// Copyright 2012-2014, 2017 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
// updatevalues.go - modify a value based on path and possibly sub-keys
// TODO(clb): handle simple elements with attributes and NewMapXmlSeq Map values.
package mxj
import (
"fmt"
"strconv"
"strings"
)
// Update value based on path and possible sub-key values.
// A count of the number of values changed and any error are returned.
// If the count == 0, then no path (and subkeys) matched.
// 'newVal' can be a Map or map[string]interface{} value with a single 'key' that is the key to be modified
// or a string value "key:value[:type]" where type is "bool" or "num" to cast the value.
// 'path' is dot-notation list of keys to traverse; last key in path can be newVal key
// NOTE: 'path' spec does not currently support indexed array references.
// 'subkeys' are "key:value[:type]" entries that must match for path node
// - For attributes prefix the label with the attribute prefix character, by default a
// hyphen, '-', e.g., "-seq:3". (See SetAttrPrefix function.)
// - The subkey can be wildcarded - "key:*" - to require that it's there with some value.
// - If a subkey is preceeded with the '!' character, the key:value[:type] entry is treated as an
// exclusion critera - e.g., "!author:William T. Gaddis".
//
// NOTES:
// 1. Simple elements with attributes need a path terminated as ".#text" to modify the actual value.
// 2. Values in Maps created using NewMapXmlSeq are map[string]interface{} values with a "#text" key.
// 3. If values in 'newVal' or 'subkeys' args contain ":", use SetFieldSeparator to an unused symbol,
// perhaps "|".
func (mv Map) UpdateValuesForPath(newVal interface{}, path string, subkeys ...string) (int, error) {
m := map[string]interface{}(mv)
// extract the subkeys
var subKeyMap map[string]interface{}
if len(subkeys) > 0 {
var err error
subKeyMap, err = getSubKeyMap(subkeys...)
if err != nil {
return 0, err
}
}
// extract key and value from newVal
var key string
var val interface{}
switch newVal.(type) {
case map[string]interface{}, Map:
switch newVal.(type) { // "fallthrough is not permitted in type switch" (Spec)
case Map:
newVal = newVal.(Map).Old()
}
if len(newVal.(map[string]interface{})) != 1 {
return 0, fmt.Errorf("newVal map can only have len == 1 - %+v", newVal)
}
for key, val = range newVal.(map[string]interface{}) {
}
case string: // split it as a key:value pair
ss := strings.Split(newVal.(string), fieldSep)
n := len(ss)
if n < 2 || n > 3 {
return 0, fmt.Errorf("unknown newVal spec - %+v", newVal)
}
key = ss[0]
if n == 2 {
val = interface{}(ss[1])
} else if n == 3 {
switch ss[2] {
case "bool", "boolean":
nv, err := strconv.ParseBool(ss[1])
if err != nil {
return 0, fmt.Errorf("can't convert newVal to bool - %+v", newVal)
}
val = interface{}(nv)
case "num", "numeric", "float", "int":
nv, err := strconv.ParseFloat(ss[1], 64)
if err != nil {
return 0, fmt.Errorf("can't convert newVal to float64 - %+v", newVal)
}
val = interface{}(nv)
default:
return 0, fmt.Errorf("unknown type for newVal value - %+v", newVal)
}
}
default:
return 0, fmt.Errorf("invalid newVal type - %+v", newVal)
}
// parse path
keys := strings.Split(path, ".")
