validator

package module

v10.2.0 Latest Latest Go to latest Published: Feb 9, 2020 License: MIT Imports: 19 Imported by: 11,889

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Repository

github.com/go-playground/validator

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Open Source Insights

README ¶

Package validator

License

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

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:

Validator 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)

Usage and documentation

Please see https://godoc.org/github.com/go-playground/validator for detailed usage docs.

Examples:

Benchmarks

Run on MacBook Pro (15-inch, 2017) go version go1.10.2 darwin/amd64

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 - 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

How to Contribute

Make a pull request...

License

Distributed under MIT License, please see license file within the code for more details.

Documentation ¶

Overview ¶

Package validator implements value validations for structs and individual fields based on tags.

It can also handle Cross-Field and Cross-Struct validation for nested structs and has the ability to dive into arrays and maps of any type.

see more examples https://github.com/go-playground/validator/tree/master/_examples

Validation Functions Return Type error ¶

Doing things this way is actually the way the standard library does, see the file.Open method here:

https://golang.org/pkg/os/#Open.

The authors 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 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.(validator.ValidationErrors).

Custom Validation Functions ¶

Custom Validation functions can be added. Example:

// Structure
func customFunc(fl validator.FieldLevel) bool {

	if fl.Field().String() == "invalid" {
		return false
	}

	return true
}

validate.RegisterValidation("custom tag name", customFunc)
// NOTES: using the same tag name as an existing function
//        will overwrite the existing one

Cross-Field Validation ¶

Cross-Field Validation can be done via the following tags:

eqfield
nefield
gtfield
gtefield
ltfield
ltefield
eqcsfield
necsfield
gtcsfield
gtecsfield
ltcsfield
ltecsfield

If, however, some custom cross-field validation is required, it can be done using a custom validation.

Why not just have cross-fields validation tags (i.e. only eqcsfield and not eqfield)?

The reason is efficiency. If you want to check a field within the same struct "eqfield" only has to find the field on the same struct (1 level). But, if we used "eqcsfield" it could be multiple levels down. Example:

type Inner struct {
	StartDate time.Time
}

type Outer struct {
	InnerStructField *Inner
	CreatedAt time.Time      `validate:"ltecsfield=InnerStructField.StartDate"`
}

now := time.Now()

inner := &Inner{
	StartDate: now,
}

outer := &Outer{
	InnerStructField: inner,
	CreatedAt: now,
}

errs := validate.Struct(outer)

// NOTE: when calling validate.Struct(val) topStruct will be the top level struct passed
//       into the function
//       when calling validate.VarWithValue(val, field, tag) val will be
//       whatever you pass, struct, field...
//       when calling validate.Field(field, tag) val will be nil

Multiple Validators ¶

Multiple validators on a field will process in the order defined. Example:

type Test struct {
	Field `validate:"max=10,min=1"`
}

// max will be checked then min

Bad Validator definitions are not handled by the library. Example:

type Test struct {
	Field `validate:"min=10,max=0"`
}

// this definition of min max will never succeed

Using Validator Tags ¶

Baked In Cross-Field validation only compares fields on the same struct. If Cross-Field + Cross-Struct validation is needed you should implement your own custom validator.

Comma (",") is the default separator of validation tags. If you wish to have a comma included within the parameter (i.e. excludesall=,) you will need to use the UTF-8 hex representation 0x2C, which is replaced in the code as a comma, so the above will become excludesall=0x2C.

type Test struct {
	Field `validate:"excludesall=,"`    // BAD! Do not include a comma.
	Field `validate:"excludesall=0x2C"` // GOOD! Use the UTF-8 hex representation.
}

Pipe ("|") is the 'or' validation tags deparator. If you wish to have a pipe included within the parameter i.e. excludesall=| you will need to use the UTF-8 hex representation 0x7C, which is replaced in the code as a pipe, so the above will become excludesall=0x7C

type Test struct {
	Field `validate:"excludesall=|"`    // BAD! Do not include a a pipe!
	Field `validate:"excludesall=0x7C"` // GOOD! Use the UTF-8 hex representation.
}

Baked In Validators and Tags ¶

Here is a list of the current built in validators:

Skip Field ¶

Tells the validation to skip this struct field; this is particularly handy in ignoring embedded structs from being validated. (Usage: -)

Usage: -

Or Operator ¶

This is the 'or' operator allowing multiple validators to be used and accepted. (Usage: rgb|rgba) <-- this would allow either rgb or rgba colors to be accepted. This can also be combined with 'and' for example ( Usage: omitempty,rgb|rgba)

Usage: |

StructOnly ¶

When a field that is a nested struct is encountered, and contains this flag any validation on the nested struct will be run, but none of the nested struct fields will be validated. This is useful if inside of your program you know the struct will be valid, but need to verify it has been assigned. NOTE: only "required" and "omitempty" can be used on a struct itself.

Usage: structonly

NoStructLevel ¶

Same as structonly tag except that any struct level validations will not run.

Usage: nostructlevel

Omit Empty ¶

Allows conditional validation, for example if a field is not set with a value (Determined by the "required" validator) then other validation such as min or max won't run, but if a value is set validation will run.

