Question

我必须在一个页面的不同部分显示不同的Feed，同样我有从Feed网址创建的数组，就像

现在我想从上面的数组中选取4个最新的供稿并显示3个供稿。

我该怎么做？

我正在使用PHP ..，

获取数组的代码如下：

class Rss
{
    /* Private variables */
    private $parser;
    private $feed_url;
    private $item;
    private $tag;
    private $output;
    private $counter = 0;

    /* Private variables for RSS */
    private $title = false;
    private $description = false;
    private $link = false;
    private $category = false;
    private $pubDate = false;
    private $image = false;

    /* Setup constants */
    const XML = 'XML'; // for XML parser
    const SXML = 'SXML'; // for SimpleXML parser
    const TXT = 'TXT'; // for text parser using regular expressions

    // {{{ construct
    /**
     * Constructor
     */
    function __construct(  )
    {
    }
    // }}}

    // {{{ getFeed
    /**
     * Get RSS feed from given URL, parse it and return
     * as classic array. You can switch between XML,
     * SimpleXML and text (regex) method of reading.
     *
     * @access      public
     * @param       <string> $url Feed URL
     * @param       <constant> $method Reading method
     */
    public function getFeed($url, $method = self::SXML)
    {
        /* Set counter to zero */
        $this->counter = 0;

        /* Method switch */
        switch($method) {
            case 'TXT': // Rss::TXT
                try {
                    return $this->txtParser($url);
                }
                catch (Exception $e) {
                    throw $e;
                }
                break;
            case 'SXML': // Rss::SXML
                try {
                    return $this->sXmlParser($url);
                }
                catch (Exception $e) {
                    throw $e;
                }
                break;
            default:
            case 'XML': // Rss::XML
                try {
                    return $this->xmlParser($url);
                }
                catch (Exception $e) {
                    throw $e;
                }
                break;
        }
    }
    // }}}

    // {{{ sXmlParser
    /**
     * Parser for the SimpleXML way.
     *
     * @access      private
     * @param       <string> $url Feed URL
     * @return      <array> $feed Array of items
     */
    private function sXmlParser($url)
    {
        /* Call SimpleXML on file */
        $xml = simplexml_load_file($url);

        /* Iterate */
        foreach($xml->channel->item as $item)   {
            $this->output[$this->counter]['title'] = $item->title;
            $this->output[$this->counter]['description'] = $item->description;
            $this->output[$this->counter]['link'] = $item->link;
            $this->output[$this->counter]['category'] = isset($item->category) ? $item->category : false;
            $this->output[$this->counter]['date'] = $item->pubDate;
            $this->counter++;
        }

        /* Return data */
        return $this->output;
    }
    // }}}

    // {{{ xmlParser
    /**
     * Parser for the XML way.
     *
     * @access      private
     * @param       <string> $url Feed URL
     * @return      <array> $feed Array of items
     */
    private function xmlParser($url)
    {
        /* Create XML parser */
        $this->parser = xml_parser_create();

        /* Set options (skip white spaces) */
        xml_parser_set_option($this->parser, XML_OPTION_SKIP_WHITE, 1);

        /* Put $url to internal storage */
        $this->feed_url = $url;

        /* Use parser within our object */
        xml_set_object($this->parser, $this);

        /* Set element handlers */
        xml_set_element_handler($this->parser, "xmlStartElement", "xmlEndElement");

        /* Set data handler */
        xml_set_character_data_handler($this->parser, "xmlCharacterData");

        /* Open feed */
        try {
            $this->xmlOpenFeed();
        }
        catch (Exception $e) {
            throw $e;
        }

        /* Return data */
        return $this->output;
    }
    // }}}

    // {{{ getFile
    /**
     * Retrieve file contents for usage in Rss::XML
     * and Rss::TXT
     *
     * @access      private
     * @param       <string> $url Feed URL
     * @return      <string> $feed File contents
     */
    private function getFile($url)
    {
        /* Initialize variables */
        $feed = false;

