| # 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)))) |
| |