Package validator
=================
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[](https://travis-ci.org/go-playground/validator)
[](https://coveralls.io/github/go-playground/validator?branch=master)
[](https://goreportcard.com/report/github.com/go-playground/validator)
[](https://pkg.go.dev/github.com/go-playground/validator/v10)
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 ](https://golang.org/src/database/sql/driver/types.go?s=1210:1293#L29 )
- 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 ](https://github.com/gin-gonic/gin ) web framework; upgrading from v8 to v9 in gin see [here ](https://github.com/go-playground/validator/tree/master/_examples/gin-upgrading-overriding )
Installation
------------
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"
Error Return Value
-------
Validation functions return type error
They return type error to avoid the issue discussed in the following, where err is always != nil:
* http://stackoverflow.com/a/29138676/3158232
* https://github.com/go-playground/validator/issues/134
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:
```go
err := validate.Struct(mystruct)
validationErrors := err.(validator.ValidationErrors)
```
Usage and documentation
------
Please see https://pkg.go.dev/github.com/go-playground/validator/v10 for detailed usage docs.
##### Examples:
- [Simple ](https://github.com/go-playground/validator/blob/master/_examples/simple/main.go )
- [Custom Field Types ](https://github.com/go-playground/validator/blob/master/_examples/custom/main.go )
- [Struct Level ](https://github.com/go-playground/validator/blob/master/_examples/struct-level/main.go )
- [Translations & Custom Errors ](https://github.com/go-playground/validator/blob/master/_examples/translations/main.go )
- [Gin upgrade and/or override validator ](https://github.com/go-playground/validator/tree/v9/_examples/gin-upgrading-overriding )
- [wash - an example application putting it all together ](https://github.com/bluesuncorp/wash )
Baked-in Validations
------
### Fields:
| Tag | Description |
| - | - |
| eqcsfield | Field Equals Another Field (relative)|
| eqfield | Field Equals Another Field |
| fieldcontains | NOT DOCUMENTED IN doc.go |
| fieldexcludes | NOT DOCUMENTED IN doc.go |
| 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 |
### Network:
| 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 |
| url_encoded | URL Encoded |
| urn_rfc2141 | Urn RFC 2141 String |
### Strings:
| 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 | NOT DOCUMENTED IN doc.go |
| numeric | Numeric |
| printascii | Printable ASCII |
| startsnotwith | Starts Not With |
| startswith | Starts With |
| uppercase | Uppercase |
### Format:
| Tag | Description |
| - | - |
| base64 | Base64 String |
| base64url | Base64URL 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 |
| datetime | Datetime |
| e164 | e164 formatted phone number |
| email | 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 |
| 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 |
| 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 |
| semver | Semantic Versioning 2.0.0 |
| ulid | Universally Unique Lexicographically Sortable Identifier ULID |
### Comparisons:
| Tag | Description |
