Golang template : Use pipe to uppercase string

manuquentin picture manuquentin · Jan 9, 2014 · Viewed 12.9k times · Source

I want to upper case a string in a golang template using string.ToUpper like :

{{ .Name | strings.ToUpper  }}

But this doesn't works because strings is not a property of my data.

I can't import strings package because the warns me that it's not used.

Here the script : http://play.golang.org/p/7D69Q57WcN

Answer

Nick Craig-Wood picture Nick Craig-Wood · Jan 9, 2014

Just use a FuncMap like this (playground) to inject the ToUpper function into your template.

import (
    "bytes"
    "fmt"
    "strings"
    "text/template"
)

type TemplateData struct {
    Name string
}

func main() {
    funcMap := template.FuncMap{
        "ToUpper": strings.ToUpper,
    }

    tmpl, _ := template.New("myTemplate").Funcs(funcMap).Parse(string("{{ .Name | ToUpper  }}"))

    templateDate := TemplateData{"Hello"}
    var result bytes.Buffer

    tmpl.Execute(&result, templateDate)
    fmt.Println(result.String())
}