feat (payload) Get() accept paths.like.this[15]

context/contextFactory.go

@@ -75,7 +75,7 @@ func (context *Context) BrokerDelegates() *moleculer.BrokerDelegates {
 	return context.broker
 }
 
-// ChildActionContext : create a chiold context for a specific action call.
+// ChildActionContext : create a child context for a specific action call.
 func (context *Context) ChildActionContext(actionName string, params moleculer.Payload, opts ...moleculer.Options) moleculer.BrokerContext {
 	parentContext := context
 	meta := parentContext.meta

moleculer.go

@@ -52,6 +52,7 @@ type Payload interface {
 	Time() time.Time
 	TimeArray() []time.Time
 	Array() []Payload
+	At(index int) Payload
 	Len() int
 	Get(path string, defaultValue ...interface{}) Payload
 	//Only return a payload containing only the field specified

payload/payload.go

@@ -3,6 +3,7 @@ package payload
 import (
 	"errors"
 	"fmt"
+	"regexp"
 	"sort"
 	"strconv"
 	"strings"
@@ -216,6 +217,17 @@ func (p *RawPayload) First() moleculer.Payload {
 	return New(nil)
 }
 
+//At returns the item at the given index
+func (p *RawPayload) At(index int) moleculer.Payload {
+	if transformer := ArrayTransformer(&p.source); transformer != nil {
+		l := transformer.InterfaceArray(&p.source)
+		if index >= 0 && index < len(l) {
+			return New(l[index])
+		}
+	}
+	return nil
+}
+
 func (p *RawPayload) Array() []moleculer.Payload {
 	if transformer := ArrayTransformer(&p.source); transformer != nil {
 		source := transformer.InterfaceArray(&p.source)
@@ -439,7 +451,62 @@ func (p *RawPayload) mapGet(path string) (interface{}, bool) {
 	return nil, false
 }
 
-func (p *RawPayload) Get(path string, defaultValue ...interface{}) moleculer.Payload {
+func isPath(s string) bool {
+	return strings.Contains(s, ".")
+}
+
+var indexedKey = regexp.MustCompile(`^(\w+)\[(\d+)\]$`)
+
+//isIndexed checks if key is indexed e.g. stage[0]
+func isIndexed(s string) bool {
+	return indexedKey.MatchString(s)
+}
+
+func splitIndex(s string) (key string, index int) {
+	parts := indexedKey.FindStringSubmatch(s)
+	key = parts[1]
+	index, _ = strconv.Atoi(parts[2])
+	return key, index
+}
+
+func (p *RawPayload) Get(s string, defaultValue ...interface{}) moleculer.Payload {
+	//check if is a path of key
+	if isPath(s) {
+		if defaultValue != nil {
+			return p.getPath(s, defaultValue)
+		}
+		return p.getPath(s)
+	}
+	if isIndexed(s) {
+		k, index := splitIndex(s)
+		var v moleculer.Payload
+		if defaultValue != nil {
+			v = p.getKey(k, defaultValue)
+		} else {
+			v = p.getKey(k)
+		}
+		return v.At(index)
+	}
+	if defaultValue != nil {
+		return p.getKey(s, defaultValue)
+	}
+	return p.getKey(s)
+}
+
+//getPath get a value using a path expression e.g. address.country.code
+// it also accepts indexed lists like address.options[0].label
+func (p *RawPayload) getPath(path string, defaultValue ...interface{}) moleculer.Payload {
+	parts := strings.Split(path, ".")
+	k := parts[0]
+	v := p.Get(k, defaultValue)
+	for i := 1; i < len(parts); i++ {
+		k = parts[i]
+		v = v.Get(k, defaultValue)
+	}
+	return v
+}
+
+func (p *RawPayload) getKey(path string, defaultValue ...interface{}) moleculer.Payload {
 	if value, ok := p.mapGet(path); ok {
 		return New(value)
 	}

payload/payload_test.go

@@ -347,4 +347,32 @@ var _ = Describe("Payload", func() {
 		Expect(snap.SnapshotMulti("PayloadError() .Error()", p.Error())).ShouldNot(HaveOccurred())
 		Expect(snap.SnapshotMulti("PayloadError() .ErrorPayload()", p.ErrorPayload())).ShouldNot(HaveOccurred())
 	})
+
+	type M map[string]interface{}
+	It("should deal field paths name.subname...", func() {
+		p := New(M{
+			"name":     "John",
+			"lastname": "Snow",
+			"address": M{
+				"street": "jonny ave",
+				"country": M{
+					"code": "NZ",
+					"name": "New Zealand",
+				},
+				"options": []M{
+					M{
+						"label": "item 1",
+					},
+					M{
+						"label": "item 2",
+					},
+				},
+			},
+		})
+		Expect(p.Get("name").String()).Should(Equal("John"))
+		Expect(p.Get("address.street").String()).Should(Equal("jonny ave"))
+		Expect(p.Get("address.country.code").String()).Should(Equal("NZ"))
+		Expect(p.Get("address.options[0].label").String()).Should(Equal("item 1"))
+		Expect(p.Get("address.options[1].label").String()).Should(Equal("item 2"))
+	})
 })

serializer/jsonSerializer.go

@@ -498,6 +498,17 @@ func (payload JSONPayload) TimeArray() []time.Time {
 	return nil
 }
 
+func (payload JSONPayload) At(index int) moleculer.Payload {
+	if payload.IsArray() {
+		source := payload.result.Array()
+		if index >= 0 && index < len(source) {
+			item := source[index]
+			return JSONPayload{item, payload.logger}
+		}
+	}
+	return nil
+}
+
 func (payload JSONPayload) Array() []moleculer.Payload {
 	if payload.IsArray() {
 		source := payload.result.Array()