simple rss client

.gitignore

@@ -10,3 +10,6 @@ pubspec.lock
 # Directory created by dartdoc
 # If you don't generate documentation locally you can remove this line.
 doc/api/
+
+.idea
+.dart_tool

lib/client.dart

@@ -0,0 +1,25 @@
+import 'dart:async';
+
+import 'package:http/http.dart' as http;
+import 'package:webfeedclient/domain/channel.dart';
+import 'package:xml/xml.dart' as xml;
+
+class WebFeedClient {
+  http.Client client;
+
+  WebFeedClient() {
+    client = new http.Client();
+  }
+
+  Future<Channel> fetch(String url) {
+    return client.get(url).then((response) {
+      print("Response Status Code: ${response.statusCode}");
+      print("Response Body: ${response.body}");
+      return response.body;
+    }).then((bodyString) {
+      var document = xml.parse(bodyString);
+      var channel = new Channel.parse(document);
+      return channel;
+    });
+  }
+}

lib/domain/channel.dart

@@ -0,0 +1,70 @@
+import 'dart:core';
+
+import 'package:webfeedclient/domain/item.dart';
+import 'package:webfeedclient/util/helpers.dart';
+import 'package:xml/xml.dart';
+
+import 'image.dart';
+
+class Channel {
+  final String title;
+  final String description;
+  final String link;
+  final List<Item> items;
+
+  final Image image;
+  final String lastBuildDate;
+  final String language;
+  final String generator;
+  final String copyright;
+
+  Channel(this.title, this.description, this.link, this.items,
+      {this.image, this.lastBuildDate, this.language, this.generator, this.copyright});
+
+  factory Channel.parse(XmlDocument document) {
+    XmlElement channelElement;
+    try {
+      channelElement = document
+          .findAllElements("channel")
+          .first;
+    } on StateError {
+      throw new ArgumentError("channel not found");
+    }
+    var title = xmlGetString(channelElement, "title");
+    var description = xmlGetString(channelElement, "description");
+    var link = xmlGetString(channelElement, "link");
+
+    var feeds = channelElement.findAllElements("item").map((XmlElement element) {
+      return new Item.parse(element);
+    }).toList();
+
+    Image image;
+    try {
+      image = new Image.parse(channelElement
+          .findElements("image")
+          .first);
+    } on StateError {}
+
+    var lastBuildDate = xmlGetString(channelElement, "lastBuildDate", strict: false);
+    var language = xmlGetString(channelElement, "language", strict: false);
+    var generator = xmlGetString(channelElement, "generator", strict: false);
+    var copyright = xmlGetString(channelElement, "copyright", strict: false);
+
+    return new Channel(title, description, link, feeds, image: image,
+        lastBuildDate: lastBuildDate,
+        language: language,
+        generator: generator,
+        copyright: copyright);
+  }
+
+  @override
+  String toString() {
+    return '''
+      title: $title
+      description: $description
+      link: $link
+      lastBuildDate: $lastBuildDate
+      items: $items
+    ''';
+  }
+}

lib/domain/image.dart

@@ -0,0 +1,27 @@
+import 'package:webfeedclient/util/helpers.dart';
+import 'package:xml/xml.dart';
+
+class Image {
+  final String title;
+  final String url;
+  final String link;
+
+  Image(this.title, this.url, this.link);
+
+  factory Image.parse(XmlElement element) {
+    var title = xmlGetString(element, "title", strict: false);
+    var url = xmlGetString(element, "url", strict: false);
+    var link = xmlGetString(element, "link", strict: false);
+
+    return new Image(title, url, link);
+  }
+
+  @override
+  String toString() {
+    return '''
+      title: $title
+      url: $url
+      link: $link
+    ''';
+  }
+}

lib/domain/item.dart

@@ -0,0 +1,33 @@
+import 'package:webfeedclient/util/helpers.dart';
+import 'package:xml/xml.dart';
+
+class Item {
+  final String title;
+  final String description;
+  final String link;
+  final String guid;
+  final String pubDate;
+
+  Item(this.title, this.description, this.link, {this.guid, this.pubDate});
+
+  factory Item.parse(XmlElement element) {
+    var title = xmlGetString(element, "title");
+    var description = xmlGetString(element, "description");
+    var link = xmlGetString(element, "link");
+
+    var guid = xmlGetString(element, "guid", strict: false);
+    var pubDate = xmlGetString(element, "pubDate", strict: false);
+
+    return new Item(title, description, link, guid: guid, pubDate: pubDate);
+  }
+
+  @override
+  String toString() {
+    return '''
+      title: $title
+      description: $description
+      link: $link
+      pubDate: $pubDate
+    ''';
+  }
+}