        /* Use cURL if possible */
        if (function_exists('curl_init')) {
            $curl = curl_init();
            curl_setopt($curl, CURLOPT_URL, $url);
            curl_setopt($curl, CURLOPT_HEADER, 0);
            curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);
            curl_setopt($curl, CURLOPT_USERAGENT, 'RSS Feed Reader v2.2 (http://www.phpclasses.org/package/3724-PHP-Parse-and-display-items-of-an-RSS-feed.html)');
            $feed = curl_exec($curl);
            curl_close($curl);
        }
        /* Otherwise, try to use file_get_contents() */
        else if (function_exists('file_get_contents')) {
            $feed = file_get_contents($url); // read
        }
        /* And as a last attempt, try to use fopen() */
        else {
            /* Try to open file */
            $fh = fopen($url, 'r');

            /* Iterate */
            while(!feof($fh))   {
                $feed .= fread($fh, 4096); // read
            } // while(!feof($fh))
        }

        /* If we get no results, throw an exception */
        if ($feed === false)
            throw new Exception("I'm sorry but there's simply no way how I can load the feed...");

        /* Return data */
        return $feed;
    }


    // {{{ txtParser
    /**
     * Shortcut for regex parsing with Rss::TXT
     *
     * @access      private
     * @param       <string> $url Feed URL
     * @return      <array> $feed Array of items
     */
    private function txtParser($url)
    {
        /* Retrieve feed content */
        try {
            $feed = $this->getFile($url);
        }
        catch (Exception $e) {
            throw $e;
        }

        /* Parse */
        $this->txtParseFeed($feed);

        /* Return data */
        return $this->output;
    }
    // }}}

    // {{{ xmlOpenFeed
    /**
     * Reads file for usage with Rss::XML
     *
     * @access      private
     * @return      <void>
     */
    private function xmlOpenFeed()
    {
        /* Retrieve feed content */
        try {
            $feed = $this->getFile($this->feed_url);
        }
        catch (Exception $e) {
            throw $e;
        }

        /* Parse */
        xml_parse($this->parser, $feed, true);

        /* Free parser */
        xml_parser_free($this->parser);
    }
    // }}}

    // {{{ xmlStartElement
    /**
     * Item start handler for Rss::XML parser
     *
     * @access      private
     * @param       <object> $parser Parser reference
     * @param       <string> $tag Tag
     * @return      <void>
     */
    private function xmlStartElement($parser, $tag)
    {
        if ($this->item === true)   {
            $this->tag = $tag;
        }
        else if ($tag === "ITEM")   {
            $this->item = true;
        }
    }
    // }}}

    // {{{ xmlCharacterElement
    /**
     * Item content handler for Rss::XML parser
     *
     * @access      private
     * @param       <object> $parser Parser reference
     * @param       <string> $data Content data
     * @return      <void>
     */
    private function xmlCharacterData($parser, $data)
    {
        /* Run only if we're inside an item */
        if ($this->item === TRUE)   {
            /* Read content tags */
            switch ($this->tag) {
                case "TITLE":
                    $this->title .= $data;
                    break;
                case "CATEGORY":
                    $this->category .= $data;
                    break;
                case "DESCRIPTION":
                    $this->description .= $data;
                    break;
                case "LINK":
                    $this->link .= $data;
                    break;
                case "PUBDATE":
                    $this->pubDate .= $data;
                    break;
                case "IMAGE":
                    $this->image .= $data;
                    break;
            }
        }
    }
    // }}}

