Updated example to use current syntax

Draft/RealTime-Parameter-Bind.md

@@ -22,46 +22,107 @@ Facilitate PowerShell's dynamic parameter block by allowing `RuntimeDefinedParam
 
 Suppose a user wants to interactively install different versions of Microsoft Edge, filtered by Product, Platform, and Architecture. With this proposed change, once the user selects a Product, the subsequent options for Platform are filtered based on that selection. Once a Platform is selected, the Architecture choices are then filtered, and so forth. 
 
-The sample code below demonstrates how this experience might look with the proposed changes:
+The sample code below demonstrates how this experience _might_ look with the proposed changes:
 
 ```powershell
-param()
-dynamicparam
-{   
-    New-ParameterCollection -Parameters @(
-        $EdgeVersions = Invoke-RestMethod https://edgeupdates.microsoft.com/api/products
-        New-RuntimeDefinedParameter -Name Product -ValidValues $EdgeVersions.Product -Type ([string]) -Mandatory      
-        if($Product)
-        {
-            $EdgeVersions = $EdgeVersions | ?{$_.Product -eq $Product}
-        }
-        $Platforms = $EdgeVersions | %{ $_.Releases } | select -Unique -Expand Platform 
-        New-RuntimeDefinedParameter -Name Platform -ValidValues $Platforms -Type ([string]) -Mandatory   
-        if($Platform)
-        {
-            $EdgeVersions = $EdgeVersions | ?{$_.Releases.Platform -eq $Platform}                
-        }
+$EdgeVersions = Invoke-RestMethod https://edgeupdates.microsoft.com/api/products
+
+$productParamAttributes = [Collection[Attribute]]@( 
+    ([ValidateSet]::new($EdgeVersions.Product)),
+    ([Parameter]@{ Mandatory = $true })
+)
+[RuntimeDefinedParameter]::new('Product', [string], $productParamAttributes)
+
+if($Product)
+{
+    $EdgeVersions = $EdgeVersions | ?{$_.Product -eq $Product}
+    $Platforms = $EdgeVersions | %{ $_.Releases } | select -Unique -Expand Platform 
+
+    $platformParamAttributes = [Collection[Attribute]]@( 
+        ([ValidateSet]::new($Platforms)),
+        ([Parameter]@{ Mandatory = $true })
+    )
+    [RuntimeDefinedParameter]::new('Platform', [string], $platformParamAttributes)
+
+    if($Platform)
+    {
+        $EdgeVersions = $EdgeVersions | ?{$_.Releases.Platform -eq $Platform}                
         $Architectures = $EdgeVersions.Releases.Architecture | select -Unique | sort
-        New-RuntimeDefinedParameter -Name Architecture -ValidValues $Architectures -Type ([string]) -Mandatory 
+
+        $architectureParamAttributes = [Collection[Attribute]]@( 
+            ([ValidateSet]::new($Architectures)),
+            ([Parameter]@{ Mandatory = $true })
+        )
+        [RuntimeDefinedParameter]::new('Architecture', [string], $architectureParamAttributes)
+
         if($Architecture)
         {
-            $EdgeVersions = $EdgeVersions | ?{$_.Releases.Architecture -eq $Architecture}                
+            $EdgeVersions = $EdgeVersions | ?{$_.Releases.Architecture -eq $Architecture}
+            $versionToInstallValues = $EdgeVersions.Releases.ProductVersion | select -Unique
+
+            $versionParamAttributes = [Collection[Attribute]]@( 
+                ([ValidateSet]::new($versionToInstallValues)),
+                ([Parameter]@{ Mandatory = $true })
+            )
+            [RuntimeDefinedParameter]::new('Version', [string], $versionParamAttributes)
         }
-        New-RuntimeDefinedParameter -Name VersionToInstall -ValidValues ($EdgeVersions.Releases.ProductVersion | select -Unique) -Type ([string])  -Mandatory           
-    )    
-}
-end
-{
+    }
 }
 ```
-
 Upon execution, users will be prompted incrementally:
 
 ```output
 Product: [List of Products]
 Platform: [Filtered List of Platforms]
 Architecture: [Filtered List of Architectures]
-VersionToInstall: [Filtered List of Versions]
+Version: [Filtered List of Versions]
+```
+
+The syntax could be even more concise with user-supplied helper function `New-Parameter`
+```powershell
+function New-Parameter {
+    param(
+        [string]$Name,
+        [Type]$Type = [object],
+        [string[]]$ValidValues,
+        [switch]$Mandatory
+    )
+
+    $attributes = [Collection[Attribute]]@(
+        ([ValidateSet]::new($ValidValues)),
+        ([Parameter]@{ Mandatory = $Mandatory })
+    )
+
+    return [RuntimeDefinedParameter]::new($Name, $Type, $attributes)
+}
+
+Function Get-EdgeUpdates
+{
+    param()
+    dynamicparam
+    {   
+        $EdgeVersions = Invoke-RestMethod https://edgeupdates.microsoft.com/api/products
+        New-Parameter -Name Product -ValidValues $EdgeVersions.Product -Type ([string]) -Mandatory      
+        if($Product)
+        {
+            $EdgeReleases = $EdgeVersions | ?{$_.Product -eq $Product} | select -Expand Releases # Beta,Stable,Dev,Canary
+            New-Parameter -Name Platform -ValidValues ($EdgeReleases.Platform | select -Unique) -Type ([string]) -Mandatory # Windows,Linux,MacOS,Android
+            if($Platform)
+            {
+                $EdgeReleases = $EdgeReleases | ?{$_.Platform -eq $Platform}                
+                New-Parameter -Name Architecture -ValidValues ($EdgeReleases.Architecture | select -Unique) -Type ([string]) -Mandatory # x86,x64,arm64,universal
+                if($Architecture)
+                {
+                    $EdgeReleases = $EdgeReleases | ?{$_.Architecture -eq $Architecture}                
+                    New-Parameter -Name Version -ValidValues ($EdgeReleases.ProductVersion | select -Unique) -Type ([string]) -Mandatory    
+                }
+            }
+        }
+    }
+    end
+    {
+    }
+}
 ```
 
 ## Specification