Usage: omitempty

Dive ¶

This tells the validator to dive into a slice, array or map and validate that level of the slice, array or map with the validation tags that follow. Multidimensional nesting is also supported, each level you wish to dive will require another dive tag. dive has some sub-tags, 'keys' & 'endkeys', please see the Keys & EndKeys section just below.

Usage: dive

Example #1

[][]string with validation tag "gt=0,dive,len=1,dive,required"
// gt=0 will be applied to []
// len=1 will be applied to []string
// required will be applied to string

Example #2

[][]string with validation tag "gt=0,dive,dive,required"
// gt=0 will be applied to []
// []string will be spared validation
// required will be applied to string

Keys & EndKeys

These are to be used together directly after the dive tag and tells the validator that anything between 'keys' and 'endkeys' applies to the keys of a map and not the values; think of it like the 'dive' tag, but for map keys instead of values. Multidimensional nesting is also supported, each level you wish to validate will require another 'keys' and 'endkeys' tag. These tags are only valid for maps.

Usage: dive,keys,othertagvalidation(s),endkeys,valuevalidationtags

Example #1

map[string]string with validation tag "gt=0,dive,keys,eg=1|eq=2,endkeys,required"
// gt=0 will be applied to the map itself
// eg=1|eq=2 will be applied to the map keys
// required will be applied to map values

Example #2

map[[2]string]string with validation tag "gt=0,dive,keys,dive,eq=1|eq=2,endkeys,required"
// gt=0 will be applied to the map itself
// eg=1|eq=2 will be applied to each array element in the the map keys
// required will be applied to map values

Required ¶

This validates that the value is not the data types default zero value. For numbers ensures value is not zero. For strings ensures value is not "". For slices, maps, pointers, interfaces, channels and functions ensures the value is not nil.

Usage: required

Required With ¶

The field under validation must be present and not empty only if any of the other specified fields are present. For strings ensures value is not "". For slices, maps, pointers, interfaces, channels and functions ensures the value is not nil.

Usage: required_with

Examples:

// require the field if the Field1 is present:
Usage: required_with=Field1

// require the field if the Field1 or Field2 is present:
Usage: required_with=Field1 Field2

Required With All ¶

The field under validation must be present and not empty only if all of the other specified fields are present. For strings ensures value is not "". For slices, maps, pointers, interfaces, channels and functions ensures the value is not nil.

Usage: required_with_all

Example:

// require the field if the Field1 and Field2 is present:
Usage: required_with_all=Field1 Field2

Required Without ¶

The field under validation must be present and not empty only when any of the other specified fields are not present. For strings ensures value is not "". For slices, maps, pointers, interfaces, channels and functions ensures the value is not nil.

Usage: required_without

Examples:

// require the field if the Field1 is not present:
Usage: required_without=Field1

// require the field if the Field1 or Field2 is not present:
Usage: required_without=Field1 Field2

Required Without All ¶

The field under validation must be present and not empty only when all of the other specified fields are not present. For strings ensures value is not "". For slices, maps, pointers, interfaces, channels and functions ensures the value is not nil.

Usage: required_without_all

Example:

// require the field if the Field1 and Field2 is not present:
Usage: required_without_all=Field1 Field2

Is Default ¶

This validates that the value is the default value and is almost the opposite of required.

Usage: isdefault

Length ¶

For numbers, length will ensure that the value is equal to the parameter given. For strings, it checks that the string length is exactly that number of characters. For slices, arrays, and maps, validates the number of items.

Usage: len=10

Maximum ¶

For numbers, max will ensure that the value is less than or equal to the parameter given. For strings, it checks that the string length is at most that number of characters. For slices, arrays, and maps, validates the number of items.

Usage: max=10

Minimum ¶

For numbers, min will ensure that the value is greater or equal to the parameter given. For strings, it checks that the string length is at least that number of characters. For slices, arrays, and maps, validates the number of items.

Usage: min=10

Equals ¶

For strings & numbers, eq will ensure that the value is equal to the parameter given. For slices, arrays, and maps, validates the number of items.

Usage: eq=10

Not Equal ¶

For strings & numbers, ne will ensure that the value is not equal to the parameter given. For slices, arrays, and maps, validates the number of items.

Usage: ne=10

One Of ¶

For strings, ints, and uints, oneof will ensure that the value is one of the values in the parameter. The parameter should be a list of values separated by whitespace. Values may be strings or numbers. To match strings with spaces in them, include the target string between single quotes.

Usage: oneof=red green
       oneof='red green' 'blue yellow'
       oneof=5 7 9

Greater Than ¶

For numbers, this will ensure that the value is greater than the parameter given. For strings, it checks that the string length is greater than that number of characters. For slices, arrays and maps it validates the number of items.

Example #1

Usage: gt=10

Example #2 (time.Time)

For time.Time ensures the time value is greater than time.Now.UTC().

Usage: gt

Greater Than or Equal ¶

Same as 'min' above. Kept both to make terminology with 'len' easier.

