grabber.markdown

Web scraper

The web scraper is useful for feeds that display only a summary of articles, the scraper can download and parse the full content from the original website.

How the content grabber works?

1. Try with rules first (XPath queries) for the domain name (see PicoFeed\Rules\)
2. Try to find the text content by using common attributes for class and id
3. Finally, if nothing is found, the feed content is displayed

The best results are obtained with XPath rules file.

Standalone usage

<?php

use PicoFeed\Client\Grabber;

$grabber = new Grabber($item_url);
$grabber->download();
$grabber->parse();

// Get raw HTML content
echo $grabber->getRawContent();

// Get relevant content
echo $grabber->getContent();

// Get filtered relevant content
echo $grabber->getFilteredContent();

Fetch full item contents during feed parsing

Before parsing all items, just call the method $parser->enableContentGrabber():

<?php

use PicoFeed\Reader\Reader;
use PicoFeed\PicoFeedException;

try {

    $reader = new Reader;

    // Return a resource
    $resource = $reader->download('http://www.egscomics.com/rss.php');

    // Return the right parser instance according to the feed format
    $parser = $reader->getParser(
        $resource->getUrl(),
        $resource->getContent(),
        $resource->getEncoding()
    );

    // Enable content grabber before parsing items
    $parser->enableContentGrabber();

    // Return a Feed object
    $feed = $parser->execute();
}
catch (PicoFeedException $e) {
    // Do Something...
}

When the content scraper is enabled, everything will be slower. For each item a new HTTP request is made and the HTML downloaded is parsed with XML/XPath.

Configuration

Enable content grabber for items

• Method name: enableContentGrabber()
• Default value: false (content grabber is disabled by default)
• Argument value: none

$parser->enableContentGrabber();

Ignore item urls for the content grabber

• Method name: setGrabberIgnoreUrls()
• Default value: empty (fetch all item urls)
• Argument value: array (list of item urls to ignore)

$parser->setGrabberIgnoreUrls(['http://foo', 'http://bar']);

How to write a grabber rules file?

Add a PHP file to the directory PicoFeed\Rules, the filename must be the same as the domain name:

Example with the BBC website, www.bbc.co.uk.php:

<?php
return array(
    'test_url' => 'http://www.bbc.co.uk/news/world-middle-east-23911833',
    'body' => array(
        '//div[@class="story-body"]',
    ),
    'strip' => array(
        '//script',
        '//form',
        '//style',
        '//*[@class="story-date"]',
        '//*[@class="story-header"]',
        '//*[@class="story-related"]',
        '//*[contains(@class, "byline")]',
        '//*[contains(@class, "story-feature")]',
        '//*[@id="video-carousel-container"]',
        '//*[@id="also-related-links"]',
        '//*[contains(@class, "share") or contains(@class, "hidden") or contains(@class, "hyper")]',
    )
);

Actually, only body, strip and test_url are supported.

Don't forget to send a pull request or a ticket to share your contribution with everybody,

List of content grabber rules

Rules are stored inside the directory lib/PicoFeed/Rules