed usage docs.
- Simple
- Custom Field Types
- Struct Level
- Translations & Custom Errors
- Gin upgrade and/or override validator
- wash - an example application putting it all together
- If new to using validator it is highly recommended to initialize it using the
WithRequiredStructEnabled
option which is opt-in to new behaviour that will become the default behaviour in v11+. See documentation for more details.
validate := validator.New(validator.WithRequiredStructEnabled())
Tag | Description |
---|---|
eqcsfield | Field Equals Another Field (relative) |
eqfield | Field Equals Another Field |
fieldcontains | Check the indicated characters are present in the Field |
fieldexcludes | Check the indicated characters are not present in the field |
gtcsfield | Field Greater Than Another Relative Field |
gtecsfield | Field Greater Than or Equal To Another Relative Field |
gtefield | Field Greater Than or Equal To Another Field |
gtfield | Field Greater Than Another Field |
ltcsfield | Less Than Another Relative Field |
ltecsfield | Less Than or Equal To Another Relative Field |
ltefield | Less Than or Equal To Another Field |
ltfield | Less Than Another Field |
necsfield | Field Does Not Equal Another Field (relative) |
nefield | Field Does Not Equal Another Field |
Tag | Description |
---|---|
cidr | Classless Inter-Domain Routing CIDR |
cidrv4 | Classless Inter-Domain Routing CIDRv4 |
cidrv6 | Classless Inter-Domain Routing CIDRv6 |
datauri | Data URL |
fqdn | Full Qualified Domain Name (FQDN) |
hostname | Hostname RFC 952 |
hostname_port | HostPort |
hostname_rfc1123 | Hostname RFC 1123 |
ip | Internet Protocol Address IP |
ip4_addr | Internet Protocol Address IPv4 |
ip6_addr | Internet Protocol Address IPv6 |
ip_addr | Internet Protocol Address IP |
ipv4 | Internet Protocol Address IPv4 |
ipv6 | Internet Protocol Address IPv6 |
mac | Media Access Control Address MAC |
tcp4_addr | Transmission Control Protocol Address TCPv4 |
tcp6_addr | Transmission Control Protocol Address TCPv6 |
tcp_addr | Transmission Control Protocol Address TCP |
udp4_addr | User Datagram Protocol Address UDPv4 |
udp6_addr | User Datagram Protocol Address UDPv6 |
udp_addr | User Datagram Protocol Address UDP |
unix_addr | Unix domain socket end point Address |
uri | URI String |
url | URL String |
http_url | HTTP URL String |
url_encoded | URL Encoded |
urn_rfc2141 | Urn RFC 2141 String |
Tag | Description |
---|---|
alpha | Alpha Only |
alphanum | Alphanumeric |
alphanumunicode | Alphanumeric Unicode |
alphaunicode | Alpha Unicode |
ascii | ASCII |
boolean | Boolean |
contains | Contains |
containsany | Contains Any |
containsrune | Contains Rune |
endsnotwith | Ends Not With |
endswith | Ends With |
excludes | Excludes |
excludesall | Excludes All |
excludesrune | Excludes Rune |
lowercase | Lowercase |
multibyte | Multi-Byte Characters |
number | Number |
numeric | Numeric |
printascii | Printable ASCII |
startsnotwith | Starts Not With |
startswith | Starts With |
uppercase | Uppercase |
Tag | Description |
---|---|
base64 | Base64 String |
