Mercurial > libervia-backend
diff src/memory/params.py @ 914:1a3ba959f0ab
core (memory): moved Params in its own module + introduced a new core/constants module, and moved some constants there
author | Goffi <goffi@goffi.org> |
---|---|
date | Fri, 21 Mar 2014 16:08:11 +0100 |
parents | src/memory/memory.py@fab49a1d5ea2 |
children | 1a759096ccbd |
line wrap: on
line diff
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/memory/params.py Fri Mar 21 16:08:11 2014 +0100 @@ -0,0 +1,673 @@ +#!/usr/bin/python +# -*- coding: utf-8 -*- + +# SAT: a jabber client +# Copyright (C) 2009, 2010, 2011, 2012, 2013, 2014 Jérôme Poisson (goffi@goffi.org) + +# This program is free software: you can redistribute it and/or modify +# it under the terms of the GNU Affero General Public License as published by +# the Free Software Foundation, either version 3 of the License, or +# (at your option) any later version. + +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU Affero General Public License for more details. + +# You should have received a copy of the GNU Affero General Public License +# along with this program. If not, see <http://www.gnu.org/licenses/>. + +from sat.core.i18n import _ + +from sat.core import exceptions +from sat.core.constants import Const as C +from xml.dom import minidom +from logging import debug, info, warning, error +from twisted.internet import defer +from twisted.python.failure import Failure +from sat.tools.xml_tools import paramsXML2XMLUI + + +class Params(object): + """This class manage parameters with xml""" + ### TODO: add desciption in params + + #TODO: move Watched in a plugin + #TODO: when priority is changed, a new presence stanza must be emitted + #TODO: int type (Priority should be int instead of string) + default_xml = u""" + <params> + <general> + </general> + <individual> + <category name="Connection" label="%(category_connection)s"> + <param name="JabberID" value="name@example.org/SàT" type="string" /> + <param name="Password" value="" type="password" /> + <param name="Priority" value="50" type="string" /> + <param name="Server" value="example.org" type="string" /> + <param name="Port" value="5222" type="string" /> + <param name="NewAccount" label="%(label_NewAccount)s" type="button" callback_id="registerNewAccount"/> + <param name="autoconnect" label="%(label_autoconnect)s" value="true" type="bool" /> + <param name="autodisconnect" label="%(label_autodisconnect)s" value="false" type="bool" /> + </category> + <category name="Misc" label="%(category_misc)s"> + <param name="Watched" value="test@Jabber.goffi.int" type="string" /> + </category> + </individual> + </params> + """ % { + 'category_connection': _("Connection"), + 'label_NewAccount': _("Register new account"), + 'label_autoconnect': _('Connect on frontend startup'), + 'label_autodisconnect': _('Disconnect on frontend closure'), + 'category_misc': _("Misc") + } + + def load_default_params(self): + self.dom = minidom.parseString(Params.default_xml.encode('utf-8')) + + def _mergeParams(self, source_node, dest_node): + """Look for every node in source_node and recursively copy them to dest if they don't exists""" + + def getNodesMap(children): + ret = {} + for child in children: + if child.nodeType == child.ELEMENT_NODE: + ret[(child.tagName, child.getAttribute('name'))] = child + return ret + source_map = getNodesMap(source_node.childNodes) + dest_map = getNodesMap(dest_node.childNodes) + source_set = set(source_map.keys()) + dest_set = set(dest_map.keys()) + to_add = source_set.difference(dest_set) + + for node_key in to_add: + dest_node.appendChild(source_map[node_key].cloneNode(True)) + + to_recurse = source_set - to_add + for node_key in to_recurse: + self._mergeParams(source_map[node_key], dest_map[node_key]) + + def load_xml(self, xml_file): + """Load parameters template from file""" + self.dom = minidom.parse(xml_file) + default_dom = minidom.parseString(Params.default_xml.encode('utf-8')) + self._mergeParams(default_dom.documentElement, self.dom.documentElement) + + def loadGenParams(self): + """Load general parameters data from storage + @return: deferred triggered once params are loaded""" + return self.storage.loadGenParams(self.params_gen) + + def loadIndParams(self, profile, cache=None): + """Load individual parameters + set self.params cache or a temporary cache + @param profile: profile to load (*must exist*) + @param cache: if not None, will be used to store the value, as a short time cache + @return: deferred triggered once params are loaded""" + if cache is None: + self.params[profile] = {} + return self.storage.loadIndParams(self.params[profile] if cache is