Deserializing YAML using YamlDotNet when the root node of each object is named using it's ID?

Question

I'm using C# and I have a YAML file I want to deserialize.

I've looked at using YamlDotNet, and it looks like it's pretty decent, but I can't find how to handle this situation.

The YAML text I am working with has the following format:

1:
    id: 1
    name: foo
2:
    id: 2
    name: foo

I wish it looked like this instead, but it doesn't:

- id: 1
  name: foo
- id: 2
  name: foo

I can of course revert to doing everything much more manually, by looping over each node and manually creating the data object instances, but it seems like there should still be a way to have the ease of use from YamlDotNet while handling this annoying data structure.

I'm open to suggestions for other YAML parsing libraries in .NET.

Your ideal format is not a valid YAML file, you cannot have two keys with the same value in one mapping. More appropriate would be a toplevel sequence with mappings as elements — Anthon, Dec 14 '16 at 15:47
@Anthon Fair point! As you can probably tell I don't know much about YAML. — , Dec 14 '16 at 15:49
Would it be of interest to rewrite/reformat the file. Using Python and ruamel.yaml (of which I am the author), that is trivial, even preserving comments after the original key-value pairs. You could even call the python program to do the preprocessing from your C# code. — Anthon, Dec 14 '16 at 19:38
Thanks for the suggestion, it's certainly an option. I found, and Antoine Aubry suggested, tweaks to the deserialization objects that will handle my case and I feel they're a better option for what I'm doing. But I'll keep ruamel.yaml in mind if I have YAML issues to solve in the future. — , Dec 15 '16 at 10:41

score 6 · Accepted Answer · edited May 23 '17 at 11:45

6

I found the answer in another SO question: Seeking guidance reading .yaml files with C#

By deserializing to Dictionary<int, Item> I can successfully handle this data structure.

deserializer.Deserialize<Dictionary<int, Item>>(textReader);

edited May 23 '17 at 11:45

Community

1
1

answered Dec 14 '16 at 16:09

score 3 · Answer 2 · answered Dec 14 '16 at 22:10

3

If you use a list, as your edit, you can deserialize that file easily using code similar to this:

class MyObject {
    public int Id { get; set; }
    public string Name { get; set; }
}

var deserializer = new DeserializerBuilder()
     .WithNamingConvention(new CamelCaseNamingConvention())
     .Build();

var result = deserializer.Deserialize<List<MyObject>>(File.OpenText("myfile.yml"));

Note: I am typing on a phone and can't test the code. It should be mostly correct but I haven't tested it.

answered Dec 14 '16 at 22:10

Antoine Aubry

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I tried deserializing to a `List<>` but I got the following exception: `Additional information: (Line: 1, Col: 1, Idx: 0) - (Line: 1, Col: 1, Idx: 0): Expected 'SequenceStart', got 'MappingStart' (at Line: 1, Col: 1, Idx: 0).` Deserializing to a Dictionary<> works though ... which is what you suggested in the other thread I found. So thank you! If you want to change this to using `Dictionary<>` I'll happily delete my answer and accept yours (since you're the original source anyway). – Dec 15 '16 at 11:12
The List<> is for your updated code, which is more appropriate to represent that information: `- id: 1 name: foo - id: 2 name: foo` – Antoine Aubry Dec 15 '16 at 23:04
My ideal data is what I wish I had, but I don't have it. I'm stuck with the data the way it is. Well, not stuck, but I'd rather use Dictionary<> than mess about with transforming the data. – Dec 16 '16 at 08:35

Deserializing YAML using YamlDotNet when the root node of each object is named using it's ID?

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