1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301
|
---
title: transform.Unmarshal
description: Parses serialized data and returns a map or an array. Supports CSV, JSON, TOML, YAML, and XML.
categories: []
keywords: []
action:
aliases: [unmarshal]
related:
- functions/transform/Remarshal
- functions/resources/Get
- functions/resources/GetRemote
- functions/encoding/Jsonify
returnType: any
signatures: ['transform.Unmarshal [OPTIONS] INPUT']
toc: true
aliases: [/functions/transform.unmarshal]
---
The input can be a string or a [resource].
## Unmarshal a string
```go-html-template
{{ $string := `
title: Les Misérables
author: Victor Hugo
`}}
{{ $book := unmarshal $string }}
{{ $book.title }} → Les Misérables
{{ $book.author }} → Victor Hugo
```
## Unmarshal a resource
Use the `transform.Unmarshal` function with global, page, and remote resources.
### Global resource
A global resource is a file within the assets directory, or within any directory mounted to the assets directory.
```text
assets/
└── data/
└── books.json
```
```go-html-template
{{ $data := dict }}
{{ $path := "data/books.json" }}
{{ with resources.Get $path }}
{{ with . | transform.Unmarshal }}
{{ $data = . }}
{{ end }}
{{ else }}
{{ errorf "Unable to get global resource %q" $path }}
{{ end }}
{{ range where $data "author" "Victor Hugo" }}
{{ .title }} → Les Misérables
{{ end }}
```
### Page resource
A page resource is a file within a [page bundle].
```text
content/
├── post/
│ └── book-reviews/
│ ├── books.json
│ └── index.md
└── _index.md
```
```go-html-template
{{ $data := dict }}
{{ $path := "books.json" }}
{{ with .Resources.Get $path }}
{{ with . | transform.Unmarshal }}
{{ $data = . }}
{{ end }}
{{ else }}
{{ errorf "Unable to get page resource %q" $path }}
{{ end }}
{{ range where $data "author" "Victor Hugo" }}
{{ .title }} → Les Misérables
{{ end }}
```
### Remote resource
A remote resource is a file on a remote server, accessible via HTTP or HTTPS.
```go-html-template
{{ $data := dict }}
{{ $url := "https://example.org/books.json" }}
{{ with resources.GetRemote $url }}
{{ with .Err }}
{{ errorf "%s" . }}
{{ else }}
{{ $data = . | transform.Unmarshal }}
{{ end }}
{{ else }}
{{ errorf "Unable to get remote resource %q" $url }}
{{ end }}
{{ range where $data "author" "Victor Hugo" }}
{{ .title }} → Les Misérables
{{ end }}
```
{{% note %}}
When retrieving remote data, a misconfigured server may send a response header with an incorrect [Content-Type]. For example, the server may set the Content-Type header to `application/octet-stream` instead of `application/json`.
In these cases, pass the resource `Content` through the `transform.Unmarshal` function instead of passing the resource itself. For example, in the above, do this instead:
`{{ $data = .Content | transform.Unmarshal }}`
[Content-Type]: https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Type
{{% /note %}}
## Options
When unmarshaling a CSV file, provide an optional map of options.
delimiter
: (`string`) The delimiter used, default is `,`.
comment
: (`string`) The comment character used in the CSV. If set, lines beginning with the comment character without preceding whitespace are ignored.
lazyQuotes {{< new-in 0.122.0 >}}
: (`bool`) If true, a quote may appear in an unquoted field and a non-doubled quote may appear in a quoted field. Default is `false`.
```go-html-template
{{ $csv := "a;b;c" | transform.Unmarshal (dict "delimiter" ";") }}
```
## Working with XML
When unmarshaling an XML file, do not include the root node when accessing data. For example, after unmarshaling the RSS feed below, access the feed title with `$data.channel.title`.
