Method downloadFromSource

Modules/Scripted/SampleData/SampleData.py:850–981

Given an instance of SampleDataSource, downloads the associated data and load them into Slicer if it applies. The function always returns a list. Based on the fileType(s), nodeName(s) and loadFile(s) associated with the source, different values may be appended to th

(self, source, maximumAttemptsCount=3, forceDownload=False)

        return filePaths

    def downloadFromSource(self, source, maximumAttemptsCount=3, forceDownload=False):
        """Given an instance of SampleDataSource, downloads the associated data and
        load them into Slicer if it applies.

        The function always returns a list.

        Based on the fileType(s), nodeName(s) and loadFile(s) associated with
        the source, different values may be appended to the returned list:

          - if nodeName is specified, appends loaded nodes but if ``loadFile`` is False appends downloaded filepath
          - if fileType is ``SceneFile``, appends downloaded filepath
          - if fileType is ``ZipFile``, appends directory of extracted archive but if ``loadFile`` is False appends downloaded filepath

        If no ``nodeNames`` and no ``fileTypes`` are specified or if ``loadFiles`` are all False,
        returns the list of all downloaded filepaths.

        If ``forceDownload`` is True then existing files are downloaded again (if no hash is provided).
        """

        # Input may contain urls without associated node names, which correspond to additional data files
        # (e.g., .raw file for a .nhdr header file). Therefore we collect nodes and file paths separately
        # and we only return file paths if no node names have been provided.
        resultNodes = []
        resultFilePaths = []

        # If some node names are defined and some are left empty then we assume that it is intentional
        # (e.g., you only want to load the image.nhdr file and not the image.raw file).
        # In this case default node names are not generated.
        generateDefaultNodeNames = all(n is None for n in source.nodeNames)

        for uri, fileName, nodeName, checksum, loadFile, loadFileType in zip(
            source.uris, source.fileNames, source.nodeNames, source.checksums, source.loadFiles, source.loadFileTypes, strict=False):

            if nodeName is None or fileName is None:
                # Determine file basename and extension from URL or path
                import urllib
                import uuid
                if fileName is not None:
                    basename, ext = os.path.splitext(os.path.basename(fileName))
                else:
                    p = urllib.parse.urlparse(uri)
                    basename, ext = os.path.splitext(os.path.basename(p.path))

                # Generate default node name (we only need this if we want to load the file into the scene and no node name is provided)
                if (nodeName is None) and (loadFile is not False) and generateDefaultNodeNames:
                    nodeName = basename

                # Generate default file name (we always need this, even for just downloading)
                if fileName is None:
                    # Generate a unique filename to avoid overwriting existing file with the same name
                    fileName = f"{nodeName if nodeName else basename}-{uuid.uuid4().hex}{ext}"

            current_source = SampleDataSource(
                uris=uri,
                fileNames=fileName,
                nodeNames=nodeName,
                checksums=checksum,
                loadFiles=loadFile,