| - | - |
| eq | Equals |
| gt | Greater than|
| gte | Greater than or equal |
| lt | Less Than |
| lte | Less Than or Equal |
| ne | Not Equal |
### Other:
| Tag | Description |
| - | - |
| dir | Directory |
| file | File path |
| isdefault | Is Default |
| len | Length |
| max | Maximum |
| min | Minimum |
| oneof | One Of |
| required | Required |
| required_if | Required If |
| 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_unless | Excluded Unless |
| excluded_with | Excluded With |
| excluded_with_all | Excluded With All |
| excluded_without | Excluded Without |
| excluded_without_all | Excluded Without All |
| unique | Unique |
#### Aliases:
| Tag | Description |
| - | - |
| iscolor | hexcolor\|rgb\|rgba\|hsl\|hsla |
| country_code | iso3166_1_alpha2\|iso3166_1_alpha3\|iso3166_1_alpha_numeric |
Benchmarks
------
###### Run on MacBook Pro (15-inch, 2017) go version go1.10.2 darwin/amd64
```go
goos: darwin
goarch: amd64
pkg: github.com/go-playground/validator
BenchmarkFieldSuccess-8 20000000 83.6 ns/op 0 B/op 0 allocs/op
BenchmarkFieldSuccessParallel-8 50000000 26.8 ns/op 0 B/op 0 allocs/op
BenchmarkFieldFailure-8 5000000 291 ns/op 208 B/op 4 allocs/op
BenchmarkFieldFailureParallel-8 20000000 107 ns/op 208 B/op 4 allocs/op
BenchmarkFieldArrayDiveSuccess-8 2000000 623 ns/op 201 B/op 11 allocs/op
BenchmarkFieldArrayDiveSuccessParallel-8 10000000 237 ns/op 201 B/op 11 allocs/op
BenchmarkFieldArrayDiveFailure-8 2000000 859 ns/op 412 B/op 16 allocs/op
BenchmarkFieldArrayDiveFailureParallel-8 5000000 335 ns/op 413 B/op 16 allocs/op
BenchmarkFieldMapDiveSuccess-8 1000000 1292 ns/op 432 B/op 18 allocs/op
BenchmarkFieldMapDiveSuccessParallel-8 3000000 467 ns/op 432 B/op 18 allocs/op
BenchmarkFieldMapDiveFailure-8 1000000 1082 ns/op 512 B/op 16 allocs/op
BenchmarkFieldMapDiveFailureParallel-8 5000000 425 ns/op 512 B/op 16 allocs/op
BenchmarkFieldMapDiveWithKeysSuccess-8 1000000 1539 ns/op 480 B/op 21 allocs/op
BenchmarkFieldMapDiveWithKeysSuccessParallel-8 3000000 613 ns/op 480 B/op 21 allocs/op
BenchmarkFieldMapDiveWithKeysFailure-8 1000000 1413 ns/op 721 B/op 21 allocs/op
BenchmarkFieldMapDiveWithKeysFailureParallel-8 3000000 575 ns/op 721 B/op 21 allocs/op
BenchmarkFieldCustomTypeSuccess-8 10000000 216 ns/op 32 B/op 2 allocs/op
BenchmarkFieldCustomTypeSuccessParallel-8 20000000 82.2 ns/op 32 B/op 2 allocs/op
BenchmarkFieldCustomTypeFailure-8 5000000 274 ns/op 208 B/op 4 allocs/op
BenchmarkFieldCustomTypeFailureParallel-8 20000000 116 ns/op 208 B/op 4 allocs/op
BenchmarkFieldOrTagSuccess-8 2000000 740 ns/op 16 B/op 1 allocs/op
BenchmarkFieldOrTagSuccessParallel-8 3000000 474 ns/op 16 B/op 1 allocs/op
BenchmarkFieldOrTagFailure-8 3000000 471 ns/op 224 B/op 5 allocs/op
BenchmarkFieldOrTagFailureParallel-8 3000000 414 ns/op 224 B/op 5 allocs/op
BenchmarkStructLevelValidationSuccess-8 10000000 213 ns/op 32 B/op 2 allocs/op
BenchmarkStructLevelValidationSuccessParallel-8 20000000 91.8 ns/op 32 B/op 2 allocs/op
BenchmarkStructLevelValidationFailure-8 3000000 473 ns/op 304 B/op 8 allocs/op
BenchmarkStructLevelValidationFailureParallel-8 10000000 234 ns/op 304 B/op 8 allocs/op
BenchmarkStructSimpleCustomTypeSuccess-8 5000000 385 ns/op 32 B/op 2 allocs/op
BenchmarkStructSimpleCustomTypeSuccessParallel-8 10000000 161 ns/op 32 B/op 2 allocs/op
BenchmarkStructSimpleCustomTypeFailure-8 2000000 640 ns/op 424 B/op 9 allocs/op
BenchmarkStructSimpleCustomTypeFailureParallel-8 5000000 318 ns/op 440 B/op 10 allocs/op
BenchmarkStructFilteredSuccess-8 2000000 597 ns/op 288 B/op 9 allocs/op
BenchmarkStructFilteredSuccessParallel-8 10000000 266 ns/op 288 B/op 9 allocs/op
BenchmarkStructFilteredFailure-8 3000000 454 ns/op 256 B/op 7 allocs/op
BenchmarkStructFilteredFailureParallel-8 10000000 214 ns/op 256 B/op 7 allocs/op
BenchmarkStructPartialSuccess-8 3000000 502 ns/op 256 B/op 6 allocs/op
BenchmarkStructPartialSuccessParallel-8 10000000 225 ns/op 256 B/op 6 allocs/op
BenchmarkStructPartialFailure-8 2000000 702 ns/op 480 B/op 11 allocs/op
BenchmarkStructPartialFailureParallel-8 5000000 329 ns/op 480 B/op 11 allocs/op
BenchmarkStructExceptSuccess-8 2000000 793 ns/op 496 B/op 12 allocs/op
BenchmarkStructExceptSuccessParallel-8 10000000 193 ns/op 240 B/op 5 allocs/op
BenchmarkStructExceptFailure-8 2000000 639 ns/op 464 B/op 10 allocs/op
BenchmarkStructExceptFailureParallel-8 5000000 300 ns/op 464 B/op 10 allocs/op
BenchmarkStructSimpleCrossFieldSuccess-8 3000000 417 ns/op 72 B/op 3 allocs/op
BenchmarkStructSimpleCrossFieldSuccessParallel-8 10000000 163 ns/op 72 B/op 3 allocs/op
BenchmarkStructSimpleCrossFieldFailure-8 2000000 645 ns/op 304 B/op 8 allocs/op
BenchmarkStructSimpleCrossFieldFailureParallel-8 5000000 285 ns/op 304 B/op 8 allocs/op
BenchmarkStructSimpleCrossStructCrossFieldSuccess-8 3000000 588 ns/op 80 B/op 4 allocs/op
BenchmarkStructSimpleCrossStructCrossFieldSuccessParallel-8 10000000 221 ns/op 80 B/op 4 allocs/op
BenchmarkStructSimpleCrossStructCrossFieldFailure-8 2000000 868 ns/op 320 B/op 9 allocs/op
BenchmarkStructSimpleCrossStructCrossFieldFailureParallel-8 5000000 337 ns/op 320 B/op 9 allocs/op
BenchmarkStructSimpleSuccess-8 5000000 260 ns/op 0 B/op 0 allocs/op
BenchmarkStructSimpleSuccessParallel-8 20000000 90.6 ns/op 0 B/op 0 allocs/op
BenchmarkStructSimpleFailure-8 2000000 619 ns/op 424 B/op 9 allocs/op
BenchmarkStructSimpleFailureParallel-8 5000000 296 ns/op 424 B/op 9 allocs/op
BenchmarkStructComplexSuccess-8 1000000 1454 ns/op 128 B/op 8 allocs/op
BenchmarkStructComplexSuccessParallel-8 3000000 579 ns/op 128 B/op 8 allocs/op
BenchmarkStructComplexFailure-8 300000 4140 ns/op 3041 B/op 53 allocs/op
BenchmarkStructComplexFailureParallel-8 1000000 2127 ns/op 3041 B/op 53 allocs/op
BenchmarkOneof-8 10000000 140 ns/op 0 B/op 0 allocs/op
BenchmarkOneofParallel-8 20000000 70.1 ns/op 0 B/op 0 allocs/op
```
Complementary Software
----------------------
Here is a list of software that complements using this library either pre or post validation.
* [form ](https://github.com/go-playground/form ) - Decodes url.Values into Go value(s) and Encodes Go value(s) into url.Values. Dual Array and Full map support.
* [mold ](https://github.com/go-playground/mold ) - A general library to help modify or set data within data structures and other objects
How to Contribute
------
Make a pull request...
License
-------
Distributed under MIT License, please see license file within the code for more details.
Maintainers
-----------
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