lib/main.dart

@@ -0,0 +1,6 @@
+import 'package:webfeedclient/client.dart';
+
+void main() {
+  var client = new WebFeedClient();
+  client.fetch("https://developer.apple.com/news/releases/rss/releases.rss");
+}

lib/util/helpers.dart

@@ -0,0 +1,17 @@
+import 'dart:core';
+
+import 'package:xml/xml.dart';
+
+String xmlGetString(XmlElement element, String name, {strict: true}) {
+  try {
+    return element
+        .findElements(name)
+        .first
+        .text;
+  } on StateError {
+    if (strict) {
+      throw new ArgumentError("$name not found");
+    }
+  }
+  return null;
+}

pubspec.yaml

@@ -0,0 +1,6 @@
+name: webfeedclient
+dependencies:
+  xml: "^3.0.0"
+  http: "^0.11.3+16"
+dev_dependencies:
+  test: ^0.12.0

test/examples/Invalid.xml

@@ -0,0 +1,2 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<foo></foo>

test/examples/RSS.xml

@@ -0,0 +1,31 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<rss version="2.0">
+    <channel>
+        <title>News - Foo bar News</title>
+        <link>https://foo.bar.news/</link>
+        <description>Foo bar News and Updates feed provided by Foo bar, Inc.</description>
+        <image>
+            <url>https://foo.bar.news/logo.gif</url>
+            <title>Foo bar News</title>
+            <link>https://foo.bar.news/</link>
+        </image>
+        <language>en-US</language>
+        <lastBuildDate>Mon, 26 Mar 2018 14:00:00 PDT</lastBuildDate>
+        <generator>Custom</generator>
+        <copyright>Copyright 2018, Foo bar Inc.</copyright>
+        <item>
+            <title>The standard Lorem Ipsum passage, used since the 1500s</title>
+            <link>https://foo.bar.news/1</link>
+            <guid>https://foo.bar.news/1?guid</guid>
+            <description>Lorem ipsum dolor sit amet, consectetur adipiscing elit</description>
+            <pubDate>Mon, 26 Mar 2018 14:00:00 PDT</pubDate>
+        </item>
+        <item>
+            <title>Section 1.10.32 of "de Finibus Bonorum et Malorum", written by Cicero in 45 BC</title>
+            <link>https://foo.bar.news/2</link>
+            <guid>https://foo.bar.news/2?guid</guid>
+            <description>Sed ut perspiciatis unde omnis iste natus error sit voluptatem accusantium doloremque laudantium</description>
+            <pubDate>Tue, 20 Mar 2018 10:00:00 PDT</pubDate>
+        </item>
+    </channel>
+</rss>

test/rss.dart

@@ -0,0 +1,43 @@
+import 'dart:io';
+import 'dart:core';
+import 'package:test/test.dart';
+import 'package:webfeedclient/domain/channel.dart';
+import 'package:xml/xml.dart' as xml;
+
+void main() {
+  test("parsing Invalid.xml", () {
+    var xmlString = new File("test/examples/Invalid.xml").readAsStringSync();
+    var doc = xml.parse(xmlString);
+
+    try {
+      new Channel.parse(doc);
+      fail("Should throw Argument Error");
+    } on ArgumentError {}
+  });
+  test("parsing RSS.xml", () {
+    var xmlString = new File("test/examples/RSS.xml").readAsStringSync();
+    var doc = xml.parse(xmlString);
+
+    var channel = new Channel.parse(doc);
+
+    expect(channel.title, "News - Foo bar News");
+    expect(channel.description, "Foo bar News and Updates feed provided by Foo bar, Inc.");
+    expect(channel.link, "https://foo.bar.news/");
+    expect(channel.language, "en-US");
+    expect(channel.lastBuildDate, "Mon, 26 Mar 2018 14:00:00 PDT");
+    expect(channel.generator, "Custom");
+    expect(channel.copyright, "Copyright 2018, Foo bar Inc.");
+
+    expect(channel.image.title, "Foo bar News");
+    expect(channel.image.url, "https://foo.bar.news/logo.gif");
+    expect(channel.image.link, "https://foo.bar.news/");
+
+    expect(channel.items.length, 2);
+
+    expect(channel.items.first.title, "The standard Lorem Ipsum passage, used since the 1500s");
+    expect(channel.items.first.description, "Lorem ipsum dolor sit amet, consectetur adipiscing elit");
+    expect(channel.items.first.link, "https://foo.bar.news/1");
+    expect(channel.items.first.guid, "https://foo.bar.news/1?guid");
+    expect(channel.items.first.pubDate, "Mon, 26 Mar 2018 14:00:00 PDT");
+  });
+}