Package validator
Package vad 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
Installation
Use go get.
go get github.com/askasoft/pango
Then import the validator package into your own code.
import "github.com/askasoft/pango/vad"
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 returns only InvalidValidationError for bad validation input, nil or ValidationErrors as type error; so, in your code all you need to do is check if the error returned is not nil, and if it's not check if error is InvalidValidationError ( if necessary, most of the time it isn't ) type cast it to type ValidationErrors like so:
err := validate.Struct(mystruct)
validationErrors := err.(vad.ValidationErrors)
Usage and documentation
Examples:
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 |
| httpurl | URL (https?://) String |
| httpsurl | URL (https://) String |
Strings:
| Tag | Description |
|---|
| letter | Ascii Letter Only |
| letternum | Ascii Letter or Number |
| utfletter | Unicode Letter |
| utfletternum | Unicode Letter or Number |
| ascii | ASCII |
| boolean | Boolean |
| contains | Contains |
| containsany | Contains Any |
| containsrune | Contains Rune |
| endsnotwith | Ends 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 |
| decimal | Decimal |
| printable | Printable Unicode |
| 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) |
| datetime | Datetime |
| duration | Duration |
| 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 |
| ne | Not Equal |
| gt | Greater than |
| gte | Greater than or equal |
| min | Greater than or equal |
| lt | Less Than |
| lte | Less Than or Equal |
| max | Less Than or Equal |
| btw | Between |
Length:
| Tag | Description |
|---|
| len | (string's rune count, slice/map length) Equal |
| maxlen | (string's rune count, slice/map length) Maximum |
| minlen | (string's rune count, slice/map length) Minimum |
| btwlen | (string's rune count, slice/map length) Between |
Other:
| Tag | Description |
|---|
| dir | Directory |
| file | File path |
| isdefault | Is Default |
| 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_with | Excluded With |
| excluded_with_all | Excluded With All |
| excluded_without | Excluded Without |
| excluded_without_all | Excluded Without All |
| unique | Unique |
| regexp | Regular Expression Match |
Aliases:
| Tag | Description |
|---|
| iscolor | hexcolor|rgb|rgba|hsl|hsla |
| alpha | letter |
| alphanum | letternum |
| alphaunicode | utfletter |
| alphanumunicode | utfletternum |