处理嵌套哈希以将所有值转换为字符串 [英] Process nested hash to convert all values to strings
问题描述
我有下面的代码,它接受一个散列并将所有值转换为字符串。
def stringify_values obj
@values || = obj.clone
obj.each do | k,v |
如果v.is_a?(哈希)
@values [k] = stringify_values(v)
else
@values [k] = v.to_s
end
end
return @values
end
所以给出以下散列:
{
发布:{
id:123,
text :'foobar',
}
}
YAML 输出
---& 1
:post:* 1
: id:'123'
:text:'foobar'
当我想要输出
---
:发布:
:id:'123'
:text: 'foobar'
看起来对象已经变平,然后被赋予了一个参考,导致堆栈级别错误在我的规格。
我如何得到所需的输出?
一个简单的 stringify_values
可以 - 假设它总是一个哈希。此函数使用 Hash#deep_merge
方法由Active Support Core Extensions添加 - 我们将散列与自身合并,以便在块中检查每个值并在其上调用 to_s
。
def stringify_values obj
obj.deep_merge(obj){| _,_,v | v.to_s}
end
完成工作示例:
$ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ b def stringify_values obj
obj.deep_merge(obj){| _,_,v | v.to_s}
end
class Foo
def to_s
I am Foo
end
end
h = {
post:{
id:123,
arr:[1,2,3],
text:'foobar',
obj:{ me:Foo.new}
}
}
puts YAML.dump(stringify_values h)
#=>
---
:post:
:id:'123'
:arr:[1,2,3]
:text:foobar
:obj:
:me:我是Foo
不知道期望值是多少当value是一个数组时,作为 Array#to_s
也会给你一个字符串,无论这是否合意,你可以决定并稍微调整一下解决方案。
I have the following code which takes a hash and turns all the values in to strings.
def stringify_values obj
@values ||= obj.clone
obj.each do |k, v|
if v.is_a?(Hash)
@values[k] = stringify_values(v)
else
@values[k] = v.to_s
end
end
return @values
end
So given the following hash:
{
post: {
id: 123,
text: 'foobar',
}
}
I get following YAML output
--- &1
:post: *1
:id: '123'
:text: 'foobar'
When I want this output
---
:post:
:id: '123'
:text: 'foobar'
It looks like the object has been flattened and then been given a reference to itself, which causes Stack level errors in my specs.
How do I get the desired output?
A simpler implementation of stringify_values
can be - assuming that it is always a Hash. This function makes use of Hash#deep_merge
method added by Active Support Core Extensions - we merge the hash with itself, so that in the block we get to inspect each value and call to_s
on it.
def stringify_values obj
obj.deep_merge(obj) {|_,_,v| v.to_s}
end
Complete working sample:
require "yaml"
require "active_support/core_ext/hash"
def stringify_values obj
obj.deep_merge(obj) {|_,_,v| v.to_s}
end
class Foo
def to_s
"I am Foo"
end
end
h = {
post: {
id: 123,
arr: [1,2,3],
text: 'foobar',
obj: { me: Foo.new}
}
}
puts YAML.dump (stringify_values h)
#=>
---
:post:
:id: '123'
:arr: "[1, 2, 3]"
:text: foobar
:obj:
:me: I am Foo
Not sure what is the expectation when value is an array, as Array#to_s
will give you array as a string as well, whether that is desirable or not, you can decide and tweak the solution a bit.
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