Example #1

Usage: gte=10

Example #2 (time.Time)

For time.Time ensures the time value is greater than or equal to time.Now.UTC().

Usage: gte

Less Than ¶

For numbers, this will ensure that the value is less than the parameter given. For strings, it checks that the string length is less than that number of characters. For slices, arrays, and maps it validates the number of items.

Example #1

Usage: lt=10

Example #2 (time.Time) For time.Time ensures the time value is less than time.Now.UTC().

Usage: lt

Less Than or Equal ¶

Same as 'max' above. Kept both to make terminology with 'len' easier.

Example #1

Usage: lte=10

Example #2 (time.Time)

For time.Time ensures the time value is less than or equal to time.Now.UTC().

Usage: lte

Field Equals Another Field ¶

This will validate the field value against another fields value either within a struct or passed in field.

Example #1:

// Validation on Password field using:
Usage: eqfield=ConfirmPassword

Example #2:

// Validating by field:
validate.VarWithValue(password, confirmpassword, "eqfield")

Field Equals Another Field (relative)

This does the same as eqfield except that it validates the field provided relative to the top level struct.

Usage: eqcsfield=InnerStructField.Field)

Field Does Not Equal Another Field ¶

This will validate the field value against another fields value either within a struct or passed in field.

Examples:

// Confirm two colors are not the same:
//
// Validation on Color field:
Usage: nefield=Color2

// Validating by field:
validate.VarWithValue(color1, color2, "nefield")

Field Does Not Equal Another Field (relative)

This does the same as nefield except that it validates the field provided relative to the top level struct.

Usage: necsfield=InnerStructField.Field

Field Greater Than Another Field ¶

Only valid for Numbers and time.Time types, this will validate the field value against another fields value either within a struct or passed in field. usage examples are for validation of a Start and End date:

Example #1:

// Validation on End field using:
validate.Struct Usage(gtfield=Start)

Example #2:

// Validating by field:
validate.VarWithValue(start, end, "gtfield")

Field Greater Than Another Relative Field ¶

This does the same as gtfield except that it validates the field provided relative to the top level struct.

Usage: gtcsfield=InnerStructField.Field

Field Greater Than or Equal To Another Field ¶

Only valid for Numbers and time.Time types, this will validate the field value against another fields value either within a struct or passed in field. usage examples are for validation of a Start and End date:

Example #1:

// Validation on End field using:
validate.Struct Usage(gtefield=Start)

Example #2:

// Validating by field:
validate.VarWithValue(start, end, "gtefield")

Field Greater Than or Equal To Another Relative Field ¶

This does the same as gtefield except that it validates the field provided relative to the top level struct.

Usage: gtecsfield=InnerStructField.Field

Less Than Another Field ¶

Only valid for Numbers and time.Time types, this will validate the field value against another fields value either within a struct or passed in field. usage examples are for validation of a Start and End date:

Example #1:

// Validation on End field using:
validate.Struct Usage(ltfield=Start)

Example #2:

// Validating by field:
validate.VarWithValue(start, end, "ltfield")

Less Than Another Relative Field ¶

This does the same as ltfield except that it validates the field provided relative to the top level struct.

Usage: ltcsfield=InnerStructField.Field

Less Than or Equal To Another Field ¶

Only valid for Numbers and time.Time types, this will validate the field value against another fields value either within a struct or passed in field. usage examples are for validation of a Start and End date:

Example #1:

// Validation on End field using:
validate.Struct Usage(ltefield=Start)

Example #2:

// Validating by field:
validate.VarWithValue(start, end, "ltefield")

Less Than or Equal To Another Relative Field ¶

This does the same as ltefield except that it validates the field provided relative to the top level struct.

Usage: ltecsfield=InnerStructField.Field

Field Contains Another Field ¶

This does the same as contains except for struct fields. It should only be used with string types. See the behavior of reflect.Value.String() for behavior on other types.

Usage: containsfield=InnerStructField.Field

Field Excludes Another Field ¶

This does the same as excludes except for struct fields. It should only be used with string types. See the behavior of reflect.Value.String() for behavior on other types.

Usage: excludesfield=InnerStructField.Field

Unique ¶

For arrays & slices, unique will ensure that there are no duplicates. For maps, unique will ensure that there are no duplicate values. For slices of struct, unique will ensure that there are no duplicate values in a field of the struct specified via a parameter.

// For arrays, slices, and maps:
Usage: unique

// For slices of struct:
Usage: unique=field

Alpha Only ¶

This validates that a string value contains ASCII alpha characters only

Usage: alpha

Alphanumeric ¶

This validates that a string value contains ASCII alphanumeric characters only

Usage: alphanum

Alpha Unicode ¶

This validates that a string value contains unicode alpha characters only

Usage: alphaunicode

Alphanumeric Unicode ¶

This validates that a string value contains unicode alphanumeric characters only

Usage: alphanumunicode

Numeric ¶

This validates that a string value contains a basic numeric value. basic excludes exponents etc... for integers or float it returns true.

Usage: numeric

Hexadecimal String ¶

This validates that a string value contains a valid hexadecimal.

