define
Syntax
define NAME
Use with the block statement:
{{ block "main" . }}
  {{ print "default value if 'main' template is empty" }}
{{ end }}
{{ define "main" }}
  <h1>{{ .Title }}</h1>
  {{ .Content }}
{{ end }}
Use with the partial function:
{{ partial "inline/foo.html" (dict "answer" 42) }}
{{ define "partials/inline/foo.html" }}
  {{ printf "The answer is %v." .answer }}
{{ end }}
Use with the template function:
{{ template "foo" (dict "answer" 42) }}
{{ define "foo" }}
  {{ printf "The answer is %v." .answer }}
{{ end }}
See Go’s text/template documentation for more information.