    // {{{ xmlEndElement
    /**
     * Item end handler
     *
     * @access      private
     * @param       <object> $parser Parser reference
     * @param       <string> $tag Tag
     * @return      <void>
     */
    function xmlEndElement($parser, $tag)
    {
        if ($tag == 'ITEM') {
            $this->output[$this->counter]['title'] = trim($this->title);
            $this->output[$this->counter]['description'] = trim($this->description);
            $this->output[$this->counter]['category'] = isset($this->category) ? trim($this->category) : false;
            $this->output[$this->counter]['link'] = trim($this->link);
            $this->output[$this->counter]['date'] = trim($this->pubDate);
            $this->output[$this->counter]['image'] = trim($this->image);
            $this->counter++;
            $this->title = false;
            $this->description = false;
            $this->category = false;
            $this->link = false;
            $this->pubDate = false;
            $this->image = false;
            $this->item = false;
        }
    }
    // }}}

    // {{{ txtParseFeed
    /**
     * Parse feed using regexp
     *
     * @access      private
     * @param       <string> $feed Feed string
     * @return      <void>
     */
    private function txtParseFeed($feed)
    {
        $feed = preg_replace('!/\*[^*]*\*+([^/][^*]*\*+)*/!', '', $feed);
        $feed = str_replace(array("\r\n", "\r", "\n", "\t", '  ', '    ', '    '), '', $feed);
        preg_match_all('|<item>(.*)</item>|U', $feed, $m);
        foreach($m[1] as $item) {
            preg_match('|<title>(.*)</title>|U', $item, $title);
            preg_match('|<link>(.*)</link>|U', $item, $link);
            preg_match('|<category>(.*)</category>|U', $item, $category);
            preg_match('|<description>(.*)</description>|U', $item, $description);
            preg_match('|<pubDate>(.*)</pubDate>|U', $item, $pubdate);
            preg_match('|<media:text type="html">(.*)</media:text>|U', $item, $image);
            $this->output[$this->counter]['title'] = $title[1];
            $this->output[$this->counter]['description'] = $description[1];
            $this->output[$this->counter]['link'] = $link[1];
            $this->output[$this->counter]['category'] = isset($category[1]) ? $category[1] : false;
            $this->output[$this->counter]['date'] = $pubdate[1];
            $this->output[$this->counter]['image'] = $image[1];
            $this->counter++;
        }
    }
    // }}}

    // {{{ destruct
    /**
     * Destructor
     */
    function __destruct()
    {
    }
    // }}}

}

$Rss = new Rss;

/*
    Text way
*/
try {
    $feed = $Rss->getFeed('http://rssfeeds.webmd.com/rss/rss.aspx?RSSSource=RSS_PUBLIC', Rss::TXT);
    echo '<pre>';
    echo '<pre>';print_r($feed);exit;
    foreach($feed as $item) {
        echo "<b>Title:</b> <a href=\"$item[link]\">$item[title]</a>\n";
        echo "<b>Published:</b> $item[date]\n";
        echo "<b>Category:</b> $item[category]\n";
        echo "\n$item[image]\n";
        echo "\n$item[description]\n";
        echo "<hr/>";
    }
    echo '</pre>';
}
catch (Exception $e) {
    echo $e->getMessage();
}

请帮助我获得我需要的结果......

Answer 1

您可以使用shuffle（）

$numbers = range(0, sizeof($feed_array));
srand((float)microtime() * 1000000);
shuffle($numbers);
for($i=0, $i<2; $i++){
    echo $feed_array($numbers[$i]);
}

Answer 2

我认为RSS源仍然是按日期顺序排列的，因此最新的RSS源是第一个。如果是这样，那么为了获得4个馈送中的随机3个，您可以执行以下操作。

$feeds = //the array
shuffle($feeds);
$first = $feeds[0];
$second = $feeds[1];
$third = $feeds[2];

Answer 3

或者你也可以使用 - array_rand（$ feed_array，2）;

srand((float) microtime() * 10000000);

$rand_keys = array_rand($feed_array, 2);
echo $input[$rand_keys[0]] . "\n";
echo $input[$rand_keys[1]] . "\n";

如何从可用的Feed数据中随机显示2个最新的Feed？

3 个答案: