class ResRec(rscdef.IVOMetaMixin, NonServiceResource):
    """A resource for pure registration purposes.

	A Resource does nothing; it is for registration of Authorities,
	Organizations, Instruments, or whatever.  Thus, they consist
	of metadata only (resources that do something are services; they
	carry their own metadata and care for their registration themselves.).

	All resources must either have an id (which is used in the construction of
	their IVOID), or you must give an identifier meta item.
	
	You must further set the following meta items:

	   - resType specifying the kind of resource record.  You should not
	     use this element to build resource records for services or tables
	     (use the normal elements, even if the actual resrouces are external
	     to DaCHS).  resType can be registry, organization, authority, 
	     deleted, or anything else for which registry.builders has a
	     handling class.
	   - title
	   - subject(s)
	   - description
	   - referenceURL
	   - creationDate
	
	Additional meta keys (e.g., accessURL for a registry) may be required 
	depending on resType.  See the registry session in the operator's guide.
	"""
    name_ = "resRec"
    _rd = rscdef.RDAttribute()
class DirectGrammar(base.Structure, base.RestrictionMixin):
    """A user-defined external grammar.

	See the separate document on user-defined code on more on direct grammars.

	Also note the program gavomkboost that can help you generate core for
	the C boosters used by direct grammars.
	"""
    name_ = "directGrammar"

    _cbooster = rscdef.ResdirRelativeAttribute(
        "cBooster",
        default=base.Undefined,
        description="resdir-relative path to the booster C source.",
        copyable=True)

    _gzippedInput = base.BooleanAttribute(
        "gzippedInput",
        default=False,
        description="Pipe gzip before booster? (will not work for FITS)",
        copyable=True)

    _autoNull = base.UnicodeAttribute(
        "autoNull",
        default=None,
        description="Use this string as general NULL value (when reading"
        " from plain text).",
        copyable=True)

    _ignoreBadRecords = base.BooleanAttribute(
        "ignoreBadRecords",
        default=False,
        description="Let booster ignore invalid records?",
        copyable=True)

    _recordSize = base.IntAttribute(
        "recordSize",
        default=4000,
        description="For bin boosters, read this many bytes to make"
        " up a record; for line-based boosters, this is the maximum"
        " length of an input line.",
        copyable=True)

    _preFilter = base.UnicodeAttribute(
        "preFilter",
        default=None,
        description="Pipe input through this program before handing it to"
        " the booster; this string is shell-expanded (will not work for FITS).",
        copyable=True)

    _customFlags = base.UnicodeAttribute(
        "customFlags",
        default="",
        description="Pass these flags to the C compiler when building the"
        " booster.",
        copyable=True)

    _type = base.EnumeratedUnicodeAttribute(
        "type",
        default="col",
        validValues=["col", "bin", "fits", "split"],
        description="Make code for a booster parsing by column indices (col),"
        " by splitting along separators (split), by reading fixed-length"
        " binary records (bin), for from FITS binary tables (fits).",
        copyable=True)

    _splitChar = base.UnicodeAttribute(
        "splitChar",
        default="|",
        description="For split boosters, use this as the separator.",
        copyable=True)

    _ext = base.IntAttribute(
        "extension",
        default=1,
        description=
        "For FITS table boosters, get the table from this extension.",
        copyable=True)

    _mapKeys = base.StructAttribute(
        "mapKeys",
        childFactory=common.MapKeys,
        default=None,
        copyable=True,
        description="For a FITS booster, map DB table column names"
        " to FITS column names (e.g., if the FITS table name flx is to"
        " end up in the DB column flux, say flux:flx).")