Usage: hexadecimal

Hexcolor String ¶

This validates that a string value contains a valid hex color including hashtag (#)

Usage: hexcolor

Lowercase String ¶

This validates that a string value contains only lowercase characters. An empty string is not a valid lowercase string.

Usage: lowercase

Uppercase String ¶

This validates that a string value contains only uppercase characters. An empty string is not a valid uppercase string.

Usage: uppercase

RGB String ¶

This validates that a string value contains a valid rgb color

Usage: rgb

RGBA String ¶

This validates that a string value contains a valid rgba color

Usage: rgba

HSL String ¶

This validates that a string value contains a valid hsl color

Usage: hsl

HSLA String ¶

This validates that a string value contains a valid hsla color

Usage: hsla

E-mail String ¶

This validates that a string value contains a valid email This may not conform to all possibilities of any rfc standard, but neither does any email provider accept all possibilities.

Usage: email

JSON String ¶

This validates that a string value is valid JSON

Usage: json

File path ¶

This validates that a string value contains a valid file path and that the file exists on the machine. This is done using os.Stat, which is a platform independent function.

Usage: file

URL String ¶

This validates that a string value contains a valid url This will accept any url the golang request uri accepts but must contain a schema for example http:// or rtmp://

Usage: url

URI String ¶

This validates that a string value contains a valid uri This will accept any uri the golang request uri accepts

Usage: uri

Urn RFC 2141 String RFC 2141 String">¶

This validataes that a string value contains a valid URN according to the RFC 2141 spec.

Usage: urn_rfc2141

Base64 String ¶

This validates that a string value contains a valid base64 value. Although an empty string is valid base64 this will report an empty string as an error, if you wish to accept an empty string as valid you can use this with the omitempty tag.

Usage: base64

Base64URL String ¶

This validates that a string value contains a valid base64 URL safe value according the the RFC4648 spec. Although an empty string is a valid base64 URL safe value, this will report an empty string as an error, if you wish to accept an empty string as valid you can use this with the omitempty tag.

Usage: base64url

Bitcoin Address ¶

This validates that a string value contains a valid bitcoin address. The format of the string is checked to ensure it matches one of the three formats P2PKH, P2SH and performs checksum validation.

Usage: btc_addr

Bitcoin Bech32 Address (segwit)

This validates that a string value contains a valid bitcoin Bech32 address as defined by bip-0173 (https://github.com/bitcoin/bips/blob/master/bip-0173.mediawiki) Special thanks to Pieter Wuille for providng reference implementations.

Usage: btc_addr_bech32

Ethereum Address ¶

This validates that a string value contains a valid ethereum address. The format of the string is checked to ensure it matches the standard Ethereum address format Full validation is blocked by https://github.com/golang/crypto/pull/28

Usage: eth_addr

Contains ¶

This validates that a string value contains the substring value.

Usage: contains=@

Contains Any ¶

This validates that a string value contains any Unicode code points in the substring value.

Usage: containsany=!@#?

Contains Rune ¶

This validates that a string value contains the supplied rune value.

Usage: containsrune=@

Excludes ¶

This validates that a string value does not contain the substring value.

Usage: excludes=@

Excludes All ¶

This validates that a string value does not contain any Unicode code points in the substring value.

Usage: excludesall=!@#?

Excludes Rune ¶

This validates that a string value does not contain the supplied rune value.

Usage: excludesrune=@

Starts With ¶

This validates that a string value starts with the supplied string value

Usage: startswith=hello

Ends With ¶

This validates that a string value ends with the supplied string value

Usage: endswith=goodbye

International Standard Book Number ¶

This validates that a string value contains a valid isbn10 or isbn13 value.

Usage: isbn

International Standard Book Number 10 ¶

This validates that a string value contains a valid isbn10 value.

Usage: isbn10

International Standard Book Number 13 ¶

This validates that a string value contains a valid isbn13 value.

Usage: isbn13

Universally Unique Identifier UUID ¶

This validates that a string value contains a valid UUID. Uppercase UUID values will not pass - use `uuid_rfc4122` instead.

Usage: uuid

Universally Unique Identifier UUID v3 ¶

This validates that a string value contains a valid version 3 UUID. Uppercase UUID values will not pass - use `uuid3_rfc4122` instead.

Usage: uuid3

Universally Unique Identifier UUID v4 ¶

This validates that a string value contains a valid version 4 UUID. Uppercase UUID values will not pass - use `uuid4_rfc4122` instead.

Usage: uuid4

Universally Unique Identifier UUID v5 ¶

This validates that a string value contains a valid version 5 UUID. Uppercase UUID values will not pass - use `uuid5_rfc4122` instead.

Usage: uuid5

ASCII ¶

This validates that a string value contains only ASCII characters. NOTE: if the string is blank, this validates as true.

Usage: ascii

Printable ASCII ¶

This validates that a string value contains only printable ASCII characters. NOTE: if the string is blank, this validates as true.

Usage: printascii

Multi-Byte Characters ¶

This validates that a string value contains one or more multibyte characters. NOTE: if the string is blank, this validates as true.

