Golang text/template multiple conditions with !not operator

Question

How can I chain multiple conditions using indirect template functions in Go?

I want to check if .hello doesn't contain "world" and .world doesn't contain "hello", but I cannot because I got 2009/11/10 23:00:00 executing template: template: content:2:5: executing "content" at <not>: wrong number of args for not: want 1 got 2 error message

package main

import (
    "log"
    "os"
    "strings"
    "text/template"
)

var (
    templateFuncMap = template.FuncMap{
        "contains": strings.Contains,
    }
)

func main() {
    // Define a template.
    const temp = `
{{if not (contains .hello "hello") (contains .world "hello") }}
        passed
{{else}}
        not passed
{{end}}`

    s := map[string]string{
        "hello": "world",
        "world": "hello",
    }

    t := template.Must(template.New("content").Funcs(templateFuncMap).Parse(temp))
    err := t.Execute(os.Stdout, s)
    if err != nil {
        log.Println("executing template:", err)
    }

}

Go playground link: https://go.dev/play/p/lWZwjbnSewy

Answer 1

not expects one argument, so yo have to use parenthesis.

If you do, the condition you want to negate is contains "hello" or contains "world":

{{if not (or (contains .hello "hello") (contains .world "hello")) }}

This will output (try it on the Go Playground):

    not passed

You can also write this condition as not contains "hello" and not contains "world", which would look like this:

{{if and (not (contains .hello "hello")) (not (contains .world "hello")) }}