base64url | Base64URL String |
base64rawurl | Base64RawURL String |
bic | Business Identifier Code (ISO 9362) |
bcp47_language_tag | Language tag (BCP 47) |
btc_addr | Bitcoin Address |
btc_addr_bech32 | Bitcoin Bech32 Address (segwit) |
credit_card | Credit Card Number |
mongodb | MongoDB ObjectID |
cron | Cron |
spicedb | SpiceDb ObjectID/Permission/Type |
datetime | Datetime |
e164 | e164 formatted phone number |
E-mail String | |
eth_addr | Ethereum Address |
hexadecimal | Hexadecimal String |
hexcolor | Hexcolor String |
hsl | HSL String |
hsla | HSLA String |
html | HTML Tags |
html_encoded | HTML Encoded |
isbn | International Standard Book Number |
isbn10 | International Standard Book Number 10 |
isbn13 | International Standard Book Number 13 |
issn | International Standard Serial Number |
iso3166_1_alpha2 | Two-letter country code (ISO 3166-1 alpha-2) |
iso3166_1_alpha3 | Three-letter country code (ISO 3166-1 alpha-3) |
iso3166_1_alpha_numeric | Numeric country code (ISO 3166-1 numeric) |
iso3166_2 | Country subdivision code (ISO 3166-2) |
iso4217 | Currency code (ISO 4217) |
json | JSON |
jwt | JSON Web Token (JWT) |
latitude | Latitude |
longitude | Longitude |
luhn_checksum | Luhn Algorithm Checksum (for strings and (u)int) |
postcode_iso3166_alpha2 | Postcode |
postcode_iso3166_alpha2_field | Postcode |
rgb | RGB String |
rgba | RGBA String |
ssn | Social Security Number SSN |
timezone | Timezone |
uuid | Universally Unique Identifier UUID |
uuid3 | Universally Unique Identifier UUID v3 |
uuid3_rfc4122 | Universally Unique Identifier UUID v3 RFC4122 |
uuid4 | Universally Unique Identifier UUID v4 |
uuid4_rfc4122 | Universally Unique Identifier UUID v4 RFC4122 |
uuid5 | Universally Unique Identifier UUID v5 |
uuid5_rfc4122 | Universally Unique Identifier UUID v5 RFC4122 |
uuid_rfc4122 | Universally Unique Identifier UUID RFC4122 |
md4 | MD4 hash |
md5 | MD5 hash |
sha256 | SHA256 hash |
sha384 | SHA384 hash |
sha512 | SHA512 hash |
ripemd128 | RIPEMD-128 hash |
ripemd128 | RIPEMD-160 hash |
tiger128 | TIGER128 hash |
tiger160 | TIGER160 hash |
tiger192 | TIGER192 hash |
semver | Semantic Versioning 2.0.0 |
ulid | Universally Unique Lexicographically Sortable Identifier ULID |
cve | Common Vulnerabilities and Exposures Identifier (CVE id) |
Tag | Description |
---|---|
eq | Equals |
eq_ignore_case | Equals ignoring case |
gt | Greater than |
gte | Greater than or equal |
lt | Less Than |
lte | Less Than or Equal |
ne | Not Equal |
ne_ignore_case | Not Equal ignoring case |
Tag | Description |
---|---|
dir | Existing Directory |
dirpath | Directory Path |
file | Existing File |
filepath | File Path |
image | Image |
isdefault | Is Default |
len | Length |
max | Maximum |
min | Minimum |
oneof | One Of |
required | Required |
required_if | Required If |
required_if_contains | Required If Contains |
required_unless | Required Unless |
required_with | Required With |
required_with_all | Required With All |
required_without | Required Without |
required_without_all | Required Without All |
