mirror of https://github.com/gohugoio/hugo
67 lines
1.8 KiB
Markdown
67 lines
1.8 KiB
Markdown
---
|
|
title: safe.JS
|
|
description: Declares the given string as a safe JavaScript expression.
|
|
categories: []
|
|
keywords: []
|
|
action:
|
|
aliases: [safeJS]
|
|
related:
|
|
- functions/safe/CSS
|
|
- functions/safe/HTML
|
|
- functions/safe/HTMLAttr
|
|
- functions/safe/JSStr
|
|
- functions/safe/URL
|
|
returnType: template.JS
|
|
signatures: [safe.JS INPUT]
|
|
toc: true
|
|
aliases: [/functions/safejs]
|
|
---
|
|
|
|
## Introduction
|
|
|
|
{{% include "functions/_common/go-html-template-package.md" %}}
|
|
|
|
## Usage
|
|
|
|
Use the `safe.JS` function to encapsulate a known safe EcmaScript5 Expression.
|
|
|
|
Template authors are responsible for ensuring that typed expressions do not break the intended precedence and that there is no statement/expression ambiguity as when passing an expression like `{ foo: bar() }\n['foo']()`, which is both a valid Expression and a valid Program with a very different meaning.
|
|
|
|
Use of this type presents a security risk: the encapsulated content should come from a trusted source, as it will be included verbatim in the template output.
|
|
|
|
Using the `safe.JS` function to include valid but untrusted JSON is not safe. A safe alternative is to parse the JSON with the [`transform.Unmarshal`] function and then pass the resultant object into the template, where it will be converted to sanitized JSON when presented in a JavaScript context.
|
|
|
|
[`transform.Unmarshal`]: /functions/transform/unmarshal/
|
|
|
|
See the [Go documentation] for details.
|
|
|
|
[Go documentation]: https://pkg.go.dev/html/template#JS
|
|
|
|
## Example
|
|
|
|
Without a safe declaration:
|
|
|
|
```go-html-template
|
|
{{ $js := "x + y" }}
|
|
<script>const a = {{ $js }}</script>
|
|
```
|
|
|
|
Hugo renders the above to:
|
|
|
|
```html
|
|
<script>const a = "x + y"</script>
|
|
```
|
|
|
|
To declare the string as safe:
|
|
|
|
```go-html-template
|
|
{{ $js := "x + y" }}
|
|
<script>const a = {{ $js | safeJS }}</script>
|
|
```
|
|
|
|
Hugo renders the above to:
|
|
|
|
```html
|
|
<script>const a = x + y</script>
|
|
```
|