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# Licensed to the Apache Software Foundation (ASF) under one
# or more contributor license agreements. See the NOTICE file
# distributed with this work for additional information
# regarding copyright ownership. The ASF licenses this file
# to you under the Apache License, Version 2.0 (the
# "License"); you may not use this file except in compliance
# with the License. You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing,
# software distributed under the License is distributed on an
# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
# KIND, either express or implied. See the License for the
# specific language governing permissions and limitations
# under the License.
# RSS data conversion functions
from util import *
from elemutil import *
from xmlutil import *
# Convert a list of elements to a list of values representing an RSS entry
def entryElementsToValues(e):
lt = filter(selector((element, "'title")), e)
t = "" if isNil(lt) else elementValue(car(lt))
li = filter(selector((element, "'link")), e)
i = "" if isNil(li) else elementValue(car(li))
lc = filter(selector((element, "'description")), e)
return (t, i, elementValue(car(lc)))
# Convert a list of elements to a list of values representing RSS entries
def entriesElementsToValues(e):
if isNil(e):
return e
return cons(entryElementsToValues(car(e)), entriesElementsToValues(cdr(e)))
# Convert a list of strings to a list of values representing an RSS entry
def readRSSEntry(l):
e = readXML(l)
if isNil(e):
return ()
return entryElementsToValues(car(e))
# Convert a list of values representy an RSS entry to a value
def entryValue(e):
v = elementsToValues((caddr(e),))
return cons(car(e), (cadr(e), cdr(car(v))))
# Return true if a list of strings represents an RSS feed
def isRSSFeed(l):
if not isXML(l):
return False
return contains(car(l), "<rss")
# Convert a list of strings to a list of values representing an RSS feed
def readRSSFeed(l):
f = readXML(l)
if isNil(f):
return ()
c = filter(selector((element, "'channel")), car(f))
t = filter(selector((element, "'title")), car(c))
i = filter(selector((element, "'link")), car(c))
e = filter(selector((element, "'item")), car(c))
if isNil(e):
return (elementValue(car(t)), elementValue(car(i)))
return cons(elementValue(car(t)), cons(elementValue(car(i)), entriesElementsToValues(e)))
# Convert an RSS feed containing elements to an RSS feed containing values
def feedValuesLoop(e):
if (isNil(e)):
return e
return cons(entryValue(car(e)), feedValuesLoop(cdr(e)))
def feedValues(e):
return cons(car(e), cons(cadr(e), feedValuesLoop(cddr(e))))
# Convert a list of values representy an RSS entry to a list of elements
def entryElement(l):
return (element, "'item",
(element, "'title", car(l)),
(element, "'link", cadr(l)),
(element, "'description", caddr(l)))
# Convert a list of values representing RSS entries to a list of elements
def entriesElements(l):
if isNil(l):
return l
return cons(entryElement(car(l)), entriesElements(cdr(l)))
# Convert a list of values representing an RSS entry to an RSS entry
def writeRSSEntry(l):
return writeXML((entryElement(l),), True)
# Convert a list of values representing an RSS feed to an RSS feed
def writeRSSFeed(l):
c = ((element, "'title", car(l)),
(element, "'link", cadr(l)),
(element, "'description", car(l)))
ce = c if isNil(cddr(l)) else append(c, entriesElements(cddr(l)))
fe = (element, "'rss", (attribute, "'version", "2.0"), append((element, "'channel"), ce))
return writeXML((fe,), True)
# Convert an RSS entry containing a value to an RSS entry containing an item element
def entryValuesToElements(v):
return cons(car(v), cons(cadr(v), valuesToElements((cons("'item", caddr(v)),))))
# Convert an RSS feed containing values to an RSS feed containing elements
def feedValuesToElementsLoop(v):
if isNil(v):
return v
return cons(entryValuesToElements(car(v)), feedValuesToElementsLoop(cdr(v)))
def feedValuesToElements(v):
return cons(car(v), cons(cadr(v), feedValuesToElementsLoop(cddr(v))))
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