Usage: multibyte

Data URL ¶

This validates that a string value contains a valid DataURI. NOTE: this will also validate that the data portion is valid base64

Usage: datauri

Latitude ¶

This validates that a string value contains a valid latitude.

Usage: latitude

Longitude ¶

This validates that a string value contains a valid longitude.

Usage: longitude

Social Security Number SSN ¶

This validates that a string value contains a valid U.S. Social Security Number.

Usage: ssn

Internet Protocol Address IP ¶

This validates that a string value contains a valid IP Address.

Usage: ip

Internet Protocol Address IPv4 ¶

This validates that a string value contains a valid v4 IP Address.

Usage: ipv4

Internet Protocol Address IPv6 ¶

This validates that a string value contains a valid v6 IP Address.

Usage: ipv6

Classless Inter-Domain Routing CIDR ¶

This validates that a string value contains a valid CIDR Address.

Usage: cidr

Classless Inter-Domain Routing CIDRv4 ¶

This validates that a string value contains a valid v4 CIDR Address.

Usage: cidrv4

Classless Inter-Domain Routing CIDRv6 ¶

This validates that a string value contains a valid v6 CIDR Address.

Usage: cidrv6

Transmission Control Protocol Address TCP ¶

This validates that a string value contains a valid resolvable TCP Address.

Usage: tcp_addr

Transmission Control Protocol Address TCPv4 ¶

This validates that a string value contains a valid resolvable v4 TCP Address.

Usage: tcp4_addr

Transmission Control Protocol Address TCPv6 ¶

This validates that a string value contains a valid resolvable v6 TCP Address.

Usage: tcp6_addr

User Datagram Protocol Address UDP ¶

This validates that a string value contains a valid resolvable UDP Address.

Usage: udp_addr

User Datagram Protocol Address UDPv4 ¶

This validates that a string value contains a valid resolvable v4 UDP Address.

Usage: udp4_addr

User Datagram Protocol Address UDPv6 ¶

This validates that a string value contains a valid resolvable v6 UDP Address.

Usage: udp6_addr

Internet Protocol Address IP ¶

This validates that a string value contains a valid resolvable IP Address.

Usage: ip_addr

Internet Protocol Address IPv4 ¶

This validates that a string value contains a valid resolvable v4 IP Address.

Usage: ip4_addr

Internet Protocol Address IPv6 ¶

This validates that a string value contains a valid resolvable v6 IP Address.

Usage: ip6_addr

Unix domain socket end point Address ¶

This validates that a string value contains a valid Unix Address.

Usage: unix_addr

Media Access Control Address MAC ¶

This validates that a string value contains a valid MAC Address.

Usage: mac

Note: See Go's ParseMAC for accepted formats and types:

http://golang.org/src/net/mac.go?s=866:918#L29

Hostname RFC 952 RFC 952">¶

This validates that a string value is a valid Hostname according to RFC 952 https://tools.ietf.org/html/rfc952

Usage: hostname

Hostname RFC 1123 RFC 1123">¶

This validates that a string value is a valid Hostname according to RFC 1123 https://tools.ietf.org/html/rfc1123

Usage: hostname_rfc1123 or if you want to continue to use 'hostname' in your tags, create an alias.

Full Qualified Domain Name (FQDN)

This validates that a string value contains a valid FQDN.

Usage: fqdn

HTML Tags ¶

This validates that a string value appears to be an HTML element tag including those described at https://developer.mozilla.org/en-US/docs/Web/HTML/Element

Usage: html

HTML Encoded ¶

This validates that a string value is a proper character reference in decimal or hexadecimal format

Usage: html_encoded

URL Encoded ¶

This validates that a string value is percent-encoded (URL encoded) according to https://tools.ietf.org/html/rfc3986#section-2.1

Usage: url_encoded

Directory ¶

This validates that a string value contains a valid directory and that it exists on the machine. This is done using os.Stat, which is a platform independent function.

Usage: dir

HostPort ¶

This validates that a string value contains a valid DNS hostname and port that can be used to valiate fields typically passed to sockets and connections.

Usage: hostname_port

Datetime ¶

This validates that a string value is a valid datetime based on the supplied datetime format. Supplied format must match the official Go time format layout as documented in https://golang.org/pkg/time/

Usage: datetime=2006-01-02

Alias Validators and Tags ¶

NOTE: When returning an error, the tag returned in "FieldError" will be the alias tag unless the dive tag is part of the alias. Everything after the dive tag is not reported as the alias tag. Also, the "ActualTag" in the before case will be the actual tag within the alias that failed.

Here is a list of the current built in alias tags:

"iscolor"
	alias is "hexcolor|rgb|rgba|hsl|hsla" (Usage: iscolor)

Validator notes:

regex
	a regex validator won't be added because commas and = signs can be part
	of a regex which conflict with the validation definitions. Although
	workarounds can be made, they take away from using pure regex's.
	Furthermore it's quick and dirty but the regex's become harder to
	maintain and are not reusable, so it's as much a programming philosophy
	as anything.

	In place of this new validator functions should be created; a regex can
	be used within the validator function and even be precompiled for better
	efficiency within regexes.go.

