--- /dev/null
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package query implements encoding of structs into URL query parameters.
+//
+// As a simple example:
+//
+// type Options struct {
+// Query string `url:"q"`
+// ShowAll bool `url:"all"`
+// Page int `url:"page"`
+// }
+//
+// opt := Options{ "foo", true, 2 }
+// v, _ := query.Values(opt)
+// fmt.Print(v.Encode()) // will output: "q=foo&all=true&page=2"
+//
+// The exact mapping between Go values and url.Values is described in the
+// documentation for the Values() function.
+package query
+
+import (
+ "bytes"
+ "fmt"
+ "net/url"
+ "reflect"
+ "strconv"
+ "strings"
+ "time"
+)
+
+var timeType = reflect.TypeOf(time.Time{})
+
+var encoderType = reflect.TypeOf(new(Encoder)).Elem()
+
+// Encoder is an interface implemented by any type that wishes to encode
+// itself into URL values in a non-standard way.
+type Encoder interface {
+ EncodeValues(key string, v *url.Values) error
+}
+
+// Values returns the url.Values encoding of v.
+//
+// Values expects to be passed a struct, and traverses it recursively using the
+// following encoding rules.
+//
+// Each exported struct field is encoded as a URL parameter unless
+//
+// - the field's tag is "-", or
+// - the field is empty and its tag specifies the "omitempty" option
+//
+// The empty values are false, 0, any nil pointer or interface value, any array
+// slice, map, or string of length zero, and any time.Time that returns true
+// for IsZero().
+//
+// The URL parameter name defaults to the struct field name but can be
+// specified in the struct field's tag value. The "url" key in the struct
+// field's tag value is the key name, followed by an optional comma and
+// options. For example:
+//
+// // Field is ignored by this package.
+// Field int `url:"-"`
+//
+// // Field appears as URL parameter "myName".
+// Field int `url:"myName"`
+//
+// // Field appears as URL parameter "myName" and the field is omitted if
+// // its value is empty
+// Field int `url:"myName,omitempty"`
+//
+// // Field appears as URL parameter "Field" (the default), but the field
+// // is skipped if empty. Note the leading comma.
+// Field int `url:",omitempty"`
+//
+// For encoding individual field values, the following type-dependent rules
+// apply:
+//
+// Boolean values default to encoding as the strings "true" or "false".
+// Including the "int" option signals that the field should be encoded as the
+// strings "1" or "0".
+//
+// time.Time values default to encoding as RFC3339 timestamps. Including the
+// "unix" option signals that the field should be encoded as a Unix time (see
+// time.Unix())
+//
+// Slice and Array values default to encoding as multiple URL values of the
+// same name. Including the "comma" option signals that the field should be
+// encoded as a single comma-delimited value. Including the "space" option
+// similarly encodes the value as a single space-delimited string. Including
+// the "semicolon" option will encode the value as a semicolon-delimited string.
+// Including the "brackets" option signals that the multiple URL values should
+// have "[]" appended to the value name. "numbered" will append a number to
+// the end of each incidence of the value name, example:
+// name0=value0&name1=value1, etc.
+//
+// Anonymous struct fields are usually encoded as if their inner exported
+// fields were fields in the outer struct, subject to the standard Go
+// visibility rules. An anonymous struct field with a name given in its URL
+// tag is treated as having that name, rather than being anonymous.
+//
+// Non-nil pointer values are encoded as the value pointed to.
+//
+// Nested structs are encoded including parent fields in value names for
+// scoping. e.g:
+//
+// "user[name]=acme&user[addr][postcode]=1234&user[addr][city]=SFO"
+//
+// All other values are encoded using their default string representation.
+//
+// Multiple fields that encode to the same URL parameter name will be included
+// as multiple URL values of the same name.
+func Values(v interface{}) (url.Values, error) {
+ values := make(url.Values)
+ val := reflect.ValueOf(v)
+ for val.Kind() == reflect.Ptr {
+ if val.IsNil() {
+ return values, nil
+ }
+ val = val.Elem()
+ }
+
+ if v == nil {
+ return values, nil
+ }
+
+ if val.Kind() != reflect.Struct {
+ return nil, fmt.Errorf("query: Values() expects struct input. Got %v", val.Kind())
+ }
+
+ err := reflectValue(values, val, "")
+ return values, err
+}
+
+// reflectValue populates the values parameter from the struct fields in val.
+// Embedded structs are followed recursively (using the rules defined in the
+// Values function documentation) breadth-first.
