tables-reflection.fsx

#r "nuget:WindowsAzure.Storage"

open Microsoft.WindowsAzure.Storage.Table

type Isaac = { Name : string; Age : int }

let typeCache = System.Collections.Generic.Dictionary()

let addToCache<'T>() =
    let theType = typeof<'T>
    let ctor = theType.GetConstructors().[0]
    let parameters = ctor.GetParameters()
    typeCache.Add(theType, {| Ctor = ctor; Parameters = parameters |})

let getOrAddFromCache<'T>() =
    match typeCache.TryGetValue typeof<'T> with
    | true, cache -> cache
    | false, _ -> addToCache<'T>(); typeCache.[typeof<'T>]

let buildRecordFromEntity<'T> (entity:DynamicTableEntity) =    
    let cache = getOrAddFromCache<'T>()
    let args = [|
        for p in cache.Parameters do
            entity.Properties.[p.Name].PropertyAsObject
    |]
    cache.Ctor.Invoke(args) :?> 'T

let buildRecordFromEntityNoCache<'T> (entity:DynamicTableEntity) =    
    let theType = typeof<'T>
    let ctor = theType.GetConstructors().[0]
    let parameters = ctor.GetParameters()
    let args = [|
        for p in parameters do
            entity.Properties.[p.Name].PropertyAsObject
    |]
    ctor.Invoke(args) :?> 'T

let isaacTable =
    DynamicTableEntity("PK1", "RK1", "", dict [ "name", EntityProperty.GeneratePropertyForString "Isaac"; "age", EntityProperty.GeneratePropertyForInt 41 ])

isaacTable |> buildRecordFromEntityNoCache<Isaac>