转换红宝石结构来YAML

Question

我有红宝石一个结构，看起来像这样：

Struct.new("Device", :brand, :model, :port_id) 
@devices = [ 
Struct::Device.new('Apple', 'iphone5', 3), 
Struct::Device.new('Samsung', 'Galaxy S4', 1) 
] 

转换这个to_yaml给了我这样的结果：

--- 
- !ruby/struct:Struct::Device 
    brand: Apple 
    model: iphone5 
    port_id: 3 
- !ruby/struct:Struct::Device 
    brand: Samsung 
    model: Galaxy S4 
    port_id: 1 

但是我仍然不知道如何当我需要在我的代码中使用它时，将我的结构从yaml转换回来。当我在yaml代码的顶部添加devices:，然后尝试从CONFIG ['devices']变量解析回ruby结构 - 我没有得到任何结果。

任何帮助将不胜感激！

Answer 1

我没有看到你的问题：

irb(main):001:0> require 'yaml' 
=> true 
irb(main):002:0> Struct.new("Device", :brand, :model, :port_id) 
=> Struct::Device 
irb(main):003:0> devices = [ 
irb(main):004:1* Struct::Device.new('Apple', 'iphone5', 3), 
irb(main):005:1* Struct::Device.new('Samsung', 'Galaxy S4', 1) 
irb(main):006:1> ] 
=> [#<struct Struct::Device brand="Apple", model="iphone5", port_id=3>, #<struct Struct::Device brand="Samsung", model="Galaxy S4", port_id=1>] 
irb(main):007:0> y = devices.to_yaml 
=> "---\n- !ruby/struct:Struct::Device\n brand: Apple\n model: iphone5\n port_id: 3\n- !ruby/struct:Struct::Device\n brand: Samsung\n model: Galaxy S4\n port_id: 1\n" 
irb(main):008:0> obj = YAML::load(y) 
=> [#<struct Struct::Device brand="Apple", model="iphone5", port_id=3>, #<struct Struct::Device brand="Samsung", model="Galaxy S4", port_id=1>] 

你必须确保在YAML::load前Struct.new运行以及前.to_yaml。否则，Ruby不知道如何从文本创建结构。

好吧，正如我所说的，您必须在尝试加载之前运行Struct定义。另外，您正在试图建立一个哈希，所以使用YAML语法：

config.yml：

--- 
devices: 
- !ruby/struct:Struct::Device 
    brand: Apple 
    model: iphone5 
    port_id: 3 
- !ruby/struct:Struct::Device 
    brand: Samsung 
    model: Galaxy S4 
    port_id: 1 

而且test.rb：

require 'yaml' 
Struct.new("Device", :brand, :model, :port_id) 
CONFIG = YAML::load_file('./config.yml') unless defined? CONFIG 
devices = CONFIG['devices'] 
puts devices.inspect 

结果：

C:\>ruby test.rb 
[#<struct Struct::Device brand="Apple", model="iphone5", port_id=3>, #<struct Struct::Device brand="Samsung", model="Galaxy S4", port_id=1>]