/// <summary>
/// Helper method to do additional transformation on the output value.
/// </summary>
internal static object TransformOutBindingValueAsNeeded(string bindingName, ReadOnlyBindingInfo bindingInfo, object value)
{
switch (bindingInfo.Type)
{
case "http":
// Try converting the value to HttpResponseContext if it's not already an object of such type.
if (value is HttpResponseContext)
{
break;
}
try
{
value = LanguagePrimitives.ConvertTo <HttpResponseContext>(value);
}
catch (PSInvalidCastException ex)
{
string errorMsg = string.Format(PowerShellWorkerStrings.FailToConvertToHttpResponseContext, bindingName, ex.Message);
throw new InvalidOperationException(errorMsg);
}
break;
default:
break;
}
return(value);
}
/// <summary>
/// Helper private function that maps an output binding to a data collecting behavior.
/// </summary>
private DataCollectingBehavior GetDataCollectingBehavior(ReadOnlyBindingInfo bindingInfo)
{
switch (bindingInfo.Type)
{
case "http": return(DataCollectingBehavior.Singleton);
case "blob": return(DataCollectingBehavior.Singleton);
case "sendGrid": return(DataCollectingBehavior.Singleton);
case "onedrive": return(DataCollectingBehavior.Singleton);
case "outlook": return(DataCollectingBehavior.Singleton);
case "notificationHub": return(DataCollectingBehavior.Singleton);
case "excel": return(DataCollectingBehavior.Collection);
case "table": return(DataCollectingBehavior.Collection);
case "queue": return(DataCollectingBehavior.Collection);
case "eventHub": return(DataCollectingBehavior.Collection);
case "documentDB": return(DataCollectingBehavior.Collection);
case "mobileTable": return(DataCollectingBehavior.Collection);
case "serviceBus": return(DataCollectingBehavior.Collection);
case "signalR": return(DataCollectingBehavior.Collection);
case "twilioSms": return(DataCollectingBehavior.Collection);
case "graphWebhookSubscription": return(DataCollectingBehavior.Collection);
// Be conservative on new output bindings
default: return(DataCollectingBehavior.Singleton);
}
}
/// <summary>
/// Helper method to do additional transformation on the input value based on the type constraints specified in the script.
/// </summary>
internal static object TransformInBindingValueAsNeeded(PSScriptParamInfo paramInfo, ReadOnlyBindingInfo bindingInfo, object value)
{
switch (bindingInfo.Type)
{
case "blob":
case "blobTrigger":
// For blob input, the input data could be an array of bytes or a string. Documentation says
// that a user can specify the 'dataType' to make the input data of the expected type. (see
// https://docs.microsoft.com/en-us/azure/azure-functions/functions-triggers-bindings#binding-datatype-property)
//
// However, I found this setting is somewhat broken:
// 1. For the 'blobTrigger' type in-binding, the input data is always byte array and the host doesn't
// respect the "dataType" setting in 'function.json'.
// 2. For the 'blob' type in-binding, the input data type is 'String' by default. When specified, the
// 'binary' and 'string' dataType are respected, but 'stream' dataType is not respected.
//
// Due to (1), we should be reasonably smart and transform the data appropriately when type constraint is
// specified on the input parameter to indicate the expected data type.
Type paramType = paramInfo.ParamType;
if (value is byte[] blobBytes)
{
if (paramType == typeof(string))
{
// String is expected, so convert the byte array to string using UTF8 encoding.
// This is a best effort attempt, as we don't know the true encoding.
value = Encoding.UTF8.GetString(blobBytes);
}
else if (paramType == typeof(Stream))
{
// Stream is expected, so convert the byte array to a MemoryStream.
value = new MemoryStream(blobBytes);
}
}
// When the input is 'String', we don't attempt to convert it to bytes because if the blob
// is in fact a binary file, it's impossible to get the right bytes back even if we use the
// same encoding used by the host when converting those bytes to string.
break;
default:
break;
}
return(value);
}
/// <summary>
/// BeginProcessing override.
/// </summary>
protected override void BeginProcessing()
{
_bindingInfo = GetBindingInfo(Name);
_behavior = GetDataCollectingBehavior(_bindingInfo);
_outputBindings = FunctionMetadata.GetOutputBindingHashtable(Runspace.DefaultRunspace.InstanceId);
}