excluded_if | Excluded If |
excluded_if_contains | Excluded If Contains |
excluded_unless | Excluded Unless |
excluded_unless_contains | Excluded Unless Contains |
excluded_with | Excluded With |
excluded_with_all | Excluded With All |
excluded_without | Excluded Without |
excluded_without_all | Excluded Without All |
unique | Unique |
Tag | Description |
---|---|
iscolor | hexcolor|rgb|rgba|hsl|hsla |
country_code | iso3166_1_alpha2|iso3166_1_alpha3|iso3166_1_alpha_numeric |
go version go1.21.0 darwin/arm64
goos: darwin
goarch: arm64
pkg: github.com/go-playground/validator/v10
BenchmarkFieldSuccess-8 33142266 35.94 ns/op 0 B/op 0 allocs/op
BenchmarkFieldSuccessParallel-8 200816191 6.568 ns/op 0 B/op 0 allocs/op
BenchmarkFieldFailure-8 6779707 175.1 ns/op 200 B/op 4 allocs/op
BenchmarkFieldFailureParallel-8 11044147 108.4 ns/op 200 B/op 4 allocs/op
BenchmarkFieldArrayDiveSuccess-8 6054232 194.4 ns/op 97 B/op 5 allocs/op
BenchmarkFieldArrayDiveSuccessParallel-8 12523388 94.07 ns/op 97 B/op 5 allocs/op
BenchmarkFieldArrayDiveFailure-8 3587043 334.3 ns/op 300 B/op 10 allocs/op
BenchmarkFieldArrayDiveFailureParallel-8 5816665 200.8 ns/op 300 B/op 10 allocs/op
BenchmarkFieldMapDiveSuccess-8 2217910 540.1 ns/op 288 B/op 14 allocs/op
BenchmarkFieldMapDiveSuccessParallel-8 4446698 258.7 ns/op 288 B/op 14 allocs/op
BenchmarkFieldMapDiveFailure-8 2392759 504.6 ns/op 376 B/op 13 allocs/op
BenchmarkFieldMapDiveFailureParallel-8 4244199 286.9 ns/op 376 B/op 13 allocs/op
BenchmarkFieldMapDiveWithKeysSuccess-8 2005857 592.1 ns/op 288 B/op 14 allocs/op
BenchmarkFieldMapDiveWithKeysSuccessParallel-8 4400850 296.9 ns/op 288 B/op 14 allocs/op
BenchmarkFieldMapDiveWithKeysFailure-8 1850227 643.8 ns/op 553 B/op 16 allocs/op
BenchmarkFieldMapDiveWithKeysFailureParallel-8 3293233 375.1 ns/op 553 B/op 16 allocs/op
BenchmarkFieldCustomTypeSuccess-8 12174412 98.25 ns/op 32 B/op 2 allocs/op
BenchmarkFieldCustomTypeSuccessParallel-8 34389907 35.49 ns/op 32 B/op 2 allocs/op
BenchmarkFieldCustomTypeFailure-8 7582524 156.6 ns/op 184 B/op 3 allocs/op
BenchmarkFieldCustomTypeFailureParallel-8 13019902 92.79 ns/op 184 B/op 3 allocs/op
BenchmarkFieldOrTagSuccess-8 3427260 349.4 ns/op 16 B/op 1 allocs/op
BenchmarkFieldOrTagSuccessParallel-8 15144128 81.25 ns/op 16 B/op 1 allocs/op
BenchmarkFieldOrTagFailure-8 5913546 201.9 ns/op 216 B/op 5 allocs/op
BenchmarkFieldOrTagFailureParallel-8 9810212 113.7 ns/op 216 B/op 5 allocs/op
BenchmarkStructLevelValidationSuccess-8 13456327 87.66 ns/op 16 B/op 1 allocs/op
BenchmarkStructLevelValidationSuccessParallel-8 41818888 27.77 ns/op 16 B/op 1 allocs/op
BenchmarkStructLevelValidationFailure-8 4166284 272.6 ns/op 264 B/op 7 allocs/op
BenchmarkStructLevelValidationFailureParallel-8 7594581 152.1 ns/op 264 B/op 7 allocs/op
BenchmarkStructSimpleCustomTypeSuccess-8 6508082 182.6 ns/op 32 B/op 2 allocs/op
BenchmarkStructSimpleCustomTypeSuccessParallel-8 23078605 54.78 ns/op 32 B/op 2 allocs/op
BenchmarkStructSimpleCustomTypeFailure-8 3118352 381.0 ns/op 416 B/op 9 allocs/op
