1 files changed, 57 insertions, 0 deletions
diff --git a/rss/rss_feed.py b/rss/rss_feed.py
new file mode 100644
index 00000000..5ed6226d
--- /dev/null
+++ b/rss/rss_feed.py
@@ -0,0 +1,57 @@
+#!/usr/bin/env python3
+
+import lxml.etree as ET
+
+class RssFeed(object):
+    """Class for storing an RSS 2.0 feed.
+
+    https://validator.w3.org/feed/docs/rss2.html.
+
+    """
+
+    # pylint: disable=too-many-instance-attributes
+
+    REQUIRED_ELEMENTS = ["title", "link", "description"]
+    OPTIONAL_ELEMENTS = ["language", "copyright", "managingEditor", "webMaster",
+                         "pubDate", "lastBuildDate", "category", "generator",
+                         "docs", "cloud", "ttl", "image", "textInput",
+                         "skipHours", "skipDays"]
+
+    def __init__(self):
+        """Define available attributes."""
+        self.rssurl = None  # the URL of the rss feed
+        self.atomlink = None
+        for element in self.REQUIRED_ELEMENTS:
+            setattr(self, element, None)
+        for element in self.OPTIONAL_ELEMENTS:
+            setattr(self, element, None)
+        self.docs = ET.Element("docs")
+        self.docs.text = "https://validator.w3.org/feed/docs/rss2.html"
+        self.author_text = None
+        self.update_timestamp = None
+        self.items = []
+        self.rss = None
+        self.channel = None
+
+    def assemble_rss(self, FEED_MAX_ENTRIES):
+        """Assemble RSS 2.0 feed."""
+        self.rss = ET.Element("rss", version="2.0", nsmap={"atom": "http://www.w3.org/2005/Atom"})
+        self.channel = ET.SubElement(self.rss, "channel")
+        # https://validator.w3.org/feed/docs/warning/MissingAtomSelfLink.html
+        self.atomlink = ET.SubElement(self.channel, "{http://www.w3.org/2005/Atom}link",
+                                      href=self.rssurl, rel="self", type="application/rss+xml")
+        for element in self.REQUIRED_ELEMENTS:
+            self.channel.append(getattr(self, element))
+        for element in self.OPTIONAL_ELEMENTS:
+            attr = getattr(self, element)
+            if attr is not None:
+                self.channel.append(attr)
+        # include at most FEED_MAX_ENTRIES items in the RSS feed
+        for item in self.items[:FEED_MAX_ENTRIES]:
+            self.channel.append(item.item)
+
+    def dump_rss(self, FEED_MAX_ENTRIES):
+        """Dump RSS feed XML."""
+        if self.rss is None:
+            self.assemble_rss(FEED_MAX_ENTRIES)
+        return ET.tostring(self.rss).decode("utf-8")