	And the best reason, you can submit a pull request and we can keep on
	adding to the validation library of this package!

Non standard validators ¶

A collection of validation rules that are frequently needed but are more complex than the ones found in the baked in validators. A non standard validator must be registered manually like you would with your own custom validation functions.

Example of registration and use:

type Test struct {
	TestField string `validate:"yourtag"`
}

t := &Test{
	TestField: "Test"
}

validate := validator.New()
validate.RegisterValidation("yourtag", validators.NotBlank)

Here is a list of the current non standard validators:

NotBlank
	This validates that the value is not blank or with length zero.
	For strings ensures they do not contain only spaces. For channels, maps, slices and arrays
	ensures they don't have zero length. For others, a non empty value is required.

	Usage: notblank

Panics ¶

This package panics when bad input is provided, this is by design, bad code like that should not make it to production.

type Test struct {
	TestField string `validate:"nonexistantfunction=1"`
}

t := &Test{
	TestField: "Test"
}

validate.Struct(t) // this will panic

Index ¶

type CustomTypeFunc
type FieldError
type FieldLevel
type FilterFunc
type Func
type FuncCtx
type InvalidValidationError
- func (e *InvalidValidationError) Error() string
type RegisterTranslationsFunc
type StructLevel
type StructLevelFunc
type StructLevelFuncCtx
type TagNameFunc
type TranslationFunc
type Validate
- func New() *Validate
- func (v *Validate) RegisterAlias(alias, tags string)
- func (v *Validate) RegisterCustomTypeFunc(fn CustomTypeFunc, types ...interface{})
- func (v *Validate) RegisterStructValidation(fn StructLevelFunc, types ...interface{})
- func (v *Validate) RegisterStructValidationCtx(fn StructLevelFuncCtx, types ...interface{})
- func (v *Validate) RegisterTagNameFunc(fn TagNameFunc)
- func (v *Validate) RegisterTranslation(tag string, trans ut.Translator, registerFn RegisterTranslationsFunc, ...) (err error)
- func (v *Validate) RegisterValidation(tag string, fn Func, callValidationEvenIfNull ...bool) error
- func (v *Validate) RegisterValidationCtx(tag string, fn FuncCtx, callValidationEvenIfNull ...bool) error
- func (v *Validate) SetTagName(name string)
- func (v *Validate) Struct(s interface{}) error
- func (v *Validate) StructCtx(ctx context.Context, s interface{}) (err error)
- func (v *Validate) StructExcept(s interface{}, fields ...string) error
- func (v *Validate) StructExceptCtx(ctx context.Context, s interface{}, fields ...string) (err error)
- func (v *Validate) StructFiltered(s interface{}, fn FilterFunc) error
- func (v *Validate) StructFilteredCtx(ctx context.Context, s interface{}, fn FilterFunc) (err error)
- func (v *Validate) StructPartial(s interface{}, fields ...string) error
- func (v *Validate) StructPartialCtx(ctx context.Context, s interface{}, fields ...string) (err error)
- func (v *Validate) Var(field interface{}, tag string) error
- func (v *Validate) VarCtx(ctx context.Context, field interface{}, tag string) (err error)
- func (v *Validate) VarWithValue(field interface{}, other interface{}, tag string) error
- func (v *Validate) VarWithValueCtx(ctx context.Context, field interface{}, other interface{}, tag string) (err error)
type ValidationErrors
- func (ve ValidationErrors) Error() string
- func (ve ValidationErrors) Translate(ut ut.Translator) ValidationErrorsTranslations
type ValidationErrorsTranslations

Constants ¶

This section is empty.

Variables ¶

This section is empty.

Functions ¶

This section is empty.

Types ¶

type CustomTypeFunc ¶

type CustomTypeFunc func(field reflect.Value) interface{}

CustomTypeFunc allows for overriding or adding custom field type handler functions field = field value of the type to return a value to be validated example Valuer from sql drive see https://golang.org/src/database/sql/driver/types.go?s=1210:1293#L29

type FieldError ¶

type FieldError interface {

	// returns the validation tag that failed. if the
	// validation was an alias, this will return the
	// alias name and not the underlying tag that failed.
	//
	// eg. alias "iscolor": "hexcolor|rgb|rgba|hsl|hsla"
	// will return "iscolor"
	Tag() string

	// returns the validation tag that failed, even if an
	// alias the actual tag within the alias will be returned.
	// If an 'or' validation fails the entire or will be returned.
	//
	// eg. alias "iscolor": "hexcolor|rgb|rgba|hsl|hsla"
	// will return "hexcolor|rgb|rgba|hsl|hsla"
	ActualTag() string

	// returns the namespace for the field error, with the tag
	// name taking precedence over the fields actual name.
	//
	// eg. JSON name "User.fname"
	//
	// See StructNamespace() for a version that returns actual names.
	//
	// NOTE: this field can be blank when validating a single primitive field
	// using validate.Field(...) as there is no way to extract it's name
	Namespace() string