    _rd = rscdef.RDAttribute()

    isDispatching = False

    def validate(self):
        self._validateNext(DirectGrammar)
        if self.type == 'bin':
            if not self.recordSize:
                raise base.StructureError(
                    "DirectGrammars reading from binary need"
                    " a recordSize attribute")
        if self.mapKeys is not None:
            if self.type != "fits":
                raise base.StructureError("mapKeys is only allowed for FITS"
                                          " boosters.")

    def onElementComplete(self):
        if self.type == "fits":
            if self.mapKeys:
                self.keyMap = self.mapKeys.maps
            else:
                self.keyMap = {}

    def getBooster(self):
        return CBooster(self.cBooster,
                        self.parent,
                        gzippedInput=self.gzippedInput,
                        preFilter=self.preFilter,
                        autoNull=self.autoNull,
                        ignoreBadRecords=self.ignoreBadRecords,
                        customFlags=self.customFlags)

    def parse(self, sourceToken, targetData=None):
        booster = self.getBooster()
        makes = self.parent.makes
        if len(makes) != 1:
            raise base.StructureError(
                "Directgrammar only works for data having"
                " exactly one table, but data '%s' has %d" %
                (self.parent.id, len(makes)))

        def copyIn(data):
            data.tables.values()[0].copyIn(booster.getOutput(sourceToken))
            if booster.getStatus():
                raise base.SourceParseError("Booster returned error signature",
                                            source=sourceToken)

        return copyIn
class Publication(base.Structure, base.ComputedMetaMixin):
    """A specification of how a service should be published.

	This contains most of the metadata for what is an interface in
	registry speak.
	"""
    name_ = "publish"

    _rd = rscdef.RDAttribute()
    _render = base.UnicodeAttribute(
        "render",
        default=base.Undefined,
        description="The renderer the publication will point at.",
        copyable=True)
    _sets = base.StringSetAttribute(
        "sets",
        description="Comma-separated list of sets this service will be"
        " published in.  Predefined are: local=publish on front page,"
        " ivo_managed=register with the VO registry.  If you leave it"
        " empty, 'local' publication is assumed.",
        copyable="True")
    _service = base.ReferenceAttribute(
        "service",
        default=base.NotGiven,
        description="Reference for a service actually implementing the"
        " capability corresponding to this publication.  This is"
        " mainly when there is a vs:WebBrowser service accompanying a VO"
        " protocol service, and this other service should be published"
        " in the same resource record.  See also the operator's guide.",
        copyable="True")
    _auxiliary = base.BooleanAttribute(
        "auxiliary",
        default=False,
        description="Auxiliary publications are for capabilities"
        " not intended to be picked up for all-VO queries, typically"
        " because they are already registered with other services."
        " This is mostly used internally; you probably have no reason"
        " to touch it.")

    def completeElement(self, ctx):
        if self.render is base.Undefined:
            self.render = "form"
        if not self.sets:
            self.sets.add("local")
        if self.service is base.NotGiven:
            self.service = self.parent
        self.setMetaParent(self.service)
        self._completeElementNext(Publication, ctx)

    def validate(self):
        self._validateNext(Publication)
        try:
            renderers.getRenderer(self.render)
        except KeyError:
            raise base.StructureError("Unknown renderer: %s" % self.render)

    def _meta_accessURL(self):
        return self.service.getURL(self.render)

    def _meta_urlUse(self):
        return renderers.getRenderer(self.render).urlUse

    def _meta_requestMethod(self):
        return renderers.getRenderer(self.render).preferredMethod

    def _meta_resultType(self):
        return renderers.getRenderer(self.render).resultType
class Service(base.Structure, base.ComputedMetaMixin, base.StandardMacroMixin,
              rscdef.IVOMetaMixin):
    """A service definition.

	A service is a combination of a core and one or more renderers.  They
	can be published, and they carry the metadata published into the VO.

	You can set the defaultSort property on the service to a name of an
	output column to preselect a sort order.  Note again that this will
	slow down responses for all but the smallest tables unless there is
	an index on the corresponding column.