None else cache, profile) + + def purgeProfile(self, profile): + """Remove cache data of a profile + @param profile: %(doc_profile)s""" + try: + del self.params[profile] + except KeyError: + error(_("Trying to purge cache of a profile not in memory: [%s]") % profile) + + def save_xml(self, filename): + """Save parameters template to xml file""" + with open(filename, 'wb') as xml_file: + xml_file.write(self.dom.toxml('utf-8')) + + def __init__(self, host, storage): + debug("Parameters init") + self.host = host + self.storage = storage + self.default_profile = None + self.params = {} + self.params_gen = {} + host.registerCallback(host.registerNewAccountCB, with_data=True, force_id="registerNewAccount") + + def asyncCreateProfile(self, profile): + """Create a new profile + @param profile: name of the profile + @param callback: called when the profile actually exists in database and memory + @return: a Deferred instance + """ + if self.storage.hasProfile(profile): + info(_('The profile name already exists')) + return defer.fail(Failure(exceptions.ConflictError)) + if not self.host.trigger.point("ProfileCreation", profile): + return defer.fail(Failure(exceptions.CancelError)) + return self.storage.createProfile(profile) + + def asyncDeleteProfile(self, profile, force=False): + """Delete an existing profile + @param profile: name of the profile + @param force: force the deletion even if the profile is connected. + To be used for direct calls only (not through the bridge). + @return: a Deferred instance + """ + if not self.storage.hasProfile(profile): + info(_('Trying to delete an unknown profile')) + return defer.fail(Failure(exceptions.ProfileUnknownError)) + if not force and self.host.isConnected(profile): + info(_("Trying to delete a connected profile")) + return defer.fail(Failure(exceptions.ConnectedProfileError)) + return self.storage.deleteProfile(profile) + + def getProfileName(self, profile_key, return_profile_keys = False): + """return profile according to profile_key + @param profile_key: profile name or key which can be + @ALL@ for all profiles + @DEFAULT@ for default profile + @param return_profile_keys: if True, return unmanaged profile keys (like "@ALL@"). This keys must be managed by the caller + @return: requested profile name or emptry string if it doesn't exist""" + if profile_key == '@DEFAULT@': + default = self.host.memory.memory_data.get('Profile_default') + if not default: + info(_('No default profile, returning first one')) # TODO: manage real default profile + try: + default = self.host.memory.memory_data['Profile_default'] = self.storage.getProfilesList()[0] + except IndexError: + info(_('No profile exist yet')) + return "" + return default # FIXME: temporary, must use real default value, and fallback to first one if it doesn't exists + elif profile_key == '@NONE@': + raise exceptions.ProfileNotSetError + elif return_profile_keys and profile_key in ["@ALL@"]: + return profile_key # this value must be managed by the caller + if not self.storage.hasProfile(profile_key): + info(_('Trying to access an unknown profile')) + return "" # FIXME: raise exceptions.ProfileUnknownError here (must be well checked, this method is used in lot of places) + return profile_key + + def __get_unique_node(self, parent, tag, name): + """return node with given tag + @param parent: parent of nodes to check (e.g. documentElement) + @param tag: tag to check (e.g. "category") + @param name: name to check (e.g. "JID") + @return: node if it exist or None + """ + for node in parent.childNodes: + if node.nodeName == tag and node.getAttribute("name") == name: + #the node already exists + return node + #the node is new + return None + + def updateParams(self, xml, security_limit=C.NO_SECURITY_LIMIT, app=''): + """import xml in parameters, update if the param already exists + If security_limit is specified and greater than -1, the parameters + that have a security level greater than security_limit are skipped. + @param xml: parameters in xml form + @param security_limit: -1 means no security, 0 is the maximum security then the higher the less secure + @param app: name of the frontend registering the parameters or empty value + """ + src_parent = minidom.parseString(xml.encode('utf-8')).documentElement + + def pre_process_app_node(src_parent, security_limit, app): + """Parameters that are registered from a frontend must be checked""" + to_remove = [] + for type_node in src_parent.childNodes: + if type_node.nodeName != C.INDIVIDUAL: + to_remove.append(type_node) # accept individual parameters only + continue + for cat_node in type_node.childNodes: + if cat_node.nodeName != 'category': + to_remove.append(cat_node) + continue + to_remove_count = 0 # count the params to be removed from current category + for node in cat_node.childNodes: + if node.nodeName != "param" or not self.checkSecurityLimit(node, security_limit): + to_remove.append(node) + to_remove_count += 1 + continue + node.setAttribute('app', app) + if len(cat_node.childNodes) == to_remove_count: # remove empty category + for dummy in xrange(0, to_remove_count): + to_remove.pop() + to_remove.append(cat_node) + for node in to_remove: + node.parentNode.removeChild(node) + + def import_node(tgt_parent, src_parent): + for child in src_parent.childNodes: + if child.nodeName == '#text': + continue + node = self.