Framework/Helpers/WebRequestHelper.ps1

Set-StrictMode -Version Latest 
class WebRequestHelper {
   
    hidden static [string] $AzureManagementUri = "https://management.azure.com/";
    hidden static [string] $GraphApiUri = "https://graph.windows.net/";
    hidden static [string] $ClassicManagementUri = "https://management.core.windows.net/";

    static [System.Object[]] InvokeGetWebRequest([string] $uri, [Hashtable] $headers) 
    {
        return [WebRequestHelper]::InvokeWebRequest([Microsoft.PowerShell.Commands.WebRequestMethod]::Get, $uri, $headers, $null);
    }

    static [System.Object[]] InvokeGetWebRequest([string] $uri) 
    {    
        return [WebRequestHelper]::InvokeGetWebRequest($uri, [WebRequestHelper]::GetAuthHeaderFromUri($uri));
    }

    hidden static [Hashtable] GetAuthHeaderFromUri([string] $uri)
    {
        [System.Uri] $validatedUri = $null;
        if([System.Uri]::TryCreate($uri, [System.UriKind]::Absolute, [ref] $validatedUri))
        {
            return @{
                "Authorization"= ("Bearer " + [Helpers]::GetAccessToken($validatedUri.GetLeftPart([System.UriPartial]::Authority))); 
                "Content-Type"="application/json"
            };

        }
        
        return @{ "Content-Type"="application/json" };
    }

    static [System.Object[]] InvokePostWebRequest([string] $uri, [Hashtable] $headers, [System.Object] $body) 
    {
        return [WebRequestHelper]::InvokeWebRequest([Microsoft.PowerShell.Commands.WebRequestMethod]::Post, $uri, $headers, $body);
    }

    static [System.Object[]] InvokePostWebRequest([string] $uri, [System.Object] $body) 
    {
        return [WebRequestHelper]::InvokePostWebRequest($uri, [WebRequestHelper]::GetAuthHeaderFromUri($uri), $body);
    }

    static [System.Object[]] InvokeWebRequest([Microsoft.PowerShell.Commands.WebRequestMethod] $method, [string] $uri, [System.Object] $body) 
    {
        return [WebRequestHelper]::InvokeWebRequest($method, $uri, [WebRequestHelper]::GetAuthHeaderFromUri($uri), $body);
    }

    static [System.Object[]] InvokeWebRequest([Microsoft.PowerShell.Commands.WebRequestMethod] $method, [string] $uri, [Hashtable] $headers, [System.Object] $body) 
    {
       
        $outputValues = @();
        [System.Uri] $validatedUri = $null;
        while ([System.Uri]::TryCreate($uri, [System.UriKind]::Absolute, [ref] $validatedUri)) 
        {
            [int] $retryCount = 3
            $success = $false;
            while($retryCount -gt 0 -and -not $success)
            {
                $retryCount = $retryCount -1;
                try
                {
                    $requestResult = $null;
            
                    if ($method -eq [Microsoft.PowerShell.Commands.WebRequestMethod]::Get) 
                    {
                        $requestResult = Invoke-WebRequest -Method $method -Uri $validatedUri -Headers $headers -UseBasicParsing
                    }
                    elseif ($method -eq [Microsoft.PowerShell.Commands.WebRequestMethod]::Post -or $method -eq [Microsoft.PowerShell.Commands.WebRequestMethod]::Put) 
                    {
                        $requestResult = Invoke-WebRequest -Method $method -Uri $validatedUri -Headers $headers -Body ($body | ConvertTo-Json -Depth 10 -Compress)
                    }    
                    else 
                    {
                        throw [System.ArgumentException] ("The web request method type '$method' is not supported.")
                    }        
            
                    if ($null -ne $requestResult -and $requestResult.StatusCode -ge 200 -and $requestResult.StatusCode -le 399) {
                        if ($null -ne $requestResult.Content) {
                            $json = (ConvertFrom-Json $requestResult.Content)
                            if ($null -ne $json) {
                                if (($json | Get-Member -Name "value") -and $json.value) {
                                    $outputValues += $json.value;
                                }
                                else {
                                    $outputValues += $json;
                                }
                        
                                if (($json | Get-Member -Name "nextLink") -and $json.nextLink) {
                                    $uri = $json.nextLink
                                }
                                else {
                                    $uri = [string]::Empty;
                                }
                            }
                        }
                    }
                    $success = $true;
                }
                catch
                {
                    #eat the exception until it is in retry mode and throw once the retry is done
                    if($retryCount -eq 0)
                    {
                        throw;
                    }                    
                }
            }
        }

        return $outputValues;
    }

}