	Properties evaluated:

	* defaultSort -- a key to sort on by default with the form renderer.  
	  This differs from the dbCore's sortKey in that this does not suppress the
	  widget itself, it just sets a default for its value.  Don't use this unless
	  you have to; the combination of sort and limit can have disastrous effects
	  on the run time of queries.
	* votableRespectsOutputTable -- usually, VOTable output puts in
	  all columns from the underlying database table with low enough
	  verbLevel (essentially).  When this property is "True" (case-sensitive),
		that's not done and only the service's output table is evaluated.
		[Note that column selection is such a mess it needs to be fixed
		before version 1.0 anyway]
	"""
    name_ = "service"

    _core = CoreAttribute()
    _templates = base.DictAttribute(
        "templates",
        description="Custom"
        ' nevow templates for this service; use key "form" to replace the Form'
        " renderer's standard template.  Start the path with two slashes to"
        " access system templates.",
        itemAttD=rscdef.ResdirRelativeAttribute(
            "template",
            description="resdir-relative path to a nevow template"
            " used for the function given in key."),
        copyable=True)
    _publications = base.StructListAttribute(
        "publications",
        childFactory=Publication,
        description="Sets and renderers this service"
        " is published with.")
    _limitTo = base.UnicodeAttribute(
        "limitTo",
        default=None,
        description="Limit access to the group given; the empty default disables"
        " access control.",
        copyable="True")
    _customPage = rscdef.ResdirRelativeAttribute(
        "customPage",
        default=None,
        description="resdir-relative path to custom page code.  It is used"
        " by the 'custom' renderer",
        copyable="True")
    _allowedRenderers = base.StringSetAttribute(
        "allowed",
        description="Names of renderers allowed on this service; leave emtpy"
        " to allow the form renderer only.",
        copyable=True)
    _customRF = base.StructListAttribute(
        "customRFs",
        description="Custom render functions for use in custom templates.",
        childFactory=CustomRF,
        copyable=True)
    _customDF = base.StructListAttribute(
        "customDFs",
        description="Custom data functions for use in custom templates.",
        childFactory=CustomDF,
        copyable=True)
    _inputData = base.StructAttribute(
        "inputDD",
        default=base.NotGiven,
        childFactory=inputdef.InputDescriptor,
        description="A data descriptor"
        " for obtaining the core's input, usually based on a contextGrammar."
        "  For many cores (e.g., DBCores), you do not want to give this"
        " but rather want to let service figure this out from the core.",
        copyable=True)
    _outputTable = base.StructAttribute(
        "outputTable",
        default=base.NotGiven,
        childFactory=outputdef.OutputTableDef,
        copyable=True,
        description="The output fields of this service.")
    _serviceKeys = base.StructListAttribute(
        "serviceKeys",
        childFactory=inputdef.InputKey,
        description="Input widgets for"
        " processing by the service, e.g. output sets.",
        copyable=True)
    _defaultRenderer = base.UnicodeAttribute(
        "defaultRenderer",
        default=None,
        description="A name of a renderer used when"
        " none is provided in the URL (lets you have shorter URLs).")
    _rd = rscdef.RDAttribute()
    _props = base.PropertyAttribute()
    _original = base.OriginalAttribute()

    metaModel = ("title(1), creationDate(1), description(1),"
                 "subject, referenceURL(1), shortName(!)")

    # formats that should query the same fields as HTML (the others behave
    # like VOTables and offer a "verbosity" widget in forms).
    htmlLikeFormats = ["HTML", "tar"]

    ####################### Housekeeping methods

    def __repr__(self):
        return "<Service at %x>" % id(self)

    def completeElement(self, ctx):
        self._completeElementNext(Service, ctx)
        if not self.allowed:
            self.allowed.add("form")

        if self.core is base.Undefined:
            # undefined cores are only allowed with custom pages
            # (Deprecated)
            if self.customPage:
                self.core = core.getCore("nullCore")(
                    self.rd).finishElement(None)
                base.ui.notifyWarning(
                    "Custom page service %s without nullCore."
                    "  This is deprecated, please fix" % self.id)
            else:
                raise base.StructureError(
                    "Services must have cores (add <nullCore/>"
                    " if you really do not want a core, e.g., with fixed renderers)."
                )