__get_unique_node(tgt_parent, child.nodeName, child.getAttribute("name")) + if not node: # The node is new + tgt_parent.appendChild(child) + else: + if child.nodeName == "param": + # The child updates an existing parameter, we replace the node + tgt_parent.replaceChild(child, node) + else: + # the node already exists, we recurse 1 more level + import_node(node, child) + + if app: + pre_process_app_node(src_parent, security_limit, app) + import_node(self.dom.documentElement, src_parent) + + def paramsRegisterApp(self, xml, security_limit, app): + """Register frontend's specific parameters + If security_limit is specified and greater than -1, the parameters + that have a security level greater than security_limit are skipped. + @param xml: XML definition of the parameters to be added + @param security_limit: -1 means no security, 0 is the maximum security then the higher the less secure + @param app: name of the frontend registering the parameters + """ + if not app: + warning(_("Trying to register frontends parameters with no specified app: aborted")) + return + if not hasattr(self, "frontends_cache"): + self.frontends_cache = [] + if app in self.frontends_cache: + debug(_("Trying to register twice frontends parameters for %(app)s: aborted" % {"app": app})) + return + self.frontends_cache.append(app) + self.updateParams(xml, security_limit, app) + debug("Frontends parameters registered for %(app)s" % {'app': app}) + + def __default_ok(self, value, name, category): + #FIXME: will not work with individual parameters + self.setParam(name, value, category) + + def __default_ko(self, failure, name, category): + error(_("Can't determine default value for [%(category)s/%(name)s]: %(reason)s") % {'category': category, 'name': name, 'reason': str(failure.value)}) + + def setDefault(self, name, category, callback, errback=None): + """Set default value of parameter + 'default_cb' attibute of parameter must be set to 'yes' + @param name: name of the parameter + @param category: category of the parameter + @param callback: must return a string with the value (use deferred if needed) + @param errback: must manage the error with args failure, name, category + """ + #TODO: send signal param update if value changed + #TODO: manage individual paramaters + debug ("setDefault called for %(category)s/%(name)s" % {"category": category, "name": name}) + node = self._getParamNode(name, category, '@ALL@') + if not node: + error(_("Requested param [%(name)s] in category [%(category)s] doesn't exist !") % {'name': name, 'category': category}) + return + if node[1].getAttribute('default_cb') == 'yes': + # del node[1].attributes['default_cb'] # default_cb is not used anymore as a flag to know if we have to set the default value, + # and we can still use it later e.g. to call a generic setDefault method + value = self._getParam(category, name, C.GENERAL) + if value is None: # no value set by the user: we have the default value + debug ("Default value to set, using callback") + d = defer.maybeDeferred(callback) + d.addCallback(self.__default_ok, name, category) + d.addErrback(errback or self.__default_ko, name, category) + + def _getAttr(self, node, attr, value): + """ get attribute value + @param node: XML param node + @param attr: name of the attribute to get (e.g.: 'value' or 'type') + @param value: user defined value""" + if attr == 'value': + value_to_use = value if value is not None else node.getAttribute(attr) # we use value (user defined) if it exist, else we use node's default value + if node.getAttribute('type') == 'bool': + return value_to_use.lower() not in ('false', '0', 'no') + return value_to_use + return node.getAttribute(attr) + + def __type_to_string(self, result): + """ convert result to string, according to its type """ + if isinstance(result, bool): + return "true" if result else "false" + return result + + def getStringParamA(self, name, category, attr="value", profile_key="@NONE@"): + """ Same as getParamA but for bridge: convert non string value to string """ + return self.