How to Capture Go Template Output and Assign it to a Variable?

Capture or Assign Go Template Output to Variable Within a Go template, the goal is to emulate the following:

{{$var := template "my-template"}} However, this approach results in the error "unexpected in operand."

Solution Go does not provide an inbuilt method to capture template execution results. Instead, register a function that performs this task.

Function Registration Use the Template.Funcs() function to register functions. Execute named templates with Template.ExecuteTemplate() and use a bytes.Buffer as the target to capture the direct template execution result into a buffer.

Example package main

import ( "bytes" "html/template" "log" "os" )

var t *template.Template

func execTempl(name string) (string, error) { buf := &bytes.Buffer{} err := t.ExecuteTemplate(buf, name, nil) return buf.String(), err }

func main() { t = template.Must(template.New("").Funcs(template.FuncMap{ "execTempl": execTempl, }).Parse(tmpl)) if err := t.Execute(os.Stdout, nil); err != nil { log.Fatal(err) } }

const tmpl = `{{define "my-template"}}my-template content{{end}} See result: {{$var := execTempl "my-template"}} {{$var}} ` Usage Execute the "my-template" template using the registered execTempl() function. Store the result in the $var template variable, which can then be added to the output or passed to other functions.

Output See result: my-template content Note that the output captures the result of the "my-template" template and displays it within the main template.

How to Capture Go Template Output and Assign it to a Variable?

Capture or Assign Go Template Output to Variable

Solution

Function Registration

Example

Usage

Output

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