        # if there's only one renderer on this service, make it the default
        if self.defaultRenderer is None and len(self.allowed) == 1:
            self.defaultRenderer = list(self.allowed)[0]
        # empty output tables are filled from the core
        if self.outputTable is base.NotGiven:
            self.outputTable = self.core.outputTable

        # cache all kinds of things expensive to create and parse
        self._coresCache = {}
        self._inputDDCache = {}
        self._loadedTemplates = {}

        # Schedule the capabilities to be added when the parse is
        # done (i.e., the RD is complete)
        ctx.addExitFunc(lambda rd, ctx: self._addAutomaticCapabilities())

    def onElementComplete(self):
        self._onElementCompleteNext(Service)

        # Index custom render/data functions
        self.nevowRenderers = {}
        for customRF in self.customRFs:
            self.nevowRenderers[customRF.name] = customRF.func
        self.nevowDataFunctions = {}
        for customDF in self.customDFs:
            self.nevowDataFunctions[customDF.name] = customDF.func

        self._compileCustomPage()

        self._computeResourceType()

    def _compileCustomPage(self):
        if self.customPage:
            try:
                modNs, moddesc = utils.loadPythonModule(self.customPage)
                modNs.RD = self.rd
                getattr(modNs, "initModule", lambda: None)()
                page = modNs.MainPage
            except ImportError:
                raise base.ui.logOldExc(
                    base.LiteralParseError(
                        "customPage",
                        self.customPage,
                        hint=
                        "This means that an exception was raised while DaCHS"
                        " tried to import the renderer module.  If DaCHS ran"
                        " with --debug, the original traceback is available"
                        " in the logs."))
            self.customPageCode = page, (os.path.basename(
                self.customPage), ) + moddesc

    def getTemplate(self, key):
        """returns the nevow template for the function key on this service.
		"""
        if key not in self._loadedTemplates:
            from nevow import loaders
            tp = self.templates[key]
            if tp.startswith("//"):
                self._loadedTemplates[key] = common.loadSystemTemplate(tp[2:])
            else:
                self._loadedTemplates[key] = loaders.xmlfile(
                    os.path.join(self.rd.resdir, tp))
        return self._loadedTemplates[key]

    def getUWS(self):
        """returns a user UWS instance for this service.

		This is a service for the UWSAsyncRenderer.
		"""
        if not hasattr(self, "uws"):
            from gavo.protocols import useruws
            self.uws = useruws.makeUWSForService(self)
        return self.uws

    ################### Registry and related methods.

    @property
    def isVOPublished(self, renderer=None):
        """is true if there is any ivo_managed publication on this
		service.

		If renderer is non-None, only publications with this renderer name
		count.
		"""
        for pub in self.publications:
            if "ivo_managed" in pub.sets:
                if renderer:
                    if pub.render == renderer:
                        return True
                else:
                    return True
        return False

    def _computeResourceType(self):
        """sets the resType attribute.

		Services are resources, and the registry code wants to know what kind.
		This method ventures a guess.  You can override this decision by setting
		the resType meta item.
		"""
        if (self.outputTable.columns or self.outputTable.verbLevel
                or "tap" in self.allowed):
            self.resType = "catalogService"
        else:  # no output table defined, we're a plain service
            self.resType = "nonTabularService"

    def _addAutomaticCapabilities(self):
        """adds some publications that are automatic for certain types
		of services.

		For services with ivo_managed publications and with useful cores
		(this keeps out doc-like publications, which shouldn't have VOSI
		resources), artificial VOSI publications are added.

		If there is _example meta, an examples publication is added.

		If this service exposes a table (i.e., a DbCore with a queriedTable)
		and that table is adql-readable, also add an auxiliary TAP publication
		if going to the VO.