__type_to_string(self.getParamA(name, category, attr, profile_key)) + + def getParamA(self, name, category, attr="value", profile_key="@NONE@"): + """Helper method to get a specific attribute + @param name: name of the parameter + @param category: category of the parameter + @param attr: name of the attribute (default: "value") + @param profile: owner of the param (@ALL@ for everyone) + + @return: attribute""" + #FIXME: looks really dirty and buggy, need to be reviewed/refactored + node = self._getParamNode(name, category) + if not node: + error(_("Requested param [%(name)s] in category [%(category)s] doesn't exist !") % {'name': name, 'category': category}) + raise exceptions.NotFound + + if node[0] == C.GENERAL: + value = self._getParam(category, name, C.GENERAL) + return self._getAttr(node[1], attr, value) + + assert node[0] == C.INDIVIDUAL + + profile = self.getProfileName(profile_key) + if not profile: + error(_('Requesting a param for an non-existant profile')) + raise exceptions.ProfileUnknownError + + if profile not in self.params: + error(_('Requesting synchronous param for not connected profile')) + raise exceptions.NotConnectedProfileError(profile) + + if attr == "value": + value = self._getParam(category, name, profile=profile) + return self._getAttr(node[1], attr, value) + + def asyncGetStringParamA(self, name, category, attr="value", security_limit=C.NO_SECURITY_LIMIT, profile_key="@NONE@"): + d = self.asyncGetParamA(name, category, attr, security_limit, profile_key) + d.addCallback(self.__type_to_string) + return d + + def asyncGetParamA(self, name, category, attr="value", security_limit=C.NO_SECURITY_LIMIT, profile_key="@NONE@"): + """Helper method to get a specific attribute + @param name: name of the parameter + @param category: category of the parameter + @param attr: name of the attribute (default: "value") + @param profile: owner of the param (@ALL@ for everyone)""" + node = self._getParamNode(name, category) + if not node: + error(_("Requested param [%(name)s] in category [%(category)s] doesn't exist !") % {'name': name, 'category': category}) + return None + + if not self.checkSecurityLimit(node[1], security_limit): + warning(_("Trying to get parameter '%(param)s' in category '%(cat)s' without authorization!!!" + % {'param': name, 'cat': category})) + return None + + if node[0] == C.GENERAL: + value = self._getParam(category, name, C.GENERAL) + return defer.succeed(self._getAttr(node[1], attr, value)) + + assert node[0] == C.INDIVIDUAL + + profile = self.getProfileName(profile_key) + if not profile: + error(_('Requesting a param for a non-existant profile')) + return defer.fail() + + if attr != "value": + return defer.succeed(node[1].getAttribute(attr)) + try: + value = self._getParam(category, name, profile=profile) + return defer.succeed(self._getAttr(node[1], attr, value)) + except exceptions.ProfileNotInCacheError: + #We have to ask data to the storage manager + d = self.storage.getIndParam(category, name, profile) + return d.addCallback(lambda value: self._getAttr(node[1], attr, value)) + + def _getParam(self, category, name, type_=C.INDIVIDUAL, cache=None, profile="@NONE@"): + """Return the param, or None if it doesn't exist + @param category: param category + @param name: param name + @param type_: GENERAL or INDIVIDUAL + @param cache: temporary cache, to use when profile is not logged + @param profile: the profile name (not profile key, i.e. name and not something like @DEFAULT@) + @return: param value or None if it doesn't exist + """ + if type_ == C.GENERAL: + if (category, name) in self.params_gen: + return self.params_gen[(category, name)] + return None # This general param has the default value + assert (type_ == C.INDIVIDUAL) + if profile == "@NONE@": + raise exceptions.ProfileNotSetError + if profile in self.params: + cache = self.params[profile] # if profile is in main cache, we use it, + # ignoring the temporary cache + elif cache is None: # else we use the temporary cache if it exists, or raise an exception + raise exceptions.ProfileNotInCacheError + if (category, name) not in cache: + return None + return cache[(category, name)] + + def __constructProfileXml(self, security_limit, app, profile): + """Construct xml for asked profile, filling values when needed + /!