如何使用文字标量样式在 YAML 中转储字符串? [英] How to dump strings in YAML using literal scalar style?

问题描述

我有一大串格式化数据(例如 JSON)，我想在 ruby​​ 中使用 Psych 转储到 YAML同时保留格式.

I have a big string of formatted data (e.g. JSON) that I want to dump to YAML using Psych in ruby while preserving formatting.

基本上，我希望 JSON 使用 文字样式:

Basically, I want for JSON to appear in YAML using literal style:

---
json: |
  {
    "page": 1,
    "results": [
      "item", "another"
    ],
    "total_pages": 0
  }

但是，当我使用 YAML.dump 时，它不使用文字样式.我得到这样的东西:

However, when I use YAML.dump it doesn't use literal style. I get something like this:

---
json: ! "{
  "page": 1,
  "results": [
    "item", "another"
  ],
  "total_pages":
  0
}
"

我怎样才能告诉 Psych 以想要的样式转储标量?

How can I tell Psych to dump scalars in wanted style?

非常感谢 Aaron Patterson 的解决方案，我在此扩展:https://gist.github.com/2023978

Big thanks to Aaron Patterson for his solution that I'm expanding on here: https://gist.github.com/2023978

虽然有点冗长，但该要点是一种在 ruby​​ 中标记某些字符串以使用 YAML 中的文字样式输出的工作方式.

Although a bit verbose, that gist is a working way of tagging certain strings in ruby to be output using literal style in YAML.

推荐答案

require 'psych'

# Construct an AST
visitor = Psych::Visitors::YAMLTree.new({})
visitor << DATA.read
ast = visitor.tree

# Find all scalars and modify their formatting
ast.grep(Psych::Nodes::Scalar).each do |node|
  node.plain  = false
  node.quoted = true
  node.style  = Psych::Nodes::Scalar::LITERAL
end

begin
  # Call the `yaml` method on the ast to convert to yaml
  puts ast.yaml
rescue
  # The `yaml` method was introduced in later versions, so fall back to
  # constructing a visitor
  Psych::Visitors::Emitter.new($stdout).accept ast
end

__END__
{
  "page": 1,
  "results": [
    "item", "another"
],
  "total_pages": 0
}

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