	// returns the namespace for the field error, with the fields
	// actual name.
	//
	// eq. "User.FirstName" see Namespace for comparison
	//
	// NOTE: this field can be blank when validating a single primitive field
	// using validate.Field(...) as there is no way to extract it's name
	StructNamespace() string

	// returns the fields name with the tag name taking precedence over the
	// fields actual name.
	//
	// eq. JSON name "fname"
	// see StructField for comparison
	Field() string

	// returns the fields actual name from the struct, when able to determine.
	//
	// eq.  "FirstName"
	// see Field for comparison
	StructField() string

	// returns the actual fields value in case needed for creating the error
	// message
	Value() interface{}

	// returns the param value, in string form for comparison; this will also
	// help with generating an error message
	Param() string

	// Kind returns the Field's reflect Kind
	//
	// eg. time.Time's kind is a struct
	Kind() reflect.Kind

	// Type returns the Field's reflect Type
	//
	// // eg. time.Time's type is time.Time
	Type() reflect.Type

	// returns the FieldError's translated error
	// from the provided 'ut.Translator' and registered 'TranslationFunc'
	//
	// NOTE: if no registered translator can be found it returns the same as
	// calling fe.Error()
	Translate(ut ut.Translator) string
}

FieldError contains all functions to get error details

type FieldLevel ¶

type FieldLevel interface {
	// returns the top level struct, if any
	Top() reflect.Value

	// returns the current fields parent struct, if any or
	// the comparison value if called 'VarWithValue'
	Parent() reflect.Value

	// returns current field for validation
	Field() reflect.Value

	// returns the field's name with the tag
	// name taking precedence over the fields actual name.
	FieldName() string

	// returns the struct field's name
	StructFieldName() string

	// returns param for validation against current field
	Param() string

	// GetTag returns the current validations tag name
	GetTag() string

	// ExtractType gets the actual underlying type of field value.
	// It will dive into pointers, customTypes and return you the
	// underlying value and it's kind.
	ExtractType(field reflect.Value) (value reflect.Value, kind reflect.Kind, nullable bool)

	// traverses the parent struct to retrieve a specific field denoted by the provided namespace
	// in the param and returns the field, field kind and whether is was successful in retrieving
	// the field at all.
	//
	// NOTE: when not successful ok will be false, this can happen when a nested struct is nil and so the field
	// could not be retrieved because it didn't exist.
	//
	// Deprecated: Use GetStructFieldOK2() instead which also return if the value is nullable.
	GetStructFieldOK() (reflect.Value, reflect.Kind, bool)

	// GetStructFieldOKAdvanced is the same as GetStructFieldOK except that it accepts the parent struct to start looking for
	// the field and namespace allowing more extensibility for validators.
	//
	// Deprecated: Use GetStructFieldOKAdvanced2() instead which also return if the value is nullable.
	GetStructFieldOKAdvanced(val reflect.Value, namespace string) (reflect.Value, reflect.Kind, bool)

	// traverses the parent struct to retrieve a specific field denoted by the provided namespace
	// in the param and returns the field, field kind, if it's a nullable type and whether is was successful in retrieving
	// the field at all.
	//
	// NOTE: when not successful ok will be false, this can happen when a nested struct is nil and so the field
	// could not be retrieved because it didn't exist.
	GetStructFieldOK2() (reflect.Value, reflect.Kind, bool, bool)

	// GetStructFieldOKAdvanced is the same as GetStructFieldOK except that it accepts the parent struct to start looking for
	// the field and namespace allowing more extensibility for validators.
	GetStructFieldOKAdvanced2(val reflect.Value, namespace string) (reflect.Value, reflect.Kind, bool, bool)
}

FieldLevel contains all the information and helper functions to validate a field

type FilterFunc ¶

type FilterFunc func(ns []byte) bool

FilterFunc is the type used to filter fields using StructFiltered(...) function. returning true results in the field being filtered/skiped from validation

type Func ¶

type Func func(fl FieldLevel) bool

Func accepts a FieldLevel interface for all validation needs. The return value should be true when validation succeeds.

type FuncCtx ¶

type FuncCtx func(ctx context.Context, fl FieldLevel) bool

FuncCtx accepts a context.Context and FieldLevel interface for all validation needs. The return value should be true when validation succeeds.

type InvalidValidationError ¶

type InvalidValidationError struct {
	Type reflect.Type
}

InvalidValidationError describes an invalid argument passed to `Struct`, `StructExcept`, StructPartial` or `Field`

func (*InvalidValidationError) Error ¶

func (e *InvalidValidationError) Error() string

Error returns InvalidValidationError message

type RegisterTranslationsFunc ¶

type RegisterTranslationsFunc func(ut ut.Translator) error

RegisterTranslationsFunc allows for registering of translations for a 'ut.Translator' for use within the 'TranslationFunc'

type StructLevel ¶

type StructLevel interface {

	// returns the main validation object, in case one wants to call validations internally.
	// this is so you don't have to use anonymous functions to get access to the validate
	// instance.
	Validator() *Validate

