Param

The Param method on a Page object looks for the given KEY in page parameters, and returns the corresponding value. If it cannot find the KEY in page parameters, it looks for the KEY in site parameters. If it cannot find the KEY in either location, the Param method returns nil.

Use the Param method to access custom fields. To access a reserved field, call the corresponding method on a Page object, such as Description. To fall back to a site parameter when the reserved field is empty, use the or function:

{{ or .Description site.Params.description }}

Site and theme developers commonly set parameters at the site level, allowing content authors to override those parameters at the page level.

For example, to show a table of contents on every page, but allow authors to hide the table of contents as needed:

Configuration:

params:
  display_toc: true

[params]
  display_toc = true

{
   "params": {
      "display_toc": true
   }
}

Content:

---
date: '2023-01-01'
draft: false
params:
  display_toc: false
title: Example
---

+++
date = 2023-01-01
draft = false
title = 'Example'
[params]
  display_toc = false
+++

{
   "date": "2023-01-01",
   "draft": false,
   "params": {
      "display_toc": false
   },
   "title": "Example"
}

Template:

{{ if .Param "display_toc" }}
  {{ .TableOfContents }}
{{ end }}

The Param method returns the value associated with the given KEY, regardless of whether the value is truthy or falsy. If you need to ignore falsy values, use this construct instead:

{{ or .Params.foo site.Params.foo }}