15.2. 导入Feeds
Zend_Feed 能让开发者轻松获得 Feeds 。如果你知道 Feeds 的URI，用Zend_Feed::import()方法就可以非常容易的获得它:
<?php
$feed = Zend_Feed::import('Http://feeds.example.com/feedName');
你也能用Zend_Feed从一个文件或者一个php字符串变量来获得一个feed的内容:
<?php
// importing a feed from a text file
$feedFromFile = Zend_Feed::importFile('feed.xml');
// importing a feed from a PHP string variable
$feedFromPHP = Zend_Feed::importString($feedString);
在上面的例子中，根据feed类型的不同，一个从Zend_Feed_Abstract继承而来的类对象被返回。如果导入方法获得的是一个RSS feed，那么一个Zend_Feed_Rss对象将被返回(Seateng译注:以Factory模式实现)。另一方面，如果一个Atom feed被导入，那么将返回一个Zend_Feed_Atom对象。如果feed不可读或者不符合规范，导致导入失败那么Zend_Feed将抛出一个Zend_Feed_Exception异常。
15.2.1. 定制 feeds
Zend_Feed 能让开发者轻松创建定制 feeds，只需要创建一个数组用 Zend_Feed 导入它。这个数组可以用 Zend_Feed::importArray() 或 Zend_Feed::importBuilder() 导入。最后数组用定制的实现了 Zend_Feed_Builder_Interface 数据源来处理。
15.2.1.1. 导入定制的数组
<?php
// 从数组导入 feed
$atomFeedFromArray = Zend_Feed::importArray($array);
// 下面一行和上面相同；缺省地 Zend_Feed_Atom 实例被返回
$atomFeedFromArray = Zend_Feed::importArray($array, 'atom');
// 从数组导入 rss feed
$rssFeedFromArray = Zend_Feed::importArray($array, 'rss');
数组格式必须和这个结构一致：
<?php
array(
'title' => 'title of the feed', //required
'link' => 'canonical url to the feed', //required
'lastUpdate' => 'timestamp of the update date', // optional
'published' => 'timestamp of the publication date', //optional
'charset' => 'charset of the textual data', // required
'description' => 'short description of the feed', //optional
'author' => 'author/publisher of the feed', //optional
'email' => 'email of the author', //optional
'webmaster' => 'email address for person responsible for technical issues' // optional, ignored if atom is used
'copyright' => 'copyright notice', //optional
'image' => 'url to image', //optional
'generator' => 'generator', // optional
'language' => 'language the feed is written in', // optional
'ttl' => 'how long in minutes a feed can be cached before refreshing', // optional, ignored if atom is used
'rating' => 'The PICS rating for the channel.', // optional, ignored if atom is used
'cloud' => array(
'DOMain' => 'domain of the cloud, e.g. rpc.sys.com' // required
'port' => 'port to connect to' // optional, default to 80
'path' => 'path of the cloud, e.g. /RPC2' //required
'registerProcedure' => 'procedure to call, e.g. myCloud.rssPleaseNotify' // required
'protocol' => 'protocol to use, e.g. soap or xml-rpc' // required
), // a cloud to be notified of updates // optional, ignored if atom is used
'textInput' => array(
'title' => 'the label of the Submit button in the text input area' // required,
'description' => 'explains the text input area' // required
'name' => 'the name of the text object in the text input area' // required
'link' => 'the URL of the CGI script that processes text input requests' // required
) // a text input box that can be displayed with the feed // optional, ignored if atom is used
'skipHours' => array(
'hour in 24 format', // e.g 13 (1pm)
// up to 24 rows whose value is a number between 0 and 23
) // Hint telling aggregators which hours they can skip // optional, ignored if atom is used
'skipDays ' => array(
'a day to skip', // e.g Monday
// up to 7 rows whose value is a Monday, Tuesday, Wednesday, Thursday, Friday, Saturday or Sunday
) // Hint telling aggregators which days they can skip // optional, ignored if atom is used
'itunes' => array(
'author' => 'Artist column' // optional, default to the main author value
'owner' => array(
'name' => 'name of the owner' // optional, default to main author value
'email' => 'email of the owner' // optional, default to main email value
) // Owner of the podcast // optional
'image' => 'album/podcast art' // optional, default to the main image value
'subtitle' => 'short description' // optional, default to the main description value
'summary' => 'longer description' // optional, default to the main description value
'block' => 'Prevent an episode from appearing (yes|no)' // optional
'category' => array(
array('main' => 'main category', // required
'sub' => 'sub category' // optional
),
// up to 3 rows
) // 'Category column and in iTunes Music Store Browse' // required
'explicit' => 'parental advisory graphic (yes|no|clean)' // optional
'keywords' => 'a comma separated list of 12 keywords maximum' // optional
'new-feed-url' => 'used to inform iTunes of new feed URL location' // optional
) // Itunes extension data // optional, ignored if atom is used
'entries' => array(
array(
'title' => 'title of the feed entry', //required
'link' => 'url to a feed entry', //required
'description' => 'short version of a feed entry', // only text, no html, required
'guid' => 'id of the article, if not given link value will used', //optional
'content' => 'long version', // can contain html, optional
'lastUpdate' => 'timestamp of the publication date', // optional
'comments' => 'comments page of the feed entry', // optional
'commentRss' => 'the feed url of the associated comments', // optional
'source' => array(
'title' => 'title of the original source' // required,
'url' => 'url of the original source' // required
) // original source of the feed entry // optional
'category' => array(
array(
'term' => 'first category label' // required,
'scheme' => 'url that identifies a categorization scheme' // optional
),
array(
//data for the second category and so on
)
) // list of the attached categories // optional
'enclosure' => array(
array(
'url' => 'url of the linked enclosure' // required
'type' => 'mime type of the enclosure' // optional
'length' => 'length of the linked content in octets' // optional
),
array(
//data for the second enclosure and so on
)
) // list of the enclosures of the feed entry // optional
),
array(
//data for the second entry and so on
)
)
);
References:
RSS 2.0 规范： RSS 2.0
Atom 规范：RFC 4287
WFW 规范：Well Formed Web
iTunes 规范： iTunes Technical Specifications
15.2.1.2. 导入定制的数据源
你可以从任何实现 Zend_Feed_Builder_Interface 的数据源创建 Zeed_Feed 实例，只需要实现 getheader() 和 getEntries() 方法来和 Zend_Feed::importBuilder() 一起使用你的对象。作为一个简单的参考实现，你可以使用 Zend_Feed_Builder 它在构造器里带有一个数组，执行一些校验，然后可以在 importBuilder() 方法中使用。getHeader() 方法必须返回 Zend_Feed_Builder_Header 的实例， getEntries() 必须返回 Zend_Feed_Builder_Entry 实例的数组。
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注意 |
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Zend_Feed::importBuilder() 用法的例子：
<?php
// 从定制的 builder 源导入 feed
$atomFeedFromArray = Zend_Feed::importBuilder(new Zend_Feed_Builder($array));
// 和上面一样，缺省地 Zend_Feed_Atom 实例被返回
$atomFeedFromArray = Zend_Feed::importArray(new Zend_Feed_Builder($array), 'atom');
// 从定制的 builder 数组导入 rss feed
$rssFeedFromArray = Zend_Feed::importArray(new Zend_Feed_Builder($array), 'rss');
15.2.1.3. Dumping feed 内容
为了 dump Zend_Feed_Abstract 实例的内容，使用 send() 或 saveXml() 方法。
<?php
assert($feed instanceof Zend_Feed_Abstract);
// dump feed 到标准输出
print $feed->saveXML();
// 发送 http 头和 dump the feed
$feed->send();