```xml
<?xml version="1.0" encoding="utf-8" standalone="yes"?>
<rss version="2.0" xmlns:atom="http://www.w3.org/2005/Atom">
<channel>
<title>Books on Example Site</title>
<link>https://example.org/books/</link>
<description>Recent content in Books on Example Site</description>
<language>en-US</language>
<atom:link href="https://example.org/books/index.xml" rel="self" type="application/rss+xml" />
<item>
<title>The Hunchback of Notre Dame</title>
<description>Written by Victor Hugo</description>
<link>https://example.org/books/the-hunchback-of-notre-dame/</link>
<pubDate>Mon, 09 Oct 2023 09:27:12 -0700</pubDate>
<guid>https://example.org/books/the-hunchback-of-notre-dame/</guid>
</item>
<item>
<title>Les Misérables</title>
<description>Written by Victor Hugo</description>
<link>https://example.org/books/les-miserables/</link>
<pubDate>Mon, 09 Oct 2023 09:27:11 -0700</pubDate>
<guid>https://example.org/books/les-miserables/</guid>
</item>
</channel>
</rss>
```
Get the remote data:
```go-html-template
{{ $data := dict }}
{{ $url := "https://example.org/books/index.xml" }}
{{ with resources.GetRemote $url }}
{{ with .Err }}
{{ errorf "%s" . }}
{{ else }}
{{ $data = . | transform.Unmarshal }}
{{ end }}
{{ else }}
{{ errorf "Unable to get remote resource %q" $url }}
{{ end }}
```
Inspect the data structure:
```go-html-template
<pre>{{ debug.Dump $data }}</pre>
```
List the book titles:
```go-html-template
{{ with $data.channel.item }}
<ul>
{{ range . }}
<li>{{ .title }}</li>
{{ end }}
</ul>
{{ end }}
```
Hugo renders this to:
```html
<ul>
<li>The Hunchback of Notre Dame</li>
<li>Les Misérables</li>
</ul>
```
### XML attributes and namespaces
Let's add a `lang` attribute to the `title` nodes of our RSS feed, and a namespaced node for the ISBN number:
```xml
<?xml version="1.0" encoding="utf-8" standalone="yes"?>
<rss version="2.0"
xmlns:atom="http://www.w3.org/2005/Atom"
xmlns:isbn="http://schemas.isbn.org/ns/1999/basic.dtd"
>
<channel>
<title>Books on Example Site</title>
<link>https://example.org/books/</link>
<description>Recent content in Books on Example Site</description>
<language>en-US</language>
<atom:link href="https://example.org/books/index.xml" rel="self" type="application/rss+xml" />
<item>
<title lang="fr">The Hunchback of Notre Dame</title>
<description>Written by Victor Hugo</description>
<isbn:number>9780140443530</isbn:number>
<link>https://example.org/books/the-hunchback-of-notre-dame/</link>
<pubDate>Mon, 09 Oct 2023 09:27:12 -0700</pubDate>
<guid>https://example.org/books/the-hunchback-of-notre-dame/</guid>
</item>
<item>
<title lang="en">Les Misérables</title>
<description>Written by Victor Hugo</description>
<isbn:number>9780451419439</isbn:number>
<link>https://example.org/books/les-miserables/</link>
<pubDate>Mon, 09 Oct 2023 09:27:11 -0700</pubDate>
<guid>https://example.org/books/les-miserables/</guid>
</item>
</channel>
</rss>
```
After retrieving the remote data, inspect the data structure:
```go-html-template
<pre>{{ debug.Dump $data }}</pre>
```
Each item node looks like this:
```json
{
"description": "Written by Victor Hugo",
"guid": "https://example.org/books/the-hunchback-of-notre-dame/",
"link": "https://example.org/books/the-hunchback-of-notre-dame/",
"number": "9780140443530",
"pubDate": "Mon, 09 Oct 2023 09:27:12 -0700",
"title": {
"#text": "The Hunchback of Notre Dame",
"-lang": "fr"
}
}
```
The title keys do not begin with an underscore or a letter---they are not valid [identifiers]. Use the [`index`] function to access the values:
```go-html-template
{{ with $data.channel.item }}
<ul>
{{ range . }}
{{ $title := index .title "#text" }}
{{ $lang := index .title "-lang" }}
{{ $ISBN := .number }}
<li>{{ $title }} ({{ $lang }}) {{ $ISBN }}</li>
{{ end }}
</ul>
{{ end }}
```
Hugo renders this to:
```html
<ul>
<li>The Hunchback of Notre Dame (fr) 9780140443530</li>
<li>Les Misérables (en) 9780451419439</li>
</ul>
```
[`index`]: /functions/collections/indexfunction/
[identifiers]: https://go.dev/ref/spec#Identifiers
[resource]: /getting-started/glossary/#resource
[page bundle]: /content-management/page-bundles/
|