将ActiveRecord对象转储为JSON(在Rails控制台中):

pp User.first.as_json

# => {
 "id" => 1,
 "first_name" => "Polar",
 "last_name" => "Bear"
}

如果你想要处理active_record对象，puts就足够了。

例如:

没有了

2.6.0 (main):0 > User.first.to_json
  User Load (0.4ms)  SELECT  "users".* FROM "users" ORDER BY "users"."id" ASC LIMIT $1  [["LIMIT", 1]]
=> "{\"id\":1,\"admin\":true,\"email\":\"admin@gmail.com\",\"password_digest\":\"$2a$10$TQy3P7NT8KrdCzliNUsZzuhmo40LGKoth2hwD3OI.kD0lYiIEwB1y\",\"created_at\":\"2021-07-20T08:34:19.350Z\",\"updated_at\":\"2021-07-20T08:34:19.350Z\",\"name\":\"Arden Stark\"}"

与使

2.6.0 (main):0 > puts User.first.to_json
  User Load (0.3ms)  SELECT  "users".* FROM "users" ORDER BY "users"."id" ASC LIMIT $1  [["LIMIT", 1]]
{"id":1,"admin":true,"email":"admin@gmail.com","password_digest":"$2a$10$TQy3P7NT8KrdCzliNUsZzuhmo40LGKoth2hwD3OI.kD0lYiIEwB1y","created_at":"2021-07-20T08:34:19.350Z","updated_at":"2021-07-20T08:34:19.350Z","name":"Arden Stark"}
=> nil

如果你处理json数据，json。Pretty_generate是一个很好的替代方案

例子:

obj = {foo: [:bar, :baz], bat: {bam: 0, bad: 1}}
json = JSON.pretty_generate(obj)
puts json

输出:

{
  "foo": [
    "bar",
    "baz"
  ],
  "bat": {
    "bam": 0,
    "bad": 1
  }
}

如果是在ROR项目中，我总是喜欢使用gem pry-rails在rails控制台中格式化我的代码，而不是awesome_print，这太冗长了。

撬轨的例子:

它还有语法高亮显示。

如果你正在使用RABL，你可以使用JSON.pretty_generate来配置它:

class PrettyJson
  def self.dump(object)
    JSON.pretty_generate(object, {:indent => "  "})
  end
end

Rabl.configure do |config|
  ...
  config.json_engine = PrettyJson if Rails.env.development?
  ...
end

使用JSON的一个问题。pretty_generate是JSON模式验证器将不再满意您的datetime字符串。你可以在config/initializers/rabl_config中修正这些问题。rb:

ActiveSupport::TimeWithZone.class_eval do
  alias_method :orig_to_s, :to_s
  def to_s(format = :default)
    format == :default ? iso8601 : orig_to_s(format)
  end
end

使用pretty_generate()函数，该函数内置于JSON的后期版本中。例如:

require 'json'
my_object = { :array => [1, 2, 3, { :sample => "hash"} ], :foo => "bar" }
puts JSON.pretty_generate(my_object)

这就得到了:

{
  "array": [
    1,
    2,
    3,
    {
      "sample": "hash"
    }
  ],
  "foo": "bar"
}

看看Awesome Print吧。将JSON字符串解析为Ruby Hash，然后用ap显示它，如下所示:

require "awesome_print"
require "json"

json = '{"holy": ["nested", "json"], "batman!": {"a": 1, "b": 2}}'

ap(JSON.parse(json))

通过以上，你会看到:

{
  "holy" => [
    [0] "nested",
    [1] "json"
  ],
  "batman!" => {
    "a" => 1,
    "b" => 2
  }
}

Awesome Print还会添加一些Stack Overflow无法显示的颜色。

如果您希望在Rails控制器动作中快速实现此功能以发送JSON响应:

def index
  my_json = '{ "key": "value" }'
  render json: JSON.pretty_generate( JSON.parse my_json )
end