Files
hugo/docs/content/en/functions/default.md
2022-04-08 13:32:01 +02:00

2.4 KiB

title, description, qref, date, publishdate, lastmod, keywords, categories, menu, toc, signature, workson, hugoversion, relatedfuncs, deprecated, draft, aliases
title description qref date publishdate lastmod keywords categories menu toc signature workson hugoversion relatedfuncs deprecated draft aliases
default Allows setting a default value that can be returned if a first value is not set. Returns a default value if a value is not set when checked. 2017-02-01 2017-02-01 2017-02-01
defaults
functions
docs
parent
functions
default DEFAULT INPUT
false false

default checks whether a given value is set and returns a default value if it is not. Set in this context means different things depending on the data type:

  • non-zero for numeric types and times
  • non-zero length for strings, arrays, slices, and maps
  • any boolean or struct value
  • non-nil for any other types

default function examples reference the following content page:

{{< code file="content/posts/default-function-example.md" >}}

title: Sane Defaults seo_title: date: 2017-02-18 font: oldparam: The default function helps make your templating DRYer. newparam:

{{< /code >}}

default can be written in more than one way:

{{ index .Params "font" | default "Roboto" }}
{{ default "Roboto" (index .Params "font") }}

Both of the above default function calls return Roboto.

A default value, however, does not need to be hard coded like the previous example. The default value can be a variable or pulled directly from the front matter using dot notation:

{{< code file="variable-as-default-value.html" nocopy="true" >}} {{$old := .Params.oldparam }}

{{ .Params.newparam | default $old }}

{{< /code >}}

Which would return:

<p>The default function helps make your templating DRYer.</p>

And then using dot notation

{{< code file="dot-notation-default-value.html" >}}

{{< /code >}}

Which would return

{{< output file="dot-notation-default-return-value.html" >}}

{{< /output >}}

The following have equivalent return values but are far less terse. This demonstrates the utility of default:

Using if:

{{< code file="if-instead-of-default.html" nocopy="true" >}}

=> Sane Defaults {{< /code >}}

Using with:

{{< code file="with-instead-of-default.html" nocopy="true" >}}

=> Sane Defaults {{< /code >}}