		This is being run as an exit function from the parse context as
		we want the RD to be complete at this point (e.g., _examples
		meta might come from it).  This also lets us liberally resolve
		references anywhere.
		"""
        if not self.isVOPublished:
            return
        vosiSet = set(["ivo_managed"])

        # All actual services get VOSI caps
        if not isinstance(self.core, core.getCore("nullCore")):
            self._publications.feedObject(
                self,
                base.makeStruct(Publication,
                                render="availability",
                                sets=vosiSet,
                                parent_=self))
            self._publications.feedObject(
                self,
                base.makeStruct(Publication,
                                render="capabilities",
                                sets=vosiSet,
                                parent_=self))
            self._publications.feedObject(
                self,
                base.makeStruct(Publication,
                                render="tableMetadata",
                                sets=vosiSet,
                                parent_=self))

        # things querying tables get a TAP relationship if
        # their table is adql-queriable
        if isinstance(self.core, core.getCore("dbCore")):
            if self.core.queriedTable.adql:
                tapService = base.resolveCrossId("//tap#run")
                self._publications.feedObject(
                    self,
                    base.makeStruct(Publication,
                                    render="tap",
                                    sets=vosiSet,
                                    auxiliary=True,
                                    service=tapService,
                                    parent_=self))
                # and they need a servedBy, too.
                # According to the "discovering dependent" note, we don't
                # do the reverse relationship lest the TAP service
                # gets too related...
                self.addMeta("servedBy",
                             base.getMetaText(tapService, "title"),
                             ivoId=base.getMetaText(tapService, "identifier"))

        # things with examples meta get an examples capability
        try:
            self.getMeta("_example", raiseOnFail=True)
            self._publications.feedObject(
                self,
                base.makeStruct(Publication,
                                render="examples",
                                sets=utils.AllEncompassingSet(),
                                parent_=self))
        except base.NoMetaKey:
            pass

    def getPublicationsForSet(self, names):
        """returns publications for set names in names.

		names must be a set.  
		"""
        additionals = []
        # for ivo_managed, also return a datalink endpoints if they're
        # there; the specs imply that might be useful some day.
        if self.getProperty("datalink", None):
            dlSvc = self.rd.getById(self.getProperty("datalink"))
            if "dlget" in dlSvc.allowed:
                additionals.append(
                    base.makeStruct(Publication,
                                    render="dlget",
                                    sets="ivo_managed",
                                    service=dlSvc))

            if "dlasync" in dlSvc.allowed:
                additionals.append(
                    base.makeStruct(Publication,
                                    render="dlasync",
                                    sets="ivo_managed",
                                    service=dlSvc))

            if "dlmeta" in dlSvc.allowed:
                additionals.append(
                    base.makeStruct(Publication,
                                    render="dlmeta",
                                    sets="ivo_managed",
                                    service=dlSvc))

        return [pub
                for pub in self.publications if pub.sets & names] + additionals

    def getURL(self, rendName, absolute=True, **kwargs):
        """returns the full canonical access URL of this service together 
		with renderer.

		rendName is the name of the intended renderer in the registry
		of renderers.

		With absolute, a fully qualified URL is being returned.

		Further keyword arguments are translated into URL parameters in the
		query part.
		"""
        basePath = "%s%s/%s" % (base.getConfig(
            "web", "nevowRoot"), self.rd.sourceId, self.id)
        if absolute:
            basePath = base.getConfig("web", "serverURL") + basePath
        res = renderers.getRenderer(rendName).makeAccessURL(basePath)

        if kwargs:
            res = res + "?" + urllib.urlencode(kwargs)
        return res

    # used by getBrowserURL; keep external higher than form as long as
    # we have mess like Potsdam CdC.
    _browserScores = {
        "form": 10,
        "external": 12,
        "fixed": 15,
        "custom": 3,
        "img.jpeg": 2,
        "static": 1
    }

    def getBrowserURL(self, fq=True):
        """returns a published URL that's suitable for a web browser or None if
		no such URL can be guessed.

