Shortcode with html like boolean attribute

support
1

In HTML, you can have boolean attributes, an example is the checked attribute of the input element. According to the HTML specification, the presence of a boolean attribute on an element represents the true value, and the absence of the attribute represents the false value.

I tried to mimic a HTML like attribute with a Hugo shortcode, with partial success only.
What I did so far: I authored a shortcode checkbox.html, this shortcode is supposed to get a html-like checked attribute :

{{ with .Params  }}
  {{- if index . "checked" -}}
    ☑ Checked item
  {{- else -}}
    ☑ Checked item
  {{end}}
{{- else -}}
  ☐ Unchecked item
{{ end }}

I now use this shortcode in my pages like this:

{{% checkbox checked=true %}}

{{% checkbox checked="true" %}}

{{% checkbox %}}

and it correctly prints out

☑ Checked item
☑ Checked item
☐ Unchecked item

However, if I specify the checked attribute as wanted (html like, without any value):

{{% checkbox checked %}}

I’m running into this error:

failed to process shortcode: "my\path\checkbox.html:2:9":
execute of template failed: template: shortcodes/checkbox.html:2:9:
executing "shortcodes/checkbox.html" at <index . "checked">:
error calling index: cannot index slice/array with type string

Any way to make this work?

2

Shortcode attributes are either named or positional:

{{ $checked := .Get 0 | default "" }}

See Create your own shortcodes | Hugo