package lazyschema
import "golazy.dev/lazyschema"Functions
func FieldID
FieldID returns the DOM id for a schema path.
func FieldID(path Path, opts ...NameOption) (string, error)func FieldIDFor
FieldIDFor returns the generated DOM id for a Go field path.
func FieldIDFor(model any, field string, opts ...NameOption) (string, error)func FieldName
FieldName returns the form field name for a schema path.
func FieldName(path Path, _ ...NameOption) (string, error)func FieldNameFor
FieldNameFor returns the generated form field name for a Go field path.
func FieldNameFor(model any, field string, opts ...NameOption) (string, error)func FormatTime
FormatTime formats a time value for HTML date and time inputs.
func FormatTime(t time.Time, inputType string) stringfunc ModelName
ModelName returns the default lower-camel key for a model value or type.
func ModelName(model any) (string, error)func ModelNameForType
ModelNameForType returns the default lower-camel key for a struct type.
func ModelNameForType(t reflect.Type) (string, error)Types
type ConversionError
ConversionError stores information about a failed conversion.
type ConversionError struct {
Key string // key from the source map.
Type reflect.Type // expected type of elem
Index int // index for multi-value fields; -1 for single-value fields.
Err error // low-level error (when it exists)
}func (e ConversionError) Error
func (e ConversionError) Error() stringtype Converter
type Converter func(string) reflect.Valuetype Decoder
Decoder decodes values from a map[string][]string to a struct.
type Decoder struct {
// contains filtered or unexported fields
}func NewDecoder
NewDecoder returns a new Decoder.
func NewDecoder() *Decoderfunc (d *Decoder) Decode
Decode decodes a map[string][]string to a struct.
The first parameter must be a pointer to a struct.
The second parameter is a map, typically url.Values from an HTTP request. Keys are "paths" in dotted notation to the struct fields and nested structs.
See the package documentation for a full explanation of the mechanics.
func (d *Decoder) Decode(dst interface{}, src map[string][]string) errorfunc (d *Decoder) IgnoreUnknownKeys
IgnoreUnknownKeys controls the behaviour when the decoder encounters unknown keys in the map. If i is true and an unknown field is encountered, it is ignored. This is similar to how unknown keys are handled by encoding/json. If i is false then Decode will return an error. Note that any valid keys will still be decoded in to the target struct.
To preserve backwards compatibility, the default value is false.
func (d *Decoder) IgnoreUnknownKeys(i bool)func (d *Decoder) MaxDepth
MaxDepth limits the number of nested path segments in each submitted key.
func (d *Decoder) MaxDepth(size int)func (d *Decoder) MaxKeyLength
MaxKeyLength limits the length of each submitted key.
func (d *Decoder) MaxKeyLength(size int)func (d *Decoder) MaxKeys
MaxKeys limits how many distinct form keys one Decode call accepts.
func (d *Decoder) MaxKeys(size int)func (d *Decoder) MaxSize
MaxSize limits the size of slices for URL nested arrays or object arrays. Choose MaxSize carefully; large values may create many zero-value slice elements. Example: "items.100000=apple" would create a slice with 100,000 empty strings.
func (d *Decoder) MaxSize(size int)func (d *Decoder) MaxValuesPerKey
MaxValuesPerKey limits how many submitted values one key accepts.
func (d *Decoder) MaxValuesPerKey(size int)func (d *Decoder) RegisterConverter
RegisterConverter registers a converter function for a custom type.
func (d *Decoder) RegisterConverter(value interface{}, converterFunc Converter)func (d *Decoder) SetAliasTag
SetAliasTag changes the tag used to locate custom field aliases. The default tag is "schema".
func (d *Decoder) SetAliasTag(tag string)func (d *Decoder) ZeroEmpty
ZeroEmpty controls the behaviour when the decoder encounters empty values in a map. If z is true and a key in the map has the empty string as a value then the corresponding struct field is set to the zero value. If z is false then empty strings are ignored.
The default value is false, that is empty values do not change the value of the struct field.
func (d *Decoder) ZeroEmpty(z bool)type EmptyFieldError
EmptyFieldError stores information about an empty required field.
type EmptyFieldError struct {
Key string // required key in the source map.
}func (e EmptyFieldError) Error
func (e EmptyFieldError) Error() stringtype Encoder
Encoder encodes values from a struct into url.Values.
type Encoder struct {
// contains filtered or unexported fields
}func NewEncoder
NewEncoder returns a new Encoder with defaults.
func NewEncoder() *Encoderfunc (e *Encoder) Encode
Encode encodes a struct into map[string][]string.
Intended for use with url.Values.
func (e *Encoder) Encode(src interface{}, dst map[string][]string) errorfunc (e *Encoder) RegisterEncoder
RegisterEncoder registers a converter for encoding a custom type.
func (e *Encoder) RegisterEncoder(value interface{}, encoder func(reflect.Value) string)func (e *Encoder) SetAliasTag
SetAliasTag changes the tag used to locate custom field aliases. The default tag is "schema".
func (e *Encoder) SetAliasTag(tag string)type MultiError
MultiError stores multiple decoding errors.
Borrowed from the App Engine SDK.
type MultiError map[string]errorfunc (e MultiError) Error
func (e MultiError) Error() stringtype NameConflictError
NameConflictError reports two exported struct fields with the same generated schema key.
type NameConflictError struct {
Type reflect.Type
Key string
Fields []string
}func (e NameConflictError) Error
func (e NameConflictError) Error() stringtype NameOption
NameOption configures generated field names and ids.
type NameOption func(*nameOptions)func WithPrefix
WithPrefix prefixes generated field ids with a model or form key.
func WithPrefix(prefix string) NameOptiontype Path
Path is a schema field path made of generated field aliases and optional slice indices.
type Path []stringfunc PathFor
PathFor returns the generated schema path for a Go field path such as "Phone.Label" or "Phones.0.Number".
func PathFor(model any, field string) (Path, error)type UnknownKeyError
UnknownKeyError stores information about an unknown key in the source map.
type UnknownKeyError struct {
Key string // key from the source map.
}func (e UnknownKeyError) Error
func (e UnknownKeyError) Error() string
Package lazyschema fills structs from form values and generates the field names used by GoLazy forms.
The package is adapted from Gorilla schema. It keeps Gorilla's reflection-based decoder model, converters, required/default tag options, and slice protection, but GoLazy owns the generated key format.
The default field key is lower-camel per Go field segment, with underscores for nested paths:
type Person struct { Name string Phone Phone } type Phone struct { Label string Number string } values := map[string][]string{ "name": {"Ada"}, "phone_label": {"mobile"}, "phone_number": {"555-0100"}, } var person Person decoder := lazyschema.NewDecoder() err := decoder.Decode(&person, values)Slices of structs include explicit numeric indexes:
type Person struct { Phones []Phone } values := map[string][]string{ "phones_0_label": {"home"}, "phones_0_number": {"555-0100"}, "phones_1_label": {"work"}, "phones_1_number": {"555-0101"}, }Use the "schema" struct tag to override names or ignore fields:
type Person struct { Name string `schema:"fullName"` Admin bool `schema:"-"` }The same package generates field names and ids, so form helpers and decoding stay aligned:
name, _ := lazyschema.FieldNameFor(Person{}, "Phone.Number") id, _ := lazyschema.FieldIDFor(Person{}, "Phone.Number", lazyschema.WithPrefix("person"))The supported field types match Gorilla schema's core types: bools, strings, integers, floats, structs, pointers to supported types, and slices. Custom types can be registered with RegisterConverter. time.Time is registered by default for common HTML date, time, and datetime input values.