README

PHP-Spider Features

supports two traversal algorithms: breadth-first and depth-first
supports crawl depth limiting, queue size limiting and max downloads limiting
supports adding custom URI discovery logic, based on XPath, CSS selectors, or plain old PHP
comes with a useful set of URI filters, such as robots.txt and Domain limiting
supports custom URI filters, both prefetch (URI) and postfetch (Resource content)
supports custom request handling logic
supports Basic, Digest and NTLM HTTP authentication. See example.
comes with a useful set of persistence handlers (memory, file)
supports custom persistence handlers
collects statistics about the crawl for reporting
dispatches useful events, allowing developers to add even more custom behavior
supports a politeness policy

This Spider does not support Javascript.

Installation

The easiest way to install PHP-Spider is with composer. Find it on Packagist.

$ composer require vdb/php-spider

Usage

This is a very simple example. This code can be found in example/example_simple.php. For a more complete example with some logging, caching and filters, see example/example_complex.php. That file contains a more real-world example.

Note that by default, the spider stops processing when it encounters a 4XX or 5XX error responses. To set the spider up to keep processing, please see the link checker example. It uses a custom request handler, that configures the default Guzzle request handler to not fail on 4XX and 5XX responses.

First create the spider

$spider = new Spider('http://www.dmoz.org');

Add a URI discoverer. Without it, the spider does nothing. In this case, we want all <a> nodes from a certain <div>

$spider->getDiscovererSet()->set(new XPathExpressionDiscoverer("//div[@id='catalogs']//a"));

Set some sane options for this example. In this case, we only get the first 10 items from the start page.

$spider->getDiscovererSet()->maxDepth = 1;
$spider->getQueueManager()->maxQueueSize = 10;

Add a listener to collect stats from the Spider and the QueueManager. There are more components that dispatch events you can use.

$statsHandler = new StatsHandler();
$spider->getQueueManager()->getDispatcher()->addSubscriber($statsHandler);
$spider->getDispatcher()->addSubscriber($statsHandler);

Execute the crawl

$spider->crawl();

When crawling is done, we could get some info about the crawl

echo "\n  ENQUEUED:  " . count($statsHandler->getQueued());
echo "\n  SKIPPED:   " . count($statsHandler->getFiltered());
echo "\n  FAILED:    " . count($statsHandler->getFailed());
echo "\n  PERSISTED:    " . count($statsHandler->getPersisted());

Finally we could do some processing on the downloaded resources. In this example, we will echo the title of all resources

echo "\n\nDOWNLOADED RESOURCES: ";
foreach ($spider->getDownloader()->getPersistenceHandler() as $resource) {
    echo "\n - " . $resource->getCrawler()->filterXpath('//title')->text();
}

Contributing

Contributing to PHP-Spider is as easy as Forking the repository on Github and submitting a Pull Request. The Symfony documentation contains an excellent guide for how to do that properly here: Submitting a Patch.

There a few requirements for a Pull Request to be accepted:

Follow the coding standards: PHP-Spider follows the coding standards defined in the PSR-0, PSR-1 and PSR-2 Coding Style Guides;
Prove that the code works with unit tests and that coverage remains 100%;

Note: An easy way to check if your code conforms to PHP-Spider is by running the script bin/static-analysis, which is part of this repo. This will run the following tools, configured for PHP-Spider: PHP CodeSniffer, PHP Mess Detector and PHP Copy/Paste Detector.

Note: To run PHPUnit with coverage, and to check that coverage == 100%, you can run bin/coverage-enforce.

Support

For things like reporting bugs and requesting features it is best to create an issue here on GitHub. It is even better to accompany it with a Pull Request. ;-)

License

PHP-Spider is licensed under the MIT license.

vdb / php-spider

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