Simplify template usage by removing array - templates

Question

I am trying to simplify the template which I use to make it use a flatter data structure:
from
data := []App{App{"test data", []string{"app1", "app2", "app3"}}}
To:
data := App{App{"test data", []string{"app1", "app2", "app3"}}}
i.e. Remove the array of App, but when I try it I get an error.
Here is the working version: https://play.golang.org/p/2THGtDvlu01
I tried to change the template to
{{ range . -}}
{range $i,$a := .Command}{{if gt $i 0 }} && {{end}}{{.}}{{end}}
{{end}}
But I got an error of type mismatched, any idea how to fix it?

Answer 1

package main
import (
"log"
"os"
"text/template"
)
func main() {
// Define a template.
const tmpl = `
echo &1
{{range $i,$a := .Command}}{{if gt $i 0 }} && {{end}}{{.}}{{end}}
echo 2
`
// Prepare some data
type App struct {
Data string
Command []string
}
data := App{"test data", []string{"app1", "app2", "app3"}}
// Create a new template and parse into it.
t := template.Must(template.New("tmpl").Parse(tmpl))
// Execute the template with data
err := t.Execute(os.Stdout, data)
if err != nil {
log.Println("executing template:", err)
}
}
Playground example
Gives the output
echo &1
app1 && app2 && app3
echo 2
Program exited.
If you remove the []App from your code, you also need to remove the range used in the template.