Merge pull request #24 from backlineint/rss-filters

Add filters for RSS Feeds

Author: zachleat

.eleventy.js

@@ -1,5 +1,6 @@
 const pkg = require("./package.json");
 const dateRfc3339 = require("./src/dateRfc3339");
+const dateRfc822 = require("./src/dateRfc822");
 const absoluteUrl = require("./src/absoluteUrl");
 const convertHtmlToAbsoluteUrls = require("./src/htmlToAbsoluteUrls");
 const getNewestCollectionItemDate = require("./src/getNewestCollectionItemDate");
@@ -32,6 +33,7 @@ module.exports = function(eleventyConfig, options = {}) {
   // Dates
   eleventyConfig.addNunjucksFilter("getNewestCollectionItemDate", getNewestCollectionItemDate);
   eleventyConfig.addNunjucksFilter("dateToRfc3339", dateRfc3339);
+  eleventyConfig.addNunjucksFilter("dateToRfc822", dateRfc822);
 
   // Deprecated, these names are incorrect! Issue #8
   eleventyConfig.addNunjucksFilter("rssLastUpdatedDate", collection => {
@@ -43,6 +45,7 @@ module.exports = function(eleventyConfig, options = {}) {
 };
 
 module.exports.dateToRfc3339 = dateRfc3339;
+module.exports.dateToRfc822 = dateRfc822;
 module.exports.getNewestCollectionItemDate = getNewestCollectionItemDate;
 module.exports.absoluteUrl = absoluteUrl;
 module.exports.convertHtmlToAbsoluteUrls = convertHtmlToAbsoluteUrls;

README.md

@@ -2,11 +2,10 @@
 
 # eleventy-plugin-rss 🕚⚡️🎈🐀
 
-A pack of [Eleventy](https://github.com/11ty/eleventy) filters for generating Atom and JSON feeds using the Nunjucks templating engine.
+A pack of [Eleventy](https://github.com/11ty/eleventy) filters for generating Atom, JSON and RSS feeds using the Nunjucks templating engine.
 
-_Note: the plugin is called RSS but does not technically include an example of an RSS feed. Generally feed readers that support RSS also support Atom. If you’d like to contribute an example, a pull request would be welcome!_
 
-See `sample/feed.njk` for an example Atom feed template or `sample/feed.json` for an example JSON feed template.
+See `sample/feed.njk` for an example Atom feed template, `sample/feed.json` for an example JSON feed template, or `sample/feed-rss.njk` for an example JSON feed template.
 
 ## [The full `eleventy-plugin-rss` documentation is on 11ty.dev](https://www.11ty.dev/docs/plugins/rss/).
 

sample/feed-rss.njk

@@ -0,0 +1,36 @@
+---json
+{
+  "permalink": "feed-rss.xml",
+  "eleventyExcludeFromCollections": true,
+  "metadata": {
+    "title": "My Blog about Boats",
+    "subtitle": "I am writing about my experiences as a naval navel-gazer.",
+    "url": "https://example.com/",
+    "feedUrl": "https://example.com/feed-rss.xml",
+    "author": {
+      "name": "Boaty McBoatFace",
+      "email": "[email protected]"
+    }
+  }
+}
+---
+<?xml version="1.0" encoding="utf-8"?>
+<rss version="2.0" xmlns:dc="http://purl.org/dc/elements/1.1/" xml:base="{{ metadata.url }}">
+  <channel>
+    <title>{{ metadata.title }}</title>
+    <link>{{ metadata.url }}</link>
+    <description>{{ metadata.subtitle }}</description>
+    <language>en</language>
+    {%- for post in collections.posts | reverse %}
+        {% set absolutePostUrl %}{{ post.url | url | absoluteUrl(metadata.url) }}{% endset %}
+        <item>
+            <title>{{ post.data.title }}</title>
+            <link>{{ absolutePostUrl }}</link>
+            <description>{{ post.templateContent | htmlToAbsoluteUrls(absolutePostUrl) }}</description>
+            <pubDate>{{ post.date | dateToRfc822 }}</pubDate>
+            <dc:creator>{{ metadata.author.name }}</dc:creator>
+            <guid>{{ absolutePostUrl }}</guid>
+        </item>
+    {%- endfor %}
+  </channel>
+</rss>

src/dateRfc822.js

@@ -0,0 +1,8 @@
+const decompose = require("./decomposeDate");
+
+module.exports = function(date) {
+  const { dayName, day, monthName, year, hours, minutes, seconds } = decompose(
+    date
+  );
+  return `${dayName}, ${day} ${monthName} ${year} ${hours}:${minutes}:${seconds} +0000`;
+};

src/decomposeDate.js

@@ -0,0 +1,47 @@
+const pad = require("./padDate");
+
+const shortDayNames = ['Sun', 'Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat'];
+
+const shortMonthNames = [
+  'Jan',
+  'Feb',
+  'Mar',
+  'Apr',
+  'May',
+  'Jun',
+  'Jul',
+  'Aug',
+  'Sep',
+  'Oct',
+  'Nov',
+  'Dec'
+];
+
+/**
+ * Given a Date object returns decomposed values
+ * @param {Date} date
+ * @returns {Object}
+ */
+module.exports = function(date) {
+  const day = pad(date.getDate(), 2);
+
+  const dayName = shortDayNames[date.getDay()];
+  const month = pad(date.getMonth() + 1, 2);
+  const monthName = shortMonthNames[date.getMonth()];
+  const year = date.getFullYear();
+
+  const hours = pad(date.getHours(), 2);
+  const minutes = pad(date.getMinutes(), 2);
+  const seconds = pad(date.getSeconds(), 2);
+
+  return {
+    day,
+    dayName,
+    month,
+    monthName,
+    year,
+    hours,
+    minutes,
+    seconds
+  };
+};

src/padDate.js

@@ -0,0 +1,12 @@
+/**
+ * Receives a number and a desired length, returns a padded string
+ * @method pad
+ * @param {Number} number
+ * @param {Number} length
+ * @returns {String}
+ */
+module.exports = function(number, length) {
+  let result = number + '';
+  while (result.length < length) result = '0' + result;
+  return result;
+};

test/dateToRfc822.test.js

@@ -0,0 +1,8 @@
+const test = require("ava");
+const dateRfc822 = require("../src/dateRfc822.js");
+
+test('parses date correctly', (t) => {
+  const date = new Date(2015, 9, 21, 7, 28, 2, 450);
+  const parsedDate = dateRfc822(date);
+  t.is(parsedDate, 'Wed, 21 Oct 2015 07:28:02 +0000');
+});