Swift Keypath from String

Question

Is there a way to create a Keypath from a String in Swift 4 to access a value in a struct by its path or variable name

Finally I found out that I should use CodingKeys instead of KeyPaths to access the a value of a variable of a struct by String

Thanks in advance, Michael

can you add example code on what you are trying to do what to expect ? — Mohmmad S, Sep 20 '18 at 14:29
I want to convert a String like 'sensor.temp.1' to a Keypath to access a value in nested strucures. I dont want to hardcode this Keypath to make the path to the value runtime-configurable — Michael_mhr, Sep 20 '18 at 14:31
Just a simple struct, that contains another struct in a variable, that contains the values as Int... Nothing special... — Michael_mhr, Sep 20 '18 at 14:37
when you say "Finally I found out that I should use CodingKeys instead of KeyPaths to access the a value of a variable of a struct by String" do you have a reference for this? How did you achieve that? — Olympiloutre, Jul 25 '19 at 01:34

score -1 · Accepted Answer · answered Sep 20 '18 at 14:49

-1

consider you have something like this,

struct foo {

var test: doo

}

struct doo {

var test: Int

}
 //How to use it 

    let doo = Doo(test: 10)
    let foo = Foo(test: doo)

    let mykeyPath = \Foo.test.test

    let result = foo[keyPath: mykeyPath]

    print(result)

answered Sep 20 '18 at 14:49

Mohmmad S

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Is there I way to get the KeyPath from String to make it runtime-configurable? – Michael_mhr Sep 20 '18 at 15:35
this is how to use keypath with structs so any value changing the keypath accessing remain the same i don't really understand what you mean by "KeyPath from String to make it runtime-configurable" – Mohmmad S Sep 20 '18 at 15:37
I want to create a KeyPath from String. For example the String contains 'sensors.temperature.temp1' I will get the (Optional) value of the variable in the nested struct with the name 'temp1' – Michael_mhr Sep 20 '18 at 15:42
Coding Keys ? thats something else – Mohmmad S Sep 20 '18 at 15:43
edit your question add the structs and be clear KeyPath, is not Coding Keys , if you are trying to access something with KeyPath thats how thats the correct answer if you want to decode something into another things using structs thats called Coding Keys – Mohmmad S Sep 20 '18 at 15:45
try the code above, in your case make sure to understand it too – Mohmmad S Sep 20 '18 at 15:46
I haven't heard about CodingKeys and searched for KeyPath instead... I will close this question, because there are already many questions to this thematic out there. Thank you very much for your time answering this senseless question.. – Michael_mhr Sep 20 '18 at 15:53
Would you close or delete it? – Michael_mhr Sep 20 '18 at 15:54
i would leave it, other people may find it helpful :) either the answer or the question, personally i marked as fav – Mohmmad S Sep 20 '18 at 15:56

Swift Keypath from String

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