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Diffstat (limited to 'sandbox/sebastien/cpp/apr-2/modules/rss/rss.hpp')
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diff --git a/sandbox/sebastien/cpp/apr-2/modules/rss/rss.hpp b/sandbox/sebastien/cpp/apr-2/modules/rss/rss.hpp new file mode 100644 index 0000000000..506d1f4a6d --- /dev/null +++ b/sandbox/sebastien/cpp/apr-2/modules/rss/rss.hpp @@ -0,0 +1,201 @@ +/* + * 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. + */ + +/* $Rev$ $Date$ */ + +#ifndef tuscany_rss_hpp +#define tuscany_rss_hpp + +/** + * RSS data conversion functions. + */ + +#include "string.hpp" +#include "list.hpp" +#include "value.hpp" +#include "monad.hpp" +#include "xml.hpp" + +namespace tuscany { +namespace rss { + +/** + * Convert a list of elements to a list of values representing an RSS entry. + */ +const list<value> entryElementsToValues(const list<value>& e) { + const list<value> lt = filter<value>(selector(mklist<value>(element, "title")), e); + const value t = isNil(lt)? value(emptyString) : elementValue(car(lt)); + const list<value> li = filter<value>(selector(mklist<value>(element, "link")), e); + const value i = isNil(li)? value(emptyString) : elementValue(car(li)); + const list<value> ld = filter<value>(selector(mklist<value>(element, "description")), e); + return mklist<value>(t, i, elementValue(car(ld))); +} + +/** + * Convert a list of elements to a list of values representing RSS entries. + */ +const list<value> entriesElementsToValues(const list<value>& e) { + if (isNil(e)) + return e; + return cons<value>(entryElementsToValues(car(e)), entriesElementsToValues(cdr(e))); +} + +/** + * Return true if a list of strings contains an RSS feed. + */ +const bool isRSSFeed(const list<string>& ls) { + if (!isXML(ls)) + return false; + return contains(car(ls), "<rss"); +} + +/** + * Convert a list of strings to a list of values representing an RSS entry. + */ +const failable<list<value> > readRSSEntry(const list<string>& ilist) { + const list<value> e = readXML(ilist); + if (isNil(e)) + return mkfailure<list<value> >("Empty entry"); + return entryElementsToValues(car(e)); +} + +/** + * Convert a list of values representing an RSS entry to a value. + */ +const value entryValue(const list<value>& e) { + const list<value> v = elementsToValues(mklist<value>(caddr(e))); + return cons(car(e), mklist<value>(cadr(e), isList(car(v))? (value)cdr<value>(car(v)) : car(v))); +} + +/** + * Convert a list of strings to a list of values representing an RSS feed. + */ +const failable<list<value> > readRSSFeed(const list<string>& ilist) { + const list<value> f = readXML(ilist); + if (isNil(f)) + return mkfailure<list<value> >("Empty feed"); + const list<value> c = filter<value>(selector(mklist<value>(element, "channel")), car(f)); + const list<value> t = filter<value>(selector(mklist<value>(element, "title")), car(c)); + const list<value> i = filter<value>(selector(mklist<value>(element, "link")), car(c)); + const list<value> e = filter<value>(selector(mklist<value>(element, "item")), car(c)); + if (isNil(e)) + return mklist<value>(elementValue(car(t)), elementValue(car(i))); + return cons<value>(elementValue(car(t)), cons(elementValue(car(i)), entriesElementsToValues(e))); +} + +/** + * Convert an RSS feed containing elements to an RSS feed containing values. + */ +const list<value> feedValuesLoop(const list<value> e) { + if (isNil(e)) + return e; + return cons<value>(entryValue(car(e)), feedValuesLoop(cdr(e))); +} + +const list<value> feedValues(const list<value>& e) { + return cons(car<value>(e), cons<value>(cadr<value>(e), feedValuesLoop(cddr<value>(e)))); +} + +/** + * Convert a list of values representing an RSS entry to a list of elements. + * The first two values in the list are the entry title and id. + */ +const list<value> entryElement(const list<value>& l) { + return list<value>() + + element + "item" + + (list<value>() + element + "title" + car(l)) + + (list<value>() + element + "link" + cadr(l)) + + (list<value>() + element + "description" + caddr(l)); +} + +/** + * Convert a list of values representing RSS entries to a list of elements. + */ +const list<value> entriesElements(const list<value>& l) { + if (isNil(l)) + return l; + return cons<value>(entryElement(car(l)), entriesElements(cdr(l))); +} + +/** + * Convert a list of values representing an RSS entry to an RSS entry. + * The first two values in the list are the entry id and title. + */ +template<typename R> const failable<R> writeRSSEntry(const lambda<R(const string&, const R)>& reduce, const R& initial, const list<value>& l) { + return writeXML<R>(reduce, initial, mklist<value>(entryElement(l))); +} + +const failable<list<string> > writeRSSEntry(const list<value>& l) { + const failable<list<string> > ls = writeRSSEntry<list<string> >(rcons<string>, list<string>(), l); + if (!hasContent(ls)) + return ls; + return reverse(list<string>(content(ls))); +} + +/** + * Convert a list of values representing an RSS feed to an RSS feed. + * The first two values in the list are the feed id and title. + */ +template<typename R> const failable<R> writeRSSFeed(const lambda<R(const string&, const R)>& reduce, const R& initial, const list<value>& l) { + const list<value> c = list<value>() + + (list<value>() + element + "title" + car(l)) + + (list<value>() + element + "link" + cadr(l)) + + (list<value>() + element + "description" + car(l)); + const list<value> ce = isNil(cddr(l))? c : append(c, entriesElements(cddr(l))); + const list<value> fe = list<value>() + + element + "rss" + (list<value>() + attribute + "version" + "2.0") + + append(list<value>() + element + "channel", ce); + return writeXML<R>(reduce, initial, mklist<value>(fe)); +} + +/** + * Convert a list of values representing an RSS feed to a list of strings. + * The first two values in the list are the feed id and title. + */ +const failable<list<string> > writeRSSFeed(const list<value>& l) { + const failable<list<string> > ls = writeRSSFeed<list<string>>(rcons<string>, list<string>(), l); + if (!hasContent(ls)) + return ls; + return reverse(list<string>(content(ls))); +} + +/** + * Convert an RSS entry containing a value to an RSS entry containing an item element. + */ +const list<value> entryValuesToElements(const list<value> val) { + return cons(car(val), cons(cadr(val), valuesToElements(mklist<value>(cons<value>("item", (list<value>)caddr(val)))))); +} + +/** + * Convert an RSS feed containing values to an RSS feed containing elements. + */ +const list<value> feedValuesToElementsLoop(const list<value> val) { + if (isNil(val)) + return val; + return cons<value>(entryValuesToElements(car(val)), feedValuesToElementsLoop(cdr(val))); +} + +const list<value> feedValuesToElements(const list<value>& val) { + return cons(car<value>(val), cons<value>(cadr<value>(val), feedValuesToElementsLoop(cddr<value>(val)))); +} + +} +} + +#endif /* tuscany_rss_hpp */ |