service/vendor/github.com/clbanning/mxj/v2/misc.go

87 lines
2.5 KiB
Go

// Copyright 2016 Charles Banning. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file
// misc.go - mimic functions (+others) called out in:
// https://groups.google.com/forum/#!topic/golang-nuts/jm_aGsJNbdQ
// Primarily these methods let you retrive XML structure information.
package mxj
import (
"fmt"
"sort"
"strings"
)
// Return the root element of the Map. If there is not a single key in Map,
// then an error is returned.
func (mv Map) Root() (string, error) {
mm := map[string]interface{}(mv)
if len(mm) != 1 {
return "", fmt.Errorf("Map does not have singleton root. Len: %d.", len(mm))
}
for k, _ := range mm {
return k, nil
}
return "", nil
}
// If the path is an element with sub-elements, return a list of the sub-element
// keys. (The list is alphabeticly sorted.) NOTE: Map keys that are prefixed with
// '-', a hyphen, are considered attributes; see m.Attributes(path).
func (mv Map) Elements(path string) ([]string, error) {
e, err := mv.ValueForPath(path)
if err != nil {
return nil, err
}
switch e.(type) {
case map[string]interface{}:
ee := e.(map[string]interface{})
elems := make([]string, len(ee))
var i int
for k, _ := range ee {
if len(attrPrefix) > 0 && strings.Index(k, attrPrefix) == 0 {
continue // skip attributes
}
elems[i] = k
i++
}
elems = elems[:i]
// alphabetic sort keeps things tidy
sort.Strings(elems)
return elems, nil
}
return nil, fmt.Errorf("no elements for path: %s", path)
}
// If the path is an element with attributes, return a list of the attribute
// keys. (The list is alphabeticly sorted.) NOTE: Map keys that are not prefixed with
// '-', a hyphen, are not treated as attributes; see m.Elements(path). Also, if the
// attribute prefix is "" - SetAttrPrefix("") or PrependAttrWithHyphen(false) - then
// there are no identifiable attributes.
func (mv Map) Attributes(path string) ([]string, error) {
a, err := mv.ValueForPath(path)
if err != nil {
return nil, err
}
switch a.(type) {
case map[string]interface{}:
aa := a.(map[string]interface{})
attrs := make([]string, len(aa))
var i int
for k, _ := range aa {
if len(attrPrefix) == 0 || strings.Index(k, attrPrefix) != 0 {
continue // skip non-attributes
}
attrs[i] = k[len(attrPrefix):]
i++
}
attrs = attrs[:i]
// alphabetic sort keeps things tidy
sort.Strings(attrs)
return attrs, nil
}
return nil, fmt.Errorf("no attributes for path: %s", path)
}