+func reflectValue(values url.Values, val reflect.Value, scope string) error {
+ var embedded []reflect.Value
+
+ typ := val.Type()
+ for i := 0; i < typ.NumField(); i++ {
+ sf := typ.Field(i)
+ if sf.PkgPath != "" && !sf.Anonymous { // unexported
+ continue
+ }
+
+ sv := val.Field(i)
+ tag := sf.Tag.Get("url")
+ if tag == "-" {
+ continue
+ }
+ name, opts := parseTag(tag)
+ if name == "" {
+ if sf.Anonymous && sv.Kind() == reflect.Struct {
+ // save embedded struct for later processing
+ embedded = append(embedded, sv)
+ continue
+ }
+
+ name = sf.Name
+ }
+
+ if scope != "" {
+ name = scope + "[" + name + "]"
+ }
+
+ if opts.Contains("omitempty") && isEmptyValue(sv) {
+ continue
+ }
+
+ if sv.Type().Implements(encoderType) {
+ if !reflect.Indirect(sv).IsValid() {
+ sv = reflect.New(sv.Type().Elem())
+ }
+
+ m := sv.Interface().(Encoder)
+ if err := m.EncodeValues(name, &values); err != nil {
+ return err
+ }
+ continue
+ }
+
+ if sv.Kind() == reflect.Slice || sv.Kind() == reflect.Array {
+ var del byte
+ if opts.Contains("comma") {
+ del = ','
+ } else if opts.Contains("space") {
+ del = ' '
+ } else if opts.Contains("semicolon") {
+ del = ';'
+ } else if opts.Contains("brackets") {
+ name = name + "[]"
+ }
+
+ if del != 0 {
+ s := new(bytes.Buffer)
+ first := true
+ for i := 0; i < sv.Len(); i++ {
+ if first {
+ first = false
+ } else {
+ s.WriteByte(del)
+ }
+ s.WriteString(valueString(sv.Index(i), opts))
+ }
+ values.Add(name, s.String())
+ } else {
+ for i := 0; i < sv.Len(); i++ {
+ k := name
+ if opts.Contains("numbered") {
+ k = fmt.Sprintf("%s%d", name, i)
+ }
+ values.Add(k, valueString(sv.Index(i), opts))
+ }
+ }
+ continue
+ }
+
+ for sv.Kind() == reflect.Ptr {
+ if sv.IsNil() {
+ break
+ }
+ sv = sv.Elem()
+ }
+
+ if sv.Type() == timeType {
+ values.Add(name, valueString(sv, opts))
+ continue
+ }
+
+ if sv.Kind() == reflect.Struct {
+ reflectValue(values, sv, name)
+ continue
+ }
+
+ values.Add(name, valueString(sv, opts))
+ }
+
+ for _, f := range embedded {
+ if err := reflectValue(values, f, scope); err != nil {
+ return err
+ }
+ }
+
+ return nil
+}
+
+// valueString returns the string representation of a value.
+func valueString(v reflect.Value, opts tagOptions) string {
+ for v.Kind() == reflect.Ptr {
+ if v.IsNil() {
+ return ""
+ }
+ v = v.Elem()
+ }
+
+ if v.Kind() == reflect.Bool && opts.Contains("int") {
+ if v.Bool() {
+ return "1"
+ }
+ return "0"
+ }
+
+ if v.Type() == timeType {
+ t := v.Interface().(time.Time)
+ if opts.Contains("unix") {
+ return strconv.FormatInt(t.Unix(), 10)
+ }
+ return t.Format(time.RFC3339)
+ }
+
+ return fmt.Sprint(v.Interface())
+}
+
+// isEmptyValue checks if a value should be considered empty for the purposes
+// of omitting fields with the "omitempty" option.
+func isEmptyValue(v reflect.Value) bool {
+ switch v.Kind() {
+ case reflect.Array, reflect.Map, reflect.Slice, reflect.String:
+ return v.Len() == 0
+ case reflect.Bool:
+ return !v.Bool()
+ case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+ return v.Int() == 0
+ case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
+ return v.Uint() == 0
+ case reflect.Float32, reflect.Float64:
+ return v.Float() == 0
+ case reflect.Interface, reflect.Ptr:
+ return v.IsNil()
+ }
+
+ if v.Type() == timeType {
+ return v.Interface().(time.Time).IsZero()
+ }
+
+ return false
+}
+
+// tagOptions is the string following a comma in a struct field's "url" tag, or
+// the empty string. It does not include the leading comma.
+type tagOptions []string
+
+// parseTag splits a struct field's url tag into its name and comma-separated
+// options.
+func parseTag(tag string) (string, tagOptions) {
+ s := strings.Split(tag, ",")
+ return s[0], s[1:]
+}
+
+// Contains checks whether the tagOptions contains the specified option.
+func (o tagOptions) Contains(option string) bool {
+ for _, s := range o {
+ if s == option {
+ return true
+ }
+ }
+ return false
+}
projects / github / fretlink / terraform-provider-statuscake.git / blobdiff