F# Yaml type provider

Question

I have tried using a Yaml collection of maps in my config file :

Companies:
  - code: 11
    name: A
    country: FR
    functionalCurrency: EUR
  - code: 12
    name: B
    country: GB
    functionalCurrency: GBP

However, when trying to read it with the type provider, it only finds the first result of the list.

With :

  open FSharp.Configuration
  type CompaniesConfig = YamlConfig<"Config.yaml">  
  let config = CompaniesConfig()

the output is :

  val config : CompaniesConfig =
    Companies:
    - code: 11
      name: A
      country: FR
      functionalCurrency: EUR

Trying to parse the code online worked, hence I wonder if that is a library limitation or... ?

Thanks for your help

Answer 1

You need to actually load the file, not only get the schema if you want to work with it directly: config.Load(yamlFile). This should probably more explicit in the documentation. I used the sample file in the link.

#if INTERACTIVE
#r @"..\packages\FSharp.Configuration.0.6.1\lib\net40\FSharp.Configuration.dll"
#endif

open FSharp.Configuration
open System.IO

/// https://github.com/fsprojects/FSharp.Configuration/blob/master/tests/FSharp.Configuration.Tests/Lists.yaml

[<Literal>]
let yamlFile = __SOURCE_DIRECTORY__ + "..\Lists.yaml"

File.Exists yamlFile

type TestConfig = YamlConfig<yamlFile>
let config = TestConfig()

config.Load(yamlFile)
config.items.Count
config.items

And I get both items:

> 
val it : int = 2
> 
val it : System.Collections.Generic.IList<TestConfig.items_Item_Type> =
  seq
    [FSharp.Configuration.TestConfig+items_Item_Type
       {descrip = "Water Bucket (Filled)";
        part_no = "A4786";
        price = 147;
        quantity = 4;};
     FSharp.Configuration.TestConfig+items_Item_Type
       {descrip = "High Heeled "Ruby" Slippers";
        part_no = "E1628";
        price = 10027;
        quantity = 1;}]
>