mirror of
https://github.com/gohugoio/hugo.git
synced 2024-11-14 20:37:55 -05:00
64 lines
2.4 KiB
Markdown
64 lines
2.4 KiB
Markdown
---
|
|
aliases:
|
|
- /doc/scratch/
|
|
lastmod: 2015-08-02
|
|
date: 2015-01-22
|
|
menu:
|
|
main:
|
|
parent: extras
|
|
next: /extras/datafiles
|
|
prev: /extras/pagination
|
|
title: Scratch
|
|
weight: 80
|
|
---
|
|
|
|
`Scratch` -- a "scratchpad" for your page-scoped variables. In most cases you can do well without `Scratch`, but there are some use cases that aren't solvable with Go's templates without `Scratch`'s help, due to scoping issues.
|
|
|
|
`Scratch` is added to both `Page` and `Shortcode` -- with following methods:
|
|
|
|
* `Set` and `Add` takes a `key` and the `value` to add.
|
|
* `Get` returns the `value` for the `key` given.
|
|
* `SetInMap` takes a `key`, `mapKey` and `value`
|
|
* `GetSortedMapValues` returns array of values from `key` sorted by `mapKey`
|
|
|
|
`Set` and `SetInMap` can store values of any type.
|
|
|
|
For single values, `Add` accepts values that support Go's `+` operator. If the first `Add` for a key is an array or slice, the following adds will be appended to that list.
|
|
|
|
The scope of the backing data is global for the given `Page` or `Shortcode`, and spans partial and shortcode includes.
|
|
|
|
Note that `.Scratch` from a shortcode will return the shortcode's `Scratch`, which in most cases is what you want. If you want to store it in the page scroped Scratch, then use `.Page.Scratch`.
|
|
|
|
## Sample usage
|
|
|
|
The usage is best illustrated with some samples:
|
|
|
|
```
|
|
{{ $.Scratch.Add "a1" 12 }}
|
|
{{ $.Scratch.Get "a1" }} {{/* => 12 */}}
|
|
{{ $.Scratch.Add "a1" 1 }}
|
|
{{ $.Scratch.Get "a1" }} // {{/* => 13 */}}
|
|
|
|
{{ $.Scratch.Add "a2" "AB" }}
|
|
{{ $.Scratch.Get "a2" }} {{/* => AB */}}
|
|
{{ $.Scratch.Add "a2" "CD" }}
|
|
{{ $.Scratch.Get "a2" }} {{/* => ABCD */}}
|
|
|
|
{{ $.Scratch.Add "l1" (slice "A" "B") }}
|
|
{{ $.Scratch.Get "l1" }} {{/* => [A B] */}}
|
|
{{ $.Scratch.Add "l1" (slice "C" "D") }}
|
|
{{ $.Scratch.Get "l1" }} {{/* => [A B C D] */}}
|
|
|
|
{{ $.Scratch.Set "v1" 123 }}
|
|
{{ $.Scratch.Get "v1" }} {{/* => 123 */}}
|
|
|
|
{{ $.Scratch.SetInMap "a3" "b" "XX" }}
|
|
{{ $.Scratch.SetInMap "a3" "a" "AA" }}
|
|
{{ $.Scratch.SetInMap "a3" "c" "CC" }}
|
|
{{ $.Scratch.SetInMap "a3" "b" "BB" }}
|
|
{{ $.Scratch.GetSortedMapValues "a3" }} {{/* => []interface {}{"AA", "BB", "CC"} */}}
|
|
```
|
|
|
|
**Note:** The examples above uses the special `$` variable, which refers to the top-level node. This is the behavior you most likely want, and will help remove some confusion when using `Scratch` inside page range loops -- and you start inadvertently calling the wrong `Scratch`. But there may be use cases for `{{ .Scratch.Add "key" "some value" }}`.
|
|
|
|
|