Url Manual
A maxon::Url defines the location of a file or a similar resource. The class allows to construct a file path and to handle files. maxon::Url is based on maxon::UrlInterface .
A maxon::Url can be constructed with:
// start file scheme on drive C maxon::Url url { "file:///c:" _s };
// add folder url.Append( "folder" _s) iferr_return ;
// add file url = (url + "file.txt" _s) iferr_return ;
// print result DiagnosticOutput ( "Full URL: @" , url);
Various default folders can be obtained from the maxon::Application class:
另请参阅 Application Manual .
An URL can reference files on the file system, web addresses, files within ZIP files, etc. The scheme defines what kind of object a given maxon::Url is referencing:
The supported maxon::UrlScheme types are:
An maxon::Url is composed of several parts. These parts can be accessed individually:
// get authority and directory; no format statement applied const maxon::String authority = url.GetAuthority().ToString( nullptr ); const maxon::String directory = url.GetDirectory().ToString( nullptr ); const maxon::String name = url.GetName(); const maxon::String suffix = url.GetSuffix(); DiagnosticOutput ( "URL Parts: @, @, @, @" , authority, directory, name, suffix);
The maxon::Url class contains several functions to analyse and handle files:
// check if folder does not exit if (workFolder.IoDetect() == maxon::IODETECT::NONEXISTENT ) { // create folder workFolder.IoCreateDirectory( true ) iferr_return ; }
// show folder workFolder.IoShowInOS( maxon::IOSHOWINOSFLAGS::SHOW_IN_EXPLORER ) iferr_return ;
// This example checks the files of the given folder. // If a file is of a certain type (suffix "exr") it is moved to a sub-folder.
// check if folder exists if (renderFolder.IoDetect() != maxon::IODETECT::DIRECTORY ) return maxon::OK ;
// create sub-folder const maxon::Url exrFolder = (renderFolder + "exr" _s) iferr_return ; exrFolder.IoCreateDirectory( true ) iferr_return ;
// move all *.exr files to sub-folder for ( const auto & it : renderFolder.GetBrowseIterator( maxon::GETBROWSEITERATORFLAGS::NONE )) { const maxon::IoBrowseRef& browseDirectory = (it) iferr_return ; const maxon::Url url = browseDirectory.GetCurrentPath();
// check if element is a file if (url.IoDetect() != maxon::IODETECT::FILE ) continue ;
// check if *.exr file if (url.CheckSuffix( "exr" _s)) { // construct target file name const maxon::Url targetFile = (exrFolder + url.GetName()) iferr_return ; DiagnosticOutput ( "Move file @ to @" , url, targetFile); // move file url.IoMove(targetFile) iferr_return ; } }
Data streams are used to write into and read from a resource defined with a maxon::Url :
另请参阅 maxon::IoFileOutputHelper and maxon::IoFileInputHelper .
For details on input/output streams see InputStream Manual and OutputStream Manual .
// This example opens a simple text file and prints the content to the console. // After that, additional text is added to the file.// construct file URL const maxon::Url logFile = (targetFolder + maxon::Url ( "log.txt" _s)) iferr_return ;
// read file if it exists if (logFile.IoDetect() == maxon::IODETECT::FILE ) { // read data maxon::BaseArray<maxon::Char> fileData; maxon::FileUtilities::ReadFileToMemory (logFile, fileData) iferr_return ;
// to maxon::String const maxon::String fileString { fileData }; DiagnosticOutput ( "Log Content: @" , fileString); }
// output string const maxon::String logData { "logged event..\r\n" }; const maxon::BaseArray<maxon::Char> logDataMem = logData.GetCString() iferr_return ;
// write using stream const auto flags = maxon::OPENSTREAMFLAGS::WRITE_DONT_TRUNCATE | maxon::OPENSTREAMFLAGS::SEEK_TO_END ; const maxon::OutputStreamRef stream = logFile.OpenOutputStream(flags) iferr_return ; stream.Write(logDataMem) iferr_return ; stream.Close() iferr_return ;
// This example loads a file from the web and saves it to the local file system.
// check if the given URL references a file on the web const maxon::UrlScheme scheme = webFile.GetScheme(); const maxon::Bool isHTTP = scheme == maxon::URLSCHEME_HTTP ; const maxon::Bool isHTTPS = scheme == maxon::URLSCHEME_HTTPS ; if (isHTTP || isHTTPS) { // read data
// input stream const maxon::InputStreamRef inputStream = webFile.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 ;
// save data to file
// prepare file name const maxon::Url localFile = (targetFolder + webFile.GetName()) iferr_return ; // output stream const maxon::OutputStreamRef outputStream = localFile.OpenOutputStream() iferr_return ; // write to file outputStream.Write(data) iferr_return ; outputStream.Close() iferr_return ; }
// This example reads the content of a stream using ReadEOS().
// open stream const maxon::InputStreamRef inputStream = webFile.OpenInputStream() iferr_return ;
// prepare memory maxon::BaseArray<maxon::Char> data; data. Resize (predictedSize) iferr_return ;
// read until end of stream const maxon::Int streamSize = inputStream.ReadEOS(data) iferr_return ;
// resize if (streamSize < predictedSize) { data. Resize (streamSize) iferr_return ; }
maxon::URLFLAGS can be used to define maxon::Url attributes.
// Prepares the data that will be post maxon::String postData = "foo=bar&bin=go" _s; theServer.Set(maxon::URLFLAGS::HTTP_POSTMETHOD, maxon::HTTPMETHOD::POST ) iferr_return ; theServer.Set(maxon::URLFLAGS::HTTP_POSTDATA, maxon::CString (postData, maxon::StringEncodings::Utf8())) iferr_return ; maxon::BaseArray<maxon::Char> memReq;
// Retrieves the answer and read it to memory iferr ( maxon::FileUtilities::ReadFileToMemory (theServer, memReq)) DiagnosticOutput ( "@" , err);
// Prints the answer from server ApplicationOutput ( "answer @" , memReq);
// Prints the answer as a string maxon::String result(memReq); ApplicationOutput ( "result @" , result);
Miscellaneous functions are:
