Hello @yaya,
thank you for reaching out to us. Your example does build for me in R23, at least regarding the mentioned line of code:
const maxon::InputStreamRef inputStream = webFile.OpenInputStream() iferr_return;
Your example is however incomplete, it is missing the include statement to include iostreams.h which is likely causing your error. But there should be more errors for you in this stretch of code, since for example the line const maxon::Url webFile = (maxon::Url("https://www.mysite.com/Somevideo.mp4"_s))iferr_return is also incorrect. Find a commented example at the end of my posting for details.
On SDK help search there is no a link to a "InputStreamRef".
The maxon API does provide in C++ a managed memory environment, i.e., garbage collection, akin to managed languages like C# or Python. Which means all objects are split into the actual object instance and references to that instance. The object instance is then reference counted and deallocated once there are no references to it anymore. So, when you have a ThingRef, it is actually just a reference to an instance of a ThingInterface (at least most of the time, copy-on-write object references do not have the Ref postfix, i.e., the reference for a COW ThingInterface would be called Thing). The Doxygen parser (the tool we are using for documentation) does struggle heavily with all the metaprogramming we do and cannot properly ingest Ref entities. This is a bit tricky subject we are aware of and working on to, but this will take some time.
Long story short, you would have to search here for InputStreamInterface. There is also our Entity Creation Manual which does expand a bit on the topic of interfaces and their references.
If you continue to have problems, please make sure to post your full code and not just a snippet, as it otherwise mostly guesswork for us to figure out where your problem lies.
Cheers,
Ferdinand
// You must include this header in order to have access to the full interface definitions.
#include "maxon\iostreams.h"
maxon::Result<void> SomeFunction()
{
iferr_scope;
// The iferr_return here was incorrect. In our example it is required because we concatenate there
// two urls. UrlInterface.operator+ is a maxon::Result, i.e., requires error handling. Just
// initializing a Url does not have any error handling and therefor requires no iferr_return.
const maxon::Url url("https://www.mysite.com/Somevideo.mp4"_s);
const maxon::UrlScheme scheme = url.GetScheme();
const maxon::Bool isHTTP = scheme == maxon::URLSCHEME_HTTP;
const maxon::Bool isHTTPS = scheme == maxon::URLSCHEME_HTTPS;
if (isHTTP || isHTTPS)
{
const maxon::InputStreamRef inputStream = url.OpenInputStream() iferr_return;
const maxon::Int length = inputStream.GetStreamLength() iferr_return;
maxon::BaseArray<maxon::Char> data;
data.Resize(length) iferr_return;
inputStream.Read(data) iferr_return;
inputStream.Close() iferr_return;
// trgetUrl was not defined in your/our example, so I did redefine it here as someUrl.
const maxon::Url someUrl("https://www.yoursite.com/"_s);
// This will be "https://www.yoursite.com/Somevideo.mp4", i.e., GetName returns the last
// component of a Url, e.g., "Somevideo.mp4" in this case. Here we need the iferr_return, since
// UrlInterface.operator+ can fail, i.e., return an error.
const maxon::Url anotherUrl = (someUrl + url.GetName()) iferr_return;
const maxon::OutputStreamRef outputStream = anotherUrl.OpenOutputStream() iferr_return;
outputStream.Write(data) iferr_return;
outputStream.Close() iferr_return;
}
return maxon::OK;
}