	// returns the top level struct, if any
	Top() reflect.Value

	// returns the current fields parent struct, if any
	Parent() reflect.Value

	// returns the current struct.
	Current() reflect.Value

	// ExtractType gets the actual underlying type of field value.
	// It will dive into pointers, customTypes and return you the
	// underlying value and its kind.
	ExtractType(field reflect.Value) (value reflect.Value, kind reflect.Kind, nullable bool)

	// reports an error just by passing the field and tag information
	//
	// NOTES:
	//
	// fieldName and altName get appended to the existing namespace that
	// validator is on. e.g. pass 'FirstName' or 'Names[0]' depending
	// on the nesting
	//
	// tag can be an existing validation tag or just something you make up
	// and process on the flip side it's up to you.
	ReportError(field interface{}, fieldName, structFieldName string, tag, param string)

	// reports an error just by passing ValidationErrors
	//
	// NOTES:
	//
	// relativeNamespace and relativeActualNamespace get appended to the
	// existing namespace that validator is on.
	// e.g. pass 'User.FirstName' or 'Users[0].FirstName' depending
	// on the nesting. most of the time they will be blank, unless you validate
	// at a level lower the the current field depth
	ReportValidationErrors(relativeNamespace, relativeActualNamespace string, errs ValidationErrors)
}

StructLevel contains all the information and helper functions to validate a struct

type StructLevelFunc ¶

type StructLevelFunc func(sl StructLevel)

StructLevelFunc accepts all values needed for struct level validation

type StructLevelFuncCtx ¶

type StructLevelFuncCtx func(ctx context.Context, sl StructLevel)

StructLevelFuncCtx accepts all values needed for struct level validation but also allows passing of contextual validation information via context.Context.

type TagNameFunc ¶

type TagNameFunc func(field reflect.StructField) string

TagNameFunc allows for adding of a custom tag name parser

type TranslationFunc ¶

type TranslationFunc func(ut ut.Translator, fe FieldError) string

TranslationFunc is the function type used to register or override custom translations

type Validate ¶

type Validate struct {
	// contains filtered or unexported fields
}

Validate contains the validator settings and cache

func New ¶

func New() *Validate

New returns a new instance of 'validate' with sane defaults.

func (*Validate) RegisterAlias ¶

func (v *Validate) RegisterAlias(alias, tags string)

RegisterAlias registers a mapping of a single validation tag that defines a common or complex set of validation(s) to simplify adding validation to structs.

NOTE: this function is not thread-safe it is intended that these all be registered prior to any validation

func (*Validate) RegisterCustomTypeFunc ¶

func (v *Validate) RegisterCustomTypeFunc(fn CustomTypeFunc, types ...interface{})

RegisterCustomTypeFunc registers a CustomTypeFunc against a number of types

NOTE: this method is not thread-safe it is intended that these all be registered prior to any validation

func (*Validate) RegisterStructValidation ¶

func (v *Validate) RegisterStructValidation(fn StructLevelFunc, types ...interface{})

RegisterStructValidation registers a StructLevelFunc against a number of types.

NOTE: - this method is not thread-safe it is intended that these all be registered prior to any validation

func (*Validate) RegisterStructValidationCtx ¶

func (v *Validate) RegisterStructValidationCtx(fn StructLevelFuncCtx, types ...interface{})

RegisterStructValidationCtx registers a StructLevelFuncCtx against a number of types and allows passing of contextual validation information via context.Context.

NOTE: - this method is not thread-safe it is intended that these all be registered prior to any validation

func (*Validate) RegisterTagNameFunc ¶

func (v *Validate) RegisterTagNameFunc(fn TagNameFunc)

RegisterTagNameFunc registers a function to get alternate names for StructFields.

eg. to use the names which have been specified for JSON representations of structs, rather than normal Go field names:

validate.RegisterTagNameFunc(func(fld reflect.StructField) string {
    name := strings.SplitN(fld.Tag.Get("json"), ",", 2)[0]
    if name == "-" {
        return ""
    }
    return name
})

func (*Validate) RegisterTranslation ¶

func (v *Validate) RegisterTranslation(tag string, trans ut.Translator, registerFn RegisterTranslationsFunc, translationFn TranslationFunc) (err error)

RegisterTranslation registers translations against the provided tag.

func (*Validate) RegisterValidation ¶

func (v *Validate) RegisterValidation(tag string, fn Func, callValidationEvenIfNull ...bool) error

RegisterValidation adds a validation with the given tag

NOTES: - if the key already exists, the previous validation function will be replaced. - this method is not thread-safe it is intended that these all be registered prior to any validation

func (*Validate) RegisterValidationCtx ¶

func (v *Validate) RegisterValidationCtx(tag string, fn FuncCtx, callValidationEvenIfNull ...bool) error

RegisterValidationCtx does the same as RegisterValidation on accepts a FuncCtx validation allowing context.Context validation support.

func (*Validate) SetTagName ¶

func (v *Validate) SetTagName(name string)

SetTagName allows for changing of the default tag name of 'validate'

func (*Validate) Struct ¶

func (v *Validate) Struct(s interface{}) error

Struct validates a structs exposed fields, and automatically validates nested structs, unless otherwise specified.