# Source code for stetl.filters.xsltfilter

    #!/usr/bin/env python
    #
    # Transformation of an etree doc with XSLT.
    #
    # Author:Just van den Broecke

    from stetl.component import Config
    from stetl.util import Util, etree
    from stetl.filter import Filter
    from stetl.packet import FORMAT

    log = Util.get_log("xsltfilter")

    class XsltFilter(Filter):
        """
        Invokes XSLT processor (via lxml) for given XSLT script on an etree doc.

        consumes=FORMAT.etree_doc, produces=FORMAT.etree_doc
        """

        @Config(ptype=str, required=True)
        def script(self):
            """
            Path to XSLT script file.
            """
            pass

        # Constructor
        def __init__(self, configdict, section):
            Filter.__init__(self, configdict, section, consumes=FORMAT.etree_doc, produces=FORMAT.etree_doc)

            self.xslt_file = open(self.script, 'r')

            # Parse XSLT file only once
            self.xslt_doc = etree.parse(self.xslt_file)
            self.xslt_obj = etree.XSLT(self.xslt_doc)
            self.xslt_file.close()

        def invoke(self, packet):
            if packet.data is None:
                return packet
            return self.transform(packet)

        def transform(self, packet):
            packet.data = self.xslt_obj(packet.data)
            log.info("XSLT Transform OK")
            return packet