BenchmarkStructSimpleCustomTypeFailureParallel-8 5300738 224.1 ns/op 432 B/op 10 allocs/op
BenchmarkStructFilteredSuccess-8 4761807 251.1 ns/op 216 B/op 5 allocs/op
BenchmarkStructFilteredSuccessParallel-8 8792598 128.6 ns/op 216 B/op 5 allocs/op
BenchmarkStructFilteredFailure-8 5202573 232.1 ns/op 216 B/op 5 allocs/op
BenchmarkStructFilteredFailureParallel-8 9591267 121.4 ns/op 216 B/op 5 allocs/op
BenchmarkStructPartialSuccess-8 5188512 231.6 ns/op 224 B/op 4 allocs/op
BenchmarkStructPartialSuccessParallel-8 9179776 123.1 ns/op 224 B/op 4 allocs/op
BenchmarkStructPartialFailure-8 3071212 392.5 ns/op 440 B/op 9 allocs/op
BenchmarkStructPartialFailureParallel-8 5344261 223.7 ns/op 440 B/op 9 allocs/op
BenchmarkStructExceptSuccess-8 3184230 375.0 ns/op 424 B/op 8 allocs/op
BenchmarkStructExceptSuccessParallel-8 10090130 108.9 ns/op 208 B/op 3 allocs/op
BenchmarkStructExceptFailure-8 3347226 357.7 ns/op 424 B/op 8 allocs/op
BenchmarkStructExceptFailureParallel-8 5654923 209.5 ns/op 424 B/op 8 allocs/op
BenchmarkStructSimpleCrossFieldSuccess-8 5232265 229.1 ns/op 56 B/op 3 allocs/op
BenchmarkStructSimpleCrossFieldSuccessParallel-8 17436674 64.75 ns/op 56 B/op 3 allocs/op
BenchmarkStructSimpleCrossFieldFailure-8 3128613 383.6 ns/op 272 B/op 8 allocs/op
BenchmarkStructSimpleCrossFieldFailureParallel-8 6994113 168.8 ns/op 272 B/op 8 allocs/op
BenchmarkStructSimpleCrossStructCrossFieldSuccess-8 3506487 340.9 ns/op 64 B/op 4 allocs/op
BenchmarkStructSimpleCrossStructCrossFieldSuccessParallel-8 13431300 91.77 ns/op 64 B/op 4 allocs/op
BenchmarkStructSimpleCrossStructCrossFieldFailure-8 2410566 500.9 ns/op 288 B/op 9 allocs/op
BenchmarkStructSimpleCrossStructCrossFieldFailureParallel-8 6344510 188.2 ns/op 288 B/op 9 allocs/op
BenchmarkStructSimpleSuccess-8 8922726 133.8 ns/op 0 B/op 0 allocs/op
BenchmarkStructSimpleSuccessParallel-8 55291153 23.63 ns/op 0 B/op 0 allocs/op
BenchmarkStructSimpleFailure-8 3171553 378.4 ns/op 416 B/op 9 allocs/op
BenchmarkStructSimpleFailureParallel-8 5571692 212.0 ns/op 416 B/op 9 allocs/op
BenchmarkStructComplexSuccess-8 1683750 714.5 ns/op 224 B/op 5 allocs/op
BenchmarkStructComplexSuccessParallel-8 4578046 257.0 ns/op 224 B/op 5 allocs/op
BenchmarkStructComplexFailure-8 481585 2547 ns/op 3041 B/op 48 allocs/op
BenchmarkStructComplexFailureParallel-8 965764 1577 ns/op 3040 B/op 48 allocs/op
BenchmarkOneof-8 17380881 68.50 ns/op 0 B/op 0 allocs/op
BenchmarkOneofParallel-8 8084733 153.5 ns/op 0 B/op 0 allocs/op
Here is a list of software that complements using this library either pre or post validation.
- form - Decodes url.Values into Go value(s) and Encodes Go value(s) into url.Values. Dual Array and Full map support.
- mold - A general library to help modify or set data within data structures and other objects
Make a pull request...
Distributed under MIT License, please see license file within the code for more details.
This project has grown large enough that more than one person is required to properly support the community. If you are interested in becoming a maintainer please reach out to me https://github.com/deankarn