go - What's the easiest way to define a custom HTML-stringification?

Question

Is there a way for me to define that when I just output a value in Go html templates the way the formatting is done instead of it printing a string representation without having to call a function to explicitcly convert it?

For example, let's say I have a type Person and I have a template with just {{.}} I want it to automatically create a link to that person's page but if I use the same template and passed a value of a different type some other HTML will be generated.

What I don't want to do is having to write something like {{.HTML}} or {{. | html}}. I'm already aware that these are possible but my question is specifically about how to avoid those.

I've played around with the thought of Person.String() having return the HTML code somehow without it being escaped but besides not getting that to work it also seems like an ugly solution.

Another solution I've thought about is to just pass everything as HTML into the template but then I couldn't access the attributes anymore (like {{.name}} to output just the name) and I'd also have to convert everything into HTML just in case it's used in the template.

question from:https://stackoverflow.com/questions/65920132/whats-the-easiest-way-to-define-a-custom-html-stringification

Answer 1

Create a method that returns an template.HTML type. i.e.:

func (p *Person) HTML() template.HTML {
    return fmt.Sprintf(`<a href="/person/%v">%s</a>`, p.id, template.HTMLEscapeString(p.name))
}

Then in your template:

{{ .HTML }}