Merge pull request #232 from aarongreenlee/v8

Revisions to GoDoc
pull/233/merge
Dean Karn 9 years ago
commit d370e28d44
  1. 728
      doc.go

728
doc.go

@ -1,12 +1,16 @@
/*
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.
Package validator implements value validations for structs and individual fields
based on tags.
Why not a better error message? because this library intends for you to handle your own error messages.
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.
Why should I handle my own errors? Many reasons, for us building an internationalized application
I needed to know the field and what validation failed so that I could provide an error in the users specific language.
Why not a better error message?
Because this library intends for you to handle your own error messages.
Why should I handle my own errors?
Many reasons. We built an internationalized application and needed to know the
field, and what validation failed so we could provide a localized error.
if fieldErr.Field == "Name" {
switch fieldErr.ErrorTag
@ -16,22 +20,27 @@ I needed to know the field and what validation failed so that I could provide an
return "Translated string based on field"
}
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.
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:
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 only returns nil or ValidationErrors as type error; so in you code all you need to do
is check if the error returned is not nil, and if it's not type cast it to type ValidationErrors
like so err.(validator.ValidationErrors)
Validator only returns 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
type cast it to type ValidationErrors like so err.(validator.ValidationErrors).
Custom Functions
Custom functions can be added
Custom functions can be added. Example:
// Structure
func customFunc(v *Validate, topStruct reflect.Value, currentStructOrField reflect.Value, field reflect.Value, fieldType reflect.Type, fieldKind reflect.Kind, param string) bool {
@ -47,15 +56,31 @@ Custom functions can be added
// NOTES: using the same tag name as an existing function
// will overwrite the existing one
Cross Field Validation
Cross-Field Validation
Cross Field Validation can be done via the following tags: eqfield, nefield, gtfield, gtefield,
ltfield, ltefield, eqcsfield, necsfield, gtcsfield, ftecsfield, ltcsfield and ltecsfield. If
however some custom cross field validation is required, it can be done using a custom validation.
Cross-Field Validation can be done via the following tags:
- eqfield
- nefield
- gtfield
- gtefield
- ltfield
- ltefield
- eqcsfield
- necsfield
- gtcsfield
- ftecsfield
- ltcsfield
- ltecsfield
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.
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
@ -87,7 +112,7 @@ on the same struct, 1 level; but if we used eqcsfield it could be multiple level
Multiple Validators
Multiple validators on a field will process in the order defined
Multiple validators on a field will process in the order defined. Example:
type Test struct {
Field `validate:"max=10,min=1"`
@ -95,7 +120,7 @@ Multiple validators on a field will process in the order defined
// max will be checked then min
Bad Validator definitions are not handled by the library
Bad Validator definitions are not handled by the library. Example:
type Test struct {
Field `validate:"min=10,max=0"`
@ -103,407 +128,658 @@ Bad Validator definitions are not handled by the library
// this definition of min max will never succeed
Baked In Validators and Tags
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 default separator of validation tags. 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
NOTE: Baked In Cross field validation only compares fields on the same struct,
if cross field + cross struct validation is needed your own custom validator
should be implemented.
type Test struct {
Field `validate:"excludesall=|"` // BAD! Do not include a a pipe!
Field `validate:"excludesall=0x7C"` // GOOD! Use the UTF-8 hex representation.
}
NOTE2: 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
NOTE3: pipe is the default separator of or validation tags, 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
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 particularily
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: rbg|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)
structonly
When a field that is a nest struct in encountered and contains this flag
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 usefull if inside of you 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.
nostructlevel
Usage: structonly
NoStructLevel
Same as structonly tag except that any struct level validations will not run.
exists
Usage: nostructlevel
Exists
Is a special tag without a validation function attached. It is used when a field
is a Pointer, Interface or Invalid and you wish to validate that it exists.
Example: want to ensure a bool exists if you define the bool as a pointer and
use exists it will ensure there is a value; couldn't use required as it would
fail when the bool was false. exists will fail is the value is a Pointer, Interface
or Invalid and is nil. (Usage: exists)
or Invalid and is nil.
Usage: exists
Omit Empty
omitempty
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
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. (Usage: dive)
Example: [][]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
Example2: [][]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
required
require another dive tag.
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
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)
len
Usage: required
Length
For numbers, max 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)
arrays, and maps, validates the number of items.
Usage: len=10
Maximum
max
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)
slices, arrays, and maps, validates the number of items.
Usage: max=10
Mininum
min
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)
arrays, and maps, validates the number of items.