		If you pass fq=False, you will get a path rather than a URL.
		"""
        # There can be multiple candidates for browser URLs (like when a service
        # has both form, static, and external renderers).  If so, we select
        # by plain scores.
        browseables = []
        for rendName in self.allowed:
            if self.isBrowseableWith(rendName):
                browseables.append((self._browserScores.get(rendName,
                                                            -1), rendName))
        if browseables:
            return self.getURL(max(browseables)[1], absolute=fq)
        else:
            return None

    def isBrowseableWith(self, rendName):
        """returns true if rendering this service through rendName results 
		in something pretty in a web browser.
		"""
        try:
            return bool(renderers.getRenderer(rendName).isBrowseable(self))
        except base.NotFoundError:  # renderer name not known
            return False

    def getTableSet(self):
        """returns a list of table definitions that have something to do with
		this service.

		This is for VOSI-type queries.  Usually, that's just the core's
		queried table or an output table, except when there is a TAP renderer on
		the service.

		All this is a bit heuristic; but then again, there's no rigorous 
		definition for what's to be in a tables endpoint either.
		"""
        tables = []

        # output our own outputTable if it sounds reasonable; if so,
        # add the core's queried table, too, if it has one.
        if self.outputTable and self.outputTable.columns:
            tables.append(self.outputTable)
            tables.append(getattr(self.core, "queriedTable", None))

        else:
            # if our outputTable is no good, just use the one of the core
            qt = getattr(self.core, "queriedTable", None)
            if qt is None:
                qt = getattr(self.core, "outputTable", None)
            if qt is not None:
                tables.append(qt)

        # XXX TODO: This stinks big time.  It's because we got TAP factorization
        # wrong.  Sync and async should be renderers, and there should
        # be a core that then could say this kind of thing.  That's not
        # yet the case, so:
        if "tap" in self.allowed:
            # tap never has "native" tables, so start afresh
            tables = []

            mth = base.caches.getMTH(None)
            for tableName in mth.getTAPTables():
                try:
                    tables.append(mth.getTableDefForTable(tableName))
                except:
                    base.ui.notifyError(
                        "Failure trying to retrieve table definition"
                        " for table %s.  Please fix the corresponding RD." %
                        tableName)

        return [t for t in tables if t is not None and t.rd is not None]

    def declareServes(self, data):
        """adds meta to self and data indicating that data is served by
		service.

		This is used by table/@adql and the publish element on data.
		"""
        if data.registration:
            self.addMeta("serviceFor",
                         base.getMetaText(data, "title", default="Anonymous"),
                         ivoId=base.getMetaText(data, "identifier"))
            data.addMeta("servedBy",
                         base.getMetaText(self, "title"),
                         ivoId=base.getMetaText(self, "identifier"))

            # Since this is always initiated by the data, the dependency
            # must show up in its RD to be properly added on publication
            # and to be removed when the data is removed.
            data.rd.addDependency(self.rd, data.rd)

    ########################## Output field selection (ouch!)

    def _getVOTableOutputFields(self, queryMeta):
        """returns a list of OutputFields suitable for a VOTable response 
		described by queryMeta.

		This is what's given for HTML when the columns verbLevel is low
		enough and there's no displayHint of noxml present. 
		
		In addition, more columns are added from outputTable's parent (which 
		usually will be the database table itself) if their verbLevel is low
		enough.  this may be suppressed by setting the
		votableRespectsOutputTable property to "True".
		"""
        verbLevel = queryMeta.get("verbosity", 20)
        fields = [
            f for f in self.getHTMLOutputFields(queryMeta) if
            f.verbLevel <= verbLevel and f.displayHint.get("noxml") != "true"
        ]

        if (verbLevel != "HTML" and self.getProperty(
                "votableRespectsOutputTable", None) != "True"):
            htmlNames = set(f.name for f in fields)

            for field in self.outputTable.parentTable:
                if field.name in htmlNames:
                    continue
                if (field.displayHint.get("type") == "suppress"
                        or field.displayHint.get("noxml") == "true"):
                    continue
                if field.verbLevel <= verbLevel:
                    fields.append(field)

        return rscdef.ColumnList(fields)