\ as noticed in doc, don't forget to unlink the minidom.Document + @param security_limit: NO_SECURITY_LIMIT (-1) to return all the params. + Otherwise sole the params which have a security level defined *and* + lower or equal to the specified value are returned. + @param app: name of the frontend requesting the parameters, or '' to get all parameters + @param profile: profile name (not key !) + @return: a deferred that fire a minidom.Document of the profile xml (cf warning above) + """ + + def checkNode(node): + """Check the node against security_limit and app""" + return self.checkSecurityLimit(node, security_limit) and self.checkApp(node, app) + + def constructProfile(ignore, profile_cache): + # init the result document + prof_xml = minidom.parseString('<params/>') + cache = {} + + for type_node in self.dom.documentElement.childNodes: + if type_node.nodeName != C.GENERAL and type_node.nodeName != C.INDIVIDUAL: + continue + # we use all params, general and individual + for cat_node in type_node.childNodes: + if cat_node.nodeName != 'category': + continue + category = cat_node.getAttribute('name') + dest_params = {} # result (merged) params for category + if category not in cache: + # we make a copy for the new xml + cache[category] = dest_cat = cat_node.cloneNode(True) + for node in dest_cat.childNodes: + if node.nodeName != "param": + continue + if not checkNode(node): + dest_cat.removeChild(node) + continue + dest_params[node.getAttribute('name')] = node + new_node = True + else: + # It's not a new node, we use the previously cloned one + dest_cat = cache[category] + new_node = False + params = cat_node.getElementsByTagName("param") + + for param_node in params: + # we have to merge new params (we are parsing individual parameters, we have to add them + # to the previously parsed general ones) + name = param_node.getAttribute('name') + if not checkNode(param_node): + continue + if name not in dest_params: + # this is reached when a previous category exists + dest_params[name] = param_node.cloneNode(True) + dest_cat.appendChild(dest_params[name]) + + profile_value = self._getParam(category, + name, type_node.nodeName, + cache=profile_cache, profile=profile) + if profile_value is not None: + # there is a value for this profile, we must change the default + dest_params[name].setAttribute('value', profile_value) + if new_node: + prof_xml.documentElement.appendChild(dest_cat) + + to_remove = [] + for cat_node in prof_xml.documentElement.childNodes: + # we remove empty categories + if cat_node.getElementsByTagName("param").length == 0: + to_remove.append(cat_node) + for node in to_remove: + prof_xml.documentElement.removeChild(node) + return prof_xml + + if profile in self.params: + d = defer.succeed(None) + profile_cache = self.params[profile] + else: + #profile is not in cache, we load values in a short time cache + profile_cache = {} + d = self.loadIndParams(profile, profile_cache) + + return d.addCallback(constructProfile, profile_cache) + + def getParamsUI(self, security_limit, app, profile_key): + """ + @param security_limit: NO_SECURITY_LIMIT (-1) to return all the params. + Otherwise sole the params which have a security level defined *and* + lower or equal to the specified value are returned. + @param app: name of the frontend requesting the parameters, or '' to get all parameters + @param profile_key: Profile key which can be either a magic (eg: @DEFAULT@) or the name of an existing profile. + @return: a SàT XMLUI for parameters + """ + profile = self.getProfileName(profile_key) + if not profile: + error(_("Asking params for inexistant profile")) + return "" + d = self.getParams(security_limit, app, profile) + return d.addCallback(lambda param_xml: paramsXML2XMLUI(param_xml)) + + def getParams(self, security_limit, app, profile_key): + """Construct xml for asked profile, take params xml as skeleton + @param security_limit: NO_SECURITY_LIMIT (-1) to return all the params. + Otherwise sole the params which have a security level defined *and* + lower or equal to the specified value are returned. + @param app: name of the frontend requesting the parameters, or '' to get all parameters + @param profile_key: Profile key which can be either a magic (eg: @DEFAULT@) or the name of an existing profile. + @return: XML of parameters + """ + profile = self.getProfileName(profile_key) + if not profile: + error(_("Asking params for inexistant profile")) + return defer.succeed("") + + def returnXML(prof_xml): + return_xml = prof_xml.toxml() + prof_xml.unlink() + return '\n'.join((line for line in return_xml.split('\n') if line)) + + return self.