var count int
updateValuesForKeyPath(key, val, m, keys, subKeyMap, &count)
return count, nil
}
// navigate the path
func updateValuesForKeyPath(key string, value interface{}, m interface{}, keys []string, subkeys map[string]interface{}, cnt *int) {
// ----- at end node: looking at possible node to get 'key' ----
if len(keys) == 1 {
updateValue(key, value, m, keys[0], subkeys, cnt)
return
}
// ----- here we are navigating the path thru the penultimate node --------
// key of interest is keys[0] - the next in the path
switch keys[0] {
case "*": // wildcard - scan all values
switch m.(type) {
case map[string]interface{}:
for _, v := range m.(map[string]interface{}) {
updateValuesForKeyPath(key, value, v, keys[1:], subkeys, cnt)
}
case []interface{}:
for _, v := range m.([]interface{}) {
switch v.(type) {
// flatten out a list of maps - keys are processed
case map[string]interface{}:
for _, vv := range v.(map[string]interface{}) {
updateValuesForKeyPath(key, value, vv, keys[1:], subkeys, cnt)
}
default:
updateValuesForKeyPath(key, value, v, keys[1:], subkeys, cnt)
}
}
}
default: // key - must be map[string]interface{}
switch m.(type) {
case map[string]interface{}:
if v, ok := m.(map[string]interface{})[keys[0]]; ok {
updateValuesForKeyPath(key, value, v, keys[1:], subkeys, cnt)
}
case []interface{}: // may be buried in list
for _, v := range m.([]interface{}) {
switch v.(type) {
case map[string]interface{}:
if vv, ok := v.(map[string]interface{})[keys[0]]; ok {
updateValuesForKeyPath(key, value, vv, keys[1:], subkeys, cnt)
}
}
}
}
}
}
// change value if key and subkeys are present
func updateValue(key string, value interface{}, m interface{}, keys0 string, subkeys map[string]interface{}, cnt *int) {
// there are two possible options for the value of 'keys0': map[string]interface, []interface{}
// and 'key' is a key in the map or is a key in a map in a list.
switch m.(type) {
case map[string]interface{}: // gotta have the last key
if keys0 == "*" {
for k := range m.(map[string]interface{}) {
updateValue(key, value, m, k, subkeys, cnt)
}
return
}
endVal, _ := m.(map[string]interface{})[keys0]
// if newV key is the end of path, replace the value for path-end
// may be []interface{} - means replace just an entry w/ subkeys
// otherwise replace the keys0 value if subkeys are there
// NOTE: this will replace the subkeys, also
if key == keys0 {
switch endVal.(type) {
case map[string]interface{}:
if hasSubKeys(m, subkeys) {
(m.(map[string]interface{}))[keys0] = value
(*cnt)++
}
case []interface{}:
// without subkeys can't select list member to modify
// so key:value spec is it ...
if hasSubKeys(m, subkeys) {
(m.(map[string]interface{}))[keys0] = value
(*cnt)++
break
}
nv := make([]interface{}, 0)
var valmodified bool
for _, v := range endVal.([]interface{}) {
// check entry subkeys
if hasSubKeys(v, subkeys) {
// replace v with value
nv = append(nv, value)
valmodified = true
(*cnt)++
continue
}
nv = append(nv, v)
}
if valmodified {
(m.(map[string]interface{}))[keys0] = interface{}(nv)
}
default: // anything else is a strict replacement
if hasSubKeys(m, subkeys) {
(m.(map[string]interface{}))[keys0] = value
(*cnt)++
}
}
return
}
// so value is for an element of endVal
// if endVal is a map then 'key' must be there w/ subkeys
// if endVal is a list then 'key' must be in a list member w/ subkeys
switch endVal.(type) {
case map[string]interface{}:
if !hasSubKeys(endVal, subkeys) {
return
}
if _, ok := (endVal.(map[string]interface{}))[key]; ok {
(endVal.(map[string]interface{}))[key] = value
(*cnt)++
}
case []interface{}: // keys0 points to a list, check subkeys
for _, v := range endVal.([]interface{}) {
// got to be a map so we can replace value for 'key'
vv, vok := v.(map[string]interface{})
if !vok {
continue
}
if _, ok := vv[key]; !ok {
continue
}
if !hasSubKeys(vv, subkeys) {
continue
}
vv[key] = value
(*cnt)++
}
}
case []interface{}: // key may be in a list member
// don't need to handle keys0 == "*"; we're looking at everything, anyway.
for _, v := range m.([]interface{}) {
// only map values - we're looking for 'key'
mm, ok := v.(map[string]interface{})
if !ok {
continue
}
if _, ok := mm[key]; !ok {
continue
}
if !hasSubKeys(mm, subkeys) {
continue
}
mm[key] = value
(*cnt)++
}
}
// return
}