通过删除数组来简化模板的使用

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.