    _allSet = set(["ALL"])

    def getHTMLOutputFields(self,
                            queryMeta,
                            ignoreAdditionals=False,
                            raiseOnUnknown=True):
        """returns a list of OutputFields suitable for an HTML response described
		by queryMeta.

		raiseOnUnknown is used by customwidgets to avoid exceptions because of
		bad additional fields during form construction (when they aren't
		properly caught).
		"""
        requireSet = queryMeta["columnSet"]
        res = rscdef.ColumnList()

        # add "normal" output fields
        if requireSet:
            res.extend([
                f for f in self.outputTable
                if f.sets == self._allSet or requireSet & f.sets
            ])
        else:
            res.extend([
                f for f in self.outputTable
                if f.displayHint.get("type") != "suppress"
            ])

        # add user-selected fields
        if not ignoreAdditionals and queryMeta["additionalFields"]:
            cofs = self.core.outputTable.columns
            try:
                for fieldName in queryMeta["additionalFields"]:
                    col = cofs.getColumnByName(fieldName)
                    if isinstance(col, outputdef.OutputField):
                        res.append(col)
                    else:
                        res.append(outputdef.OutputField.fromColumn(col))
            except base.NotFoundError, msg:
                if raiseOnUnknown:
                    raise base.ValidationError(
                        "The additional field %s you requested"
                        " does not exist" % repr(msg.lookedFor),
                        colName="_OUTPUT")
        return res
示例#5
0
class Core(base.Structure):
    """A definition of the "active" part of a service.

	Cores receive their input in tables the structure of which is
	defined by their inputTable attribute.

	The abstract core element will never occur in resource descriptors.  See 
	`Cores Available`_ for concrete cores.  Use the names of the concrete
	cores in RDs.

	You can specify an input table in an inputTableXML and an output table
	in an outputTableXML class attribute.
	"""
    name_ = "core"

    inputTableXML = None
    outputTableXML = None

    # the cached prototype of the output table, filled in by
    # _OutputTableFactory
    _ot_prototype = None

    _rd = rscdef.RDAttribute()
    _inputTable = base.StructAttribute(
        "inputTable",
        default=base.NotGiven,
        childFactory=inputdef.InputTable,
        description="Description of the input data",
        copyable=True)

    _outputTable = base.StructAttribute(
        "outputTable",
        default=base.NotGiven,
        childFactory=_OutputTableFactory(),
        description="Table describing what fields are available from this core",
        copyable=True)

    _original = base.OriginalAttribute()

    _properties = base.PropertyAttribute()

    def __init__(self, parent, **kwargs):
        if self.inputTableXML is not None:
            if "inputTable" not in kwargs:
                kwargs["inputTable"] = base.parseFromString(
                    inputdef.InputTable, self.inputTableXML)

        base.Structure.__init__(self, parent, **kwargs)

    def __repr__(self):
        return "<%s at %s>" % (self.__class__.__name__, id(self))

    def __str__(self):
        return repr(self)

    def completeElement(self, ctx):
        self._completeElementNext(Core, ctx)
        if self.inputTable is base.NotGiven:
            self.inputTable = base.makeStruct(inputdef.InputTable)
        if self.outputTable is base.NotGiven:
            self.outputTable = self._outputTable.childFactory(self)

    def adaptForRenderer(self, renderer):
        """returns a core object tailored for renderer.
		"""
        newIT = self.inputTable.adaptForRenderer(renderer)
        if newIT is self.inputTable:
            return self
        else:
            return self.change(inputTable=newIT)

    def run(self, service, inputData, queryMeta):
        raise NotImplementedError("%s cores are missing the run method" %
                                  self.__class__.__name__)

    def makeUserDoc(self):
        return ("Polymorphous core element.  May contain any of the cores"
                " mentioned in `Cores Available`_ .")