__constructProfileXml(security_limit, app, profile).addCallback(returnXML) + + def getParamsForCategory(self, category, security_limit, app, profile_key): + """ + @param category: the desired category + @param security_limit: NO_SECURITY_LIMIT (-1) to return all the params. + Otherwise sole the params which have a security level defined *and* + lower or equal to the specified value are returned. + @param app: name of the frontend requesting the parameters, or '' to get all parameters + @param profile_key: Profile key which can be either a magic (eg: @DEFAULT@) or the name of an existing profile. + @return: node's xml for selected category + """ + #TODO: manage category of general type (without existant profile) + profile = self.getProfileName(profile_key) + if not profile: + error(_("Asking params for inexistant profile")) + return "" + + def returnCategoryXml(prof_xml): + for node in prof_xml.getElementsByTagName("category"): + if node.nodeName == "category" and node.getAttribute("name") == category: + result = node.toxml() + prof_xml.unlink() + return result + + prof_xml.unlink() + return "<category />" + + d = self.__constructProfileXml(security_limit, app, profile) + return d.addCallback(returnCategoryXml) + + def _getParamNode(self, name, category, type_="@ALL@"): # FIXME: is type_ useful ? + """Return a node from the param_xml + @param name: name of the node + @param category: category of the node + @type_: keyword for search: + @ALL@ search everywhere + @GENERAL@ only search in general type + @INDIVIDUAL@ only search in individual type + @return: a tuple with the node type and the the node, or None if not found""" + + for type_node in self.dom.documentElement.childNodes: + if (((type_ == "@ALL@" or type_ == "@GENERAL@") and type_node.nodeName == C.GENERAL) + or ((type_ == "@ALL@" or type_ == "@INDIVIDUAL@") and type_node.nodeName == C.INDIVIDUAL)): + for node in type_node.getElementsByTagName('category'): + if node.getAttribute("name") == category: + params = node.getElementsByTagName("param") + for param in params: + if param.getAttribute("name") == name: + return (type_node.nodeName, param) + return None + + def getParamsCategories(self): + """return the categories availables""" + categories = [] + for cat in self.dom.getElementsByTagName("category"): + name = cat.getAttribute("name") + if name not in categories: + categories.append(cat.getAttribute("name")) + return categories + + def setParam(self, name, value, category, security_limit=C.NO_SECURITY_LIMIT, profile_key='@NONE@'): + """Set a parameter, return None if the parameter is not in param xml""" + #TODO: use different behaviour depending of the data type (e.g. password encrypted) + if profile_key != "@NONE@": + profile = self.getProfileName(profile_key) + if not profile: + error(_('Trying to set parameter for an unknown profile')) + return # TODO: throw an error + + node = self._getParamNode(name, category, '@ALL@') + if not node: + error(_('Requesting an unknown parameter (%(category)s/%(name)s)') + % {'category': category, 'name': name}) + return + + if not self.checkSecurityLimit(node[1], security_limit): + warning(_("Trying to set parameter '%(param)s' in category '%(cat)s' without authorization!!!" + % {'param': name, 'cat': category})) + return + + if node[0] == C.GENERAL: + self.params_gen[(category, name)] = value + self.storage.setGenParam(category, name, value) + for profile in self.storage.getProfilesList(): + if self.host.isConnected(profile): + self.host.bridge.paramUpdate(name, value, category, profile) + self.host.trigger.point("paramUpdateTrigger", name, value, category, node[0], profile) + return + + assert (node[0] == C.INDIVIDUAL) + assert (profile_key != "@NONE@") + + type_ = node[1].getAttribute("type") + if type_ == "button": + print "clique", node.toxml() + else: + if self.host.isConnected(profile): # key can not exists if profile is not connected + self.params[profile][(category, name)] = value + self.host.bridge.paramUpdate(name, value, category, profile) + self.host.trigger.point("paramUpdateTrigger", name, value, category, node[0], profile) + self.storage.setIndParam(category, name, value, profile) + + def checkSecurityLimit(self, node, security_limit): + """Check the given node against the given security limit. + The value NO_SECURITY_LIMIT (-1) means that everything is allowed. + @return: True if this node can be accessed with the given security limit. + """ + if security_limit < 0: + return True + if node.hasAttribute("security"): + if int(node.getAttribute("security")) <= security_limit: + return True + return False + + def checkApp(self, node, app): + """Check the given node against the given app. + @param node: parameter node + @param app: name of the frontend requesting the parameters, or '' to get all parameters + @return: True if this node concerns the given app. + """ + if not app or not node.hasAttribute("app"): + return True + return node.getAttribute("app") == app