""" $RCSfile: XPathMethod.py,v $ ZopeXMLMethods provides methods to apply to Zope objects for XML/XSLT processing. XPathMethod applies XPath expressions to XML documents. XPathMethod automatically filters an XML document via XPath, where the XML document is obtained from another Zope object (the 'source' object) via acquisition. Author: Craeg Strong Release: 1.0 $Id: XPathMethod.py,v 1.2 2003/06/16 05:47:53 arielpartners Exp $ """ __cvstag__ = '$Name: $'[6:-2] __date__ = '$Date: 2003/06/16 05:47:53 $'[6:-2] __version__ = '$Revision: 1.2 $'[10:-2] # peer classes/modules from interfaces import IXPathMethod from processors.interfaces import IXPathProcessor from processors.ProcessorRegistry import ProcessorRegistry from GeneratorRegistry import GeneratorRegistry # our base class from XMLMethod import XMLMethod, getPublishedResult, \ PERM_VIEW, PERM_EDIT, PERM_FTP, PERM_CONTENT, PERM_MANAGE # Zope builtins import Globals from Globals import MessageDialog from AccessControl import ClassSecurityInfo from Products.PageTemplates.PageTemplateFile import PageTemplateFile from zope.interface import implements ################################################################ # Defaults ################################################################ xpathExpressionPropertyName = 'XPathexpression' ################################################################ # Module Scoped Convenience Methods ################################################################ def addInstance(folder, id, title='', description='', selected_processor='', xpathExpression='', content_type='text/xml', behave_like='', debugLevel=0): """ This is a convenience factory method for creating an instance of XPathMethod. It returns the object created, and may therefore be more convenient than the addXPathMethod() method it calls. It is used by the unit testing programs. """ folder.manage_addProduct['ZopeXMLMethods'].addXPathMethod( id, title, description, selected_processor, xpathExpression, content_type, behave_like, debugLevel) return folder[id] ################################################################ # Contructors ################################################################ manage_addXPathMethodForm = PageTemplateFile('www/createXPath.pt', globals()) def manage_addXPathMethod(self, id, title='', description='', selected_processor='', xpathExpression='', content_type='text/xml', behave_like='', debugLevel=0, REQUEST=None, RESPONSE=None): """ Factory method to create an instance of XPathMethod, called from a GUI in the Zope Management Interface. It calls addXPathMethod to actually do the work. """ try: self.addXPathMethod(id, title, description, selected_processor, xpathExpression, content_type, behave_like, debugLevel) message = 'Successfully created ' + id + ' XPathMethod object.' if REQUEST is None: return try: url = self.DestinationURL() except: url = REQUEST['URL1'] REQUEST.RESPONSE.redirect(url + "/manage_main") except Exception, e: message = str(e) message.replace('\n','
') return MessageDialog(title = 'Error', message = message, action = 'manage_main') def addXPathMethod(self, id, title='', description='', selected_processor='', xpathExpression='', content_type='text/xml', behave_like='', debugLevel=0): """ Factory method to actually create an instance of XPathMethod and return it. You should call this method directly if you are creating an instance of XPathMethod programatically. """ if not id or not xpathExpression: raise Exception('Required fields must not be blank') # Insert test for invalid XPath here if 0: message = "Invalid XPath expression %s" % (xpathExpression) raise Exception(message) self._setObject(id, XPathMethod(id, title, description, selected_processor, xpathExpression, content_type, behave_like, debugLevel)) self._getOb(id).reindex_object() def availableProcessors(self): """ Return names of currently available XPath processor libraries """ return ProcessorRegistry.names(IXPathProcessor) ################################################################ # Main class ################################################################ class XPathMethod(XMLMethod): """ Automatically filters an XML document via XPath, where the XML document is obtained from another Zope object (the 'source' object) via acquisition. """ meta_type = 'XPath Method' implements(IXPathMethod) _security = ClassSecurityInfo() _properties = XMLMethod._properties + ( {'id':'xpathExpression', 'type':'string', 'mode': 'w' }, ) # manage_options inherited from XMLMethod def __init__(self, id, title, description, selected_processor, xpathExpression, content_type="text/html", behave_like='', debugLevel=0): XMLMethod.__init__(self, id, title, description, selected_processor, content_type, behave_like, debugLevel) # string attributes self.xpathExpression = xpathExpression # if selected_processor is blank, get the default if not self.selected_processor: self.selected_processor = ProcessorRegistry.defaultName(IXPathProcessor) ################################################################ # Methods implementing the IXPathMethod interface below ################################################################ _security.declarePublic('availableProcessors') def availableProcessors(self): """ Return names of currently available XPath processor libraries """ return ProcessorRegistry.names(IXPathProcessor) _security.declarePublic('processor') def processor(self): """ Obtain the object encapsulating the selected XPath processor. """ return ProcessorRegistry.item(IXPathProcessor, self.selected_processor) _security.declareProtected(PERM_VIEW, 'evaluateString') def evaluateString(self, REQUEST): """ Generate result of applying XPath against source XML and return it as a string """ processor = self.processor() xmlObject = self.getXmlSourceObject() xmlContents = getPublishedResult("XML source", xmlObject, REQUEST) xmlURL = xmlObject.absolute_url() processor.setDebugLevel(self.debugLevel) # Q: why don't we precompile the expression? # A: because we don't want to pickle a processor-specific type # CKS 6/13/2003 expr = processor.compile(self.xpathExpression) return expr.evaluateString(xmlContents, xmlURL, prettyPrint = 1) _security.declareProtected(PERM_VIEW, 'evaluateDOM') def evaluateDOM(self, REQUEST): """ Generate result of applying XPath against source XML and return it as a list of DOM nodes """ processor = self.processor() xmlObject = self.getXmlSourceObject() xmlContents = getPublishedResult("XML source", xmlObject, REQUEST) xmlURL = xmlObject.absolute_url() processor.setDebugLevel(self.debugLevel) # Q: why don't we precompile the expression? # A: because we don't want to pickle a processor-specific type # CKS 6/13/2003 expr = processor.compile(self.xpathExpression) return expr.evaluateDOM(xmlContents, xmlURL) ################################################################ # Standard Zope stuff ################################################################ _security.declareProtected(PERM_VIEW, '__call__') def __call__(self, client=None, REQUEST=None, RESPONSE=None): """ Render self by processing its content with the named XPath """ rawResult = self.evaluateString(REQUEST) if self.behave_like == "": behave_like = self.getXmlSourceObject().meta_type else: behave_like = self.behave_like gen = GeneratorRegistry.getGenerator(behave_like) if gen is None: gen = GeneratorRegistry.getDefaultGenerator() # explicitly set the Content-Type here because calling the XML # source object or the XPath method might have # changed it and the call of gen.getResult() below doesn't # guarantee that it will be changed back. if RESPONSE is not None: RESPONSE.setHeader("Content-Type", self.content_type) obj = gen.createObject(self.id, self.title, rawResult, content_type = self.content_type) if client is None: client = self return gen.getResult(obj, client, REQUEST, RESPONSE) ################################################################ # Support for Schema Migration ################################################################ def repair(self): """ Repair this object. This method is used for schema migration, when the class definition changes and existing instances of previous versions must be updated. """ pass # nothing to repair at the moment # register security information Globals.InitializeClass(XPathMethod)