Add XML payload support

Fixes #238

vendor/github.com/clbanning/mxj/newmap.go

@@ -0,0 +1,184 @@
+// mxj - A collection of map[string]interface{} and associated XML and JSON utilities.
+// Copyright 2012-2014, 2018 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
+
+// remap.go - build a new Map from the current Map based on keyOld:keyNew mapppings
+//            keys can use dot-notation, keyOld can use wildcard, '*'
+//
+// Computational strategy -
+// Using the key path - []string - traverse a new map[string]interface{} and
+// insert the oldVal as the newVal when we arrive at the end of the path.
+// If the type at the end is nil, then that is newVal
+// If the type at the end is a singleton (string, float64, bool) an array is created.
+// If the type at the end is an array, newVal is just appended.
+// If the type at the end is a map, it is inserted if possible or the map value
+//    is converted into an array if necessary.
+
+package mxj
+
+import (
+	"errors"
+	"strings"
+)
+
+// (Map)NewMap - create a new Map from data in the current Map.
+//	'keypairs' are key mappings "oldKey:newKey" and specify that the current value of 'oldKey'
+//	should be the value for 'newKey' in the returned Map.
+//		- 'oldKey' supports dot-notation as described for (Map)ValuesForPath()
+//		- 'newKey' supports dot-notation but with no wildcards, '*', or indexed arrays
+//		- "oldKey" is shorthand for the keypair value "oldKey:oldKey"
+//		- "oldKey:" and ":newKey" are invalid keypair values
+//		- if 'oldKey' does not exist in the current Map, it is not written to the new Map.
+//		  "null" is not supported unless it is the current Map.
+//		- see newmap_test.go for several syntax examples
+// 	- mv.NewMap() == mxj.New()
+//
+//	NOTE: "examples/partial.go" shows how to create arbitrary sub-docs of an XML doc.
+func (mv Map) NewMap(keypairs ...string) (Map, error) {
+	n := make(map[string]interface{}, 0)
+	if len(keypairs) == 0 {
+		return n, nil
+	}
+
+	// loop through the pairs
+	var oldKey, newKey string
+	var path []string
+	for _, v := range keypairs {
+		if len(v) == 0 {
+			continue // just skip over empty keypair arguments
+		}
+
+		// initialize oldKey, newKey and check
+		vv := strings.Split(v, ":")
+		if len(vv) > 2 {
+			return n, errors.New("oldKey:newKey keypair value not valid - " + v)
+		}
+		if len(vv) == 1 {
+			oldKey, newKey = vv[0], vv[0]
+		} else {
+			oldKey, newKey = vv[0], vv[1]
+		}
+		strings.TrimSpace(oldKey)
+		strings.TrimSpace(newKey)
+		if i := strings.Index(newKey, "*"); i > -1 {
+			return n, errors.New("newKey value cannot contain wildcard character - " + v)
+		}
+		if i := strings.Index(newKey, "["); i > -1 {
+			return n, errors.New("newKey value cannot contain indexed arrays - " + v)
+		}
+		if oldKey == "" || newKey == "" {
+			return n, errors.New("oldKey or newKey is not specified - " + v)
+		}
+
+		// get oldKey value
+		oldVal, err := mv.ValuesForPath(oldKey)
+		if err != nil {
+			return n, err
+		}
+		if len(oldVal) == 0 {
+			continue // oldKey has no value, may not exist in mv
+		}
+
+		// break down path
+		path = strings.Split(newKey, ".")
+		if path[len(path)-1] == "" { // ignore a trailing dot in newKey spec
+			path = path[:len(path)-1]
+		}
+
+		addNewVal(&n, path, oldVal)
+	}
+
+	return n, nil
+}
+
+// navigate 'n' to end of path and add val
+func addNewVal(n *map[string]interface{}, path []string, val []interface{}) {
+	// newVal - either singleton or array
+	var newVal interface{}
+	if len(val) == 1 {
+		newVal = val[0] // is type interface{}
+	} else {
+		newVal = interface{}(val)
+	}
+
+	// walk to the position of interest, create it if necessary
+	m := (*n)           // initialize map walker
+	var k string        // key for m
+	lp := len(path) - 1 // when to stop looking
+	for i := 0; i < len(path); i++ {
+		k = path[i]
+		if i == lp {
+			break
+		}
+		var nm map[string]interface{} // holds position of next-map
+		switch m[k].(type) {
+		case nil: // need a map for next node in path, so go there
+			nm = make(map[string]interface{}, 0)
+			m[k] = interface{}(nm)
+			m = m[k].(map[string]interface{})
+		case map[string]interface{}:
+			// OK - got somewhere to walk to, go there
+			m = m[k].(map[string]interface{})
+		case []interface{}:
+			// add a map and nm points to new map unless there's already
+			// a map in the array, then nm points there
+			// The placement of the next value in the array is dependent
+			// on the sequence of members - could land on a map or a nil
+			// value first.  TODO: how to test this.
+			a := make([]interface{}, 0)
+			var foundmap bool
+			for _, vv := range m[k].([]interface{}) {
+				switch vv.(type) {
+				case nil: // doesn't appear that this occurs, need a test case
+					if foundmap { // use the first one in array
+						a = append(a, vv)
+						continue
+					}
+					nm = make(map[string]interface{}, 0)
+					a = append(a, interface{}(nm))
+					foundmap = true
+				case map[string]interface{}:
+					if foundmap { // use the first one in array
+						a = append(a, vv)
+						continue
+					}
+					nm = vv.(map[string]interface{})
+					a = append(a, vv)
+					foundmap = true
+				default:
+					a = append(a, vv)
+				}
+			}
+			// no map found in array
+			if !foundmap {
+				nm = make(map[string]interface{}, 0)
+				a = append(a, interface{}(nm))
+			}
+			m[k] = interface{}(a) // must insert in map
+			m = nm
+		default: // it's a string, float, bool, etc.
+			aa := make([]interface{}, 0)
+			nm = make(map[string]interface{}, 0)
+			aa = append(aa, m[k], nm)
+			m[k] = interface{}(aa)
+			m = nm
+		}
+	}
+
+	// value is nil, array or a singleton of some kind
+	// initially m.(type) == map[string]interface{}
+	v := m[k]
+	switch v.(type) {
+	case nil: // initialized
+		m[k] = newVal
+	case []interface{}:
+		a := m[k].([]interface{})
+		a = append(a, newVal)
+		m[k] = interface{}(a)
+	default: // v exists:string, float64, bool, map[string]interface, etc.
+		a := make([]interface{}, 0)
+		a = append(a, v, newVal)
+		m[k] = interface{}(a)
+	}
+}