Usage: min=10
Equals
eq
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)
validates the number of items.
Usage: eq=10
Not Equal
ne
For strings & numbers, eq will ensure that the value is not
equal to the parameter given. For slices, arrays, and maps,
validates the number of items. (Usage: eq=10)
validates the number of items.
Usage: eq=10
Greater Than
gt
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. (Usage: gt=10)
For time.Time ensures the time value is greater than time.Now.UTC()
(Usage: gt)
gte
Same as 'min' above. Kept both to make terminology with 'len' easier
(Usage: gte=10)
For time.Time ensures the time value is greater than or equal to time.Now.UTC()
(Usage: gte)
lt
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.
(Usage: lt=10)
For time.Time ensures the time value is less than time.Now.UTC()
(Usage: lt)
lte
Same as 'max' above. Kept both to make terminology with 'len' easier
(Usage: lte=10)
For time.Time ensures the time value is less than or equal to time.Now.UTC()
(Usage: lte)
eqfield
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.
usage examples are for validation of a password and confirm password:
Validation on Password field using validate.Struct Usage(eqfield=ConfirmPassword)
Validating by field validate.FieldWithValue(password, confirmpassword, "eqfield")
eqcsfield
Example #1:
// Validation on Password field using:
Usage: eqfield=ConfirmPassword
Example #2:
// Validating by field:
validate.FieldWithValue(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)
to the top level struct.
Usage: eqcsfield=InnerStructField.Field)
Field Does Not Equal Another Field
nefield
This will validate the field value against another fields value either within
a struct or passed in field.
usage examples are for ensuring two colors are not the same:
Validation on Color field using validate.Struct Usage(nefield=Color2)
Validating by field validate.FieldWithValue(color1, color2, "nefield")
necsfield
This does the same as nefield except that it validates the field provided relative
to the top level struct. (Usage: necsfield=InnerStructField.Field)
Examples:
// Confirm two colors are not the same:
//
// Validation on Color field:
Usage: nefield=Color2
// Validating by field:
validate.FieldWithValue(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
gtfield
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:
Validation on End field using validate.Struct Usage(gtfield=Start)
Validating by field validate.FieldWithValue(start, end, "gtfield")
gtcsfield
This does the same as gtfield except that it validates the field provided relative
to the top level struct. (Usage: gtcsfield=InnerStructField.Field)
Example #1:
// Validation on End field using:
validate.Struct Usage(gtfield=Start)
Example #2:
// Validating by field:
validate.FieldWithValue(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
gtefield
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:
Validation on End field using validate.Struct Usage(gtefield=Start)
Validating by field validate.FieldWithValue(start, end, "gtefield")
gtecsfield
Example #1:
// Validation on End field using:
validate.Struct Usage(gtefield=Start)
Example #2:
// Validating by field:
validate.FieldWithValue(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)
to the top level struct.
Usage: gtecsfield=InnerStructField.Field
Less Than Another Field
ltfield
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:
Validation on End field using validate.Struct Usage(ltfield=Start)
Validating by field validate.FieldWithValue(start, end, "ltfield")
ltcsfield
Example #1:
// Validation on End field using:
validate.Struct Usage(ltfield=Start)
Example #2:
// Validating by field:
validate.FieldWithValue(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)
to the top level struct.
Usage: ltcsfield=InnerStructField.Field
Less Than or Equal To Another Field
ltefield
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:
Validation on End field using validate.Struct Usage(ltefield=Start)
Validating by field validate.FieldWithValue(start, end, "ltefield")
ltecsfield
Example #1:
// Validation on End field using:
validate.Struct Usage(ltefield=Start)
Example #2:
// Validating by field:
validate.FieldWithValue(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)
to the top level struct.
Usage: ltecsfield=InnerStructField.Field
Alpha Only
alpha
This validates that a string value contains alpha characters only
(Usage: alpha)
alphanum
Usage: alpha
Alphanumeric
This validates that a string value contains alphanumeric characters only
(Usage: alphanum)
numeric
Usage: alphanum
Numeric
This validates that a string value contains a basic numeric value.
basic excludes exponents etc...
(Usage: numeric)
hexadecimal
Usage: numeric
Hexadecimal String
This validates that a string value contains a valid hexadecimal.
