transform.Unmarshal

语法

transform.Unmarshal [OPTIONS] INPUT

返回值

any

别名

unmarshal

输入可以是字符串或资源。

解组字符串

{{ $string := `
title: Les Misérables
author: Victor Hugo
`}}

{{ $book := unmarshal $string }}
{{ $book.title }} → Les Misérables
{{ $book.author }} → Victor Hugo

解组资源

将 transform.Unmarshal 函数与全局、页面和远程资源一起使用。

全局资源

全局资源是 assets 目录中的文件，或任何挂载到 assets 目录的目录中的文件。

assets/
└── data/
    └── books.json

{{ $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 }}

页面资源

页面资源是页面包中的文件。

content/
├── post/
│   └── book-reviews/
│       ├── books.json
│       └── index.md
└── _index.md

{{ $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 }}

远程资源

远程资源是位于远程服务器上的文件，可通过 HTTP 或 HTTPS 访问。

{{ $data := dict }}
{{ $url := "https://example.org/books.json" }}
{{ with try (resources.GetRemote $url) }}
  {{ with .Err }}
    {{ errorf "%s" . }}
  {{ else with .Value }}
    {{ $data = . | transform.Unmarshal }}
  {{ else }}
    {{ errorf "Unable to get remote resource %q" $url }}
  {{ end }}
{{ end }}

{{ range where $data "author" "Victor Hugo" }}
  {{ .title }} → Les Misérables
{{ end }}

选项

当解组 CSV 文件时，请提供可选的选项映射。

delimiter: (string) 使用的分隔符，默认为 ,。
comment: (string) CSV 中使用的注释字符。如果设置，则忽略不带前导空格的注释字符开头的行。
lazyQuotes v0.122.0 新增: (bool) 如果为 true，则引号可能出现在未加引号的字段中，并且未加倍的引号可能出现在加引号的字段中。默认为 false。

{{ $csv := "a;b;c" | transform.Unmarshal (dict "delimiter" ";") }}

使用 XML

当解组 XML 文件时，访问数据时不要包含根节点。例如，在解组下面的 RSS 源后，使用 $data.channel.title 访问源标题。

<?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>

获取远程数据

{{ $data := dict }}
{{ $url := "https://example.org/books/index.xml" }}
{{ with try (resources.GetRemote $url) }}
  {{ with .Err }}
    {{ errorf "%s" . }}
  {{ else with .Value }}
    {{ $data = . | transform.Unmarshal }}
  {{ else }}
    {{ errorf "Unable to get remote resource %q" $url }}
  {{ end }}
{{ end }}

检查数据结构

<pre>{{ debug.Dump $data }}</pre>

列出书名

{{ with $data.channel.item }}
  <ul>
    {{ range . }}
      <li>{{ .title }}</li>
    {{ end }}
  </ul>
{{ end }}

Hugo 将其渲染为

<ul>
  <li>The Hunchback of Notre Dame</li>
  <li>Les Misérables</li>
</ul>

XML 属性和命名空间

让我们向 RSS 源的 title 节点添加 lang 属性，并为 ISBN 号添加命名空间节点

<?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="en">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="fr">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>

检索远程数据后，检查数据结构

<pre>{{ debug.Dump $data }}</pre>

每个 item 节点如下所示

{
  "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": "en"
  }
}

标题键不是以下划线或字母开头，它们不是有效的标识符。使用 index 函数访问值

{{ with $data.channel.item }}
  <ul>
    {{ range . }}
      {{ $title := index .title "#text" }}
      {{ $lang := index .title "-lang" }}
      {{ $ISBN := .number }}
      <li>{{ $title }} ({{ $lang }}) {{ $ISBN }}</li>
    {{ end }}
  </ul>
{{ end }}