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Diffstat (limited to 'docs/content/en/functions/safe/JS.md')
-rw-r--r-- | docs/content/en/functions/safe/JS.md | 50 |
1 files changed, 45 insertions, 5 deletions
diff --git a/docs/content/en/functions/safe/JS.md b/docs/content/en/functions/safe/JS.md index 65279b89b..d0d3a227a 100644 --- a/docs/content/en/functions/safe/JS.md +++ b/docs/content/en/functions/safe/JS.md @@ -13,14 +13,54 @@ action: - functions/safe/URL returnType: template.JS signatures: [safe.JS INPUT] +toc: true aliases: [/functions/safejs] --- -In this context, *safe* means the string encapsulates a known safe EcmaScript5 Expression (e.g., `(x + y * z())`). +## Introduction -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. +{{% include "functions/_common/go-html-template-package.md" %}} -Example: Given `hash = "619c16f"` defined in the front matter of your `.md` file: +## Usage -* `<script>var form_{{ .Params.hash | safeJS }};…</script>` → `<script>var form_619c16f;…</script>` -* `<script>var form_{{ .Params.hash }};…</script>` → `<script>var form_"619c16f";…</script>` +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> +``` |