(Usage: hexadecimal)
hexcolor
Usage: hexadecimal
Hexcolor String
This validates that a string value contains a valid hex color including
hashtag (#)
(Usage: hexcolor)
rgb
Usage: hexcolor
RGB String
This validates that a string value contains a valid rgb color
(Usage: rgb)
rgba
Usage: rgb
RGBA String
This validates that a string value contains a valid rgba color
(Usage: rgba)
hsl
Usage: rgba
HSL String
This validates that a string value contains a valid hsl color
(Usage: hsl)
hsla
Usage: hsl
HSLA String
This validates that a string value contains a valid hsla color
(Usage: hsla)
email
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 posibilities...
(Usage: email)
does any email provider accept all posibilities.
Usage: email
URL String
url
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
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)
This will accept any uri the golang request uri accepts
Usage: uri
Base64 String
base64
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)
this with the omitempty tag.
Usage: base64
Contains
contains
This validates that a string value contains the substring value.
(Usage: contains=@)
containsany
Usage: contains=@
Contains Any
This validates that a string value contains any Unicode code points
in the substring value. (Usage: containsany=!@#?)
in the substring value.
Usage: containsany=!@#?
Contains Rune
containsrune
This validates that a string value contains the supplied rune value.
(Usage: containsrune=@)
excludes
Usage: containsrune=@
Excludes
This validates that a string value does not contain the substring value.
(Usage: excludes=@)
excludesall
Usage: excludes=@
Excludes All
This validates that a string value does not contain any Unicode code
points in the substring value. (Usage: excludesall=!@#?)
points in the substring value.
Usage: excludesall=!@#?
Excludes Rune
excludesrune
This validates that a string value does not contain the supplied rune value.
(Usage: excludesrune=@)
isbn
Usage: excludesrune=@
International Standard Book Number
This validates that a string value contains a valid isbn10 or isbn13 value.
(Usage: isbn)
isbn10
Usage: isbn
International Standard Book Number 10
This validates that a string value contains a valid isbn10 value.
(Usage: isbn10)
isbn13
Usage: isbn10
International Standard Book Number 13
This validates that a string value contains a valid isbn13 value.
(Usage: isbn13)
uuid
Usage: isbn13
Universally Unique Identifier UUID
This validates that a string value contains a valid UUID.
(Usage: uuid)
uuid3
Usage: uuid
Universally Unique Identifier UUID v3
This validates that a string value contains a valid version 3 UUID.
(Usage: uuid3)
uuid4
Usage: uuid3
Universally Unique Identifier UUID v4
This validates that a string value contains a valid version 4 UUID.
(Usage: uuid4)
uuid5
Usage: uuid4
Universally Unique Identifier UUID v5
This validates that a string value contains a valid version 5 UUID.
(Usage: uuid5)
ascii
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)
asciiprint
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: asciiprint)
multibyte
Usage: asciiprint
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)
datauri
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
Usage: datauri
Latitude
This validates that a string value contains a valid latitude.
(Usage: latitude)
longitude
Usage: latitude
Longitude
This validates that a string value contains a valid longitude.
(Usage: longitude)
ssn
Usage: longitude
Social Security Number SSN
This validates that a string value contains a valid U.S. Social Security Number.
(Usage: ssn)
ip
Usage: ssn
Internet Protocol Address IP
This validates that a string value contains a valid IP Adress.
(Usage: ip)
ipv4
Usage: ip
Internet Protocol Address IPv4
This validates that a string value contains a valid v4 IP Adress.
(Usage: ipv4)
ipv6
Usage: ipv4
Internet Protocol Address IPv6
This validates that a string value contains a valid v6 IP Adress.
(Usage: ipv6)
cidr
Usage: ipv6
Classless Inter-Domain Routing CIDR
This validates that a string value contains a valid CIDR Adress.
(Usage: cidr)
cidrv4
Usage: cidr
Classless Inter-Domain Routing CIDRv4
This validates that a string value contains a valid v4 CIDR Adress.
(Usage: cidrv4)
cidrv6
Usage: cidrv4
Classless Inter-Domain Routing CIDRv6
This validates that a string value contains a valid v6 CIDR Adress.
(Usage: cidrv6)
mac
This validates that a string value contains a valid MAC Adress defined
by go's ParseMAC accepted formats and types see:
Usage: cidrv6
Media Access Control Address MAC
This validates that a string value contains a valid MAC Adress.
Usage: mac
Note: See Go's ParseMAC for accepted formats and types:
http://golang.org/src/net/mac.go?s=866:918#L29
(Usage: mac)
Usage: mac
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.
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
"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 philosiphy as anything.
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 philosiphy
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.
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!
And the best reason, you can submit a pull request and we can keep on
adding to the validation library of this package!
Panics
This package panics when bad input is provided, this is by design, bad code like that should not make it to production.
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"`

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