tpl trick https://helm.sh/docs/howto/charts_tips_and_tricks/#using-the-tpl-function throws an error when used inside the range loop

[MilanMasek]

Output of helm version:
version.BuildInfo{Version:"v3.14.3", GitCommit:"f03cc04caaa8f6d7c3e67cf918929150cf6f3f12", GitTreeState:"clean", GoVersion:"go1.21.7"}

Following example works. When the first line of template/service.yaml is moved inside the range loop, it throws an error.

` 
$ cat values.yaml
mA: "my-awesome-app"
myApp:
appName: "{{ $.Values.mA }}-is-here"
replicas: 3
ports:
- 80
- 443
services:
- name: "web"
port: 80
- name: "api"
port: 8080

$ cat templates/service.yaml
app: {{ tpl $.Values.myApp.appName . }}
{{- range .Values.myApp.services }}
apiVersion: v1
kind: Service
metadata:
name: {{ .name }}-svc
spec:
ports:
- port: {{ .port }}
name: http
selector:
{{- end }}

`

When tpl is used like shown above anywhere inside the range loop, it throws an error:
 $ helm template . --values values.yaml Error: template: tt/templates/service.yaml:4:8: executing "tt/templates/service.yaml" at <tpl $.Values.myApp.appName .>: error calling tpl: error during tpl function execution for "{{ $.Values.mA }}-is-here": template: gotpl:1:4: executing "gotpl" at <$.Values.mA>: nil pointer evaluating interface {}.mA

[sabre1041]

@MilanMasek When you move it inside the range, the scope changes. Since you want to stay at the top, or "root" scope, replace the . with a $ as shown below:

app: {{ tpl $.Values.myApp.appName $ }}

[MilanMasek]

Understand - it works flawlessly! Thank you for educating me, @sabre1041!