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ralgervsphp-spider

MIT 3 1 152
1.2 thousand (month) Dec 22 2019 2.2.4(3 years ago)
1,314 1 4 MIT
v0.7.2(2 months ago) Mar 16 2013 70 (month)

ralger is a small web scraping framework for R based on rvest and xml2.

It's goal to simplify basic web scraping and it provides a convenient and easy to use API.

It offers functions for retrieving pages, parsing HTML using CSS selectors, automatic table parsing and auto link, title, image and paragraph extraction.

php-spider is a PHP library for web crawling and scraping. It allows developers to easily navigate and extract data from websites by simulating a web browser's behavior.

  • 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 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.

Example Use


library("ralger")

url <- "http://www.shanghairanking.com/rankings/arwu/2021"

# retrieve HTML and select elements using CSS selectors:
best_uni <- scrap(link = url, node = "a span", clean = TRUE)
head(best_uni, 5)
#>  [1] "Harvard University"
#>  [2] "Stanford University"
#>  [3] "University of Cambridge"
#>  [4] "Massachusetts Institute of Technology (MIT)"
#>  [5] "University of California, Berkeley"

# ralger can also parse HTML attributes
attributes <- attribute_scrap(
  link = "https://ropensci.org/",
  node = "a", # the a tag
  attr = "class" # getting the class attribute
)

head(attributes, 10) # NA values are a tags without a class attribute
#>  [1] "navbar-brand logo" "nav-link"          NA
#>  [4] NA                  NA                  "nav-link"
#>  [7] NA                  "nav-link"          NA
#> [10] NA
#

# ralger can automatically scrape tables:
data <- table_scrap(link ="https://www.boxofficemojo.com/chart/top_lifetime_gross/?area=XWW")

head(data)
#> # A tibble: 6 × 4
#>    Rank Title                                      `Lifetime Gross`  Year
#>   <int> <chr>                                      <chr>            <int>
#> 1     1 Avatar                                     $2,847,397,339    2009
#> 2     2 Avengers: Endgame                          $2,797,501,328    2019
#> 3     3 Titanic                                    $2,201,647,264    1997
#> 4     4 Star Wars: Episode VII - The Force Awakens $2,069,521,700    2015
#> 5     5 Avengers: Infinity War                     $2,048,359,754    2018
#> 6     6 Spider-Man: No Way Home                    $1,901,216,740    2021
use Example\StatsHandler;
use VDB\Spider\Discoverer\XPathExpressionDiscoverer;
use Symfony\Contracts\EventDispatcher\Event;
use VDB\Spider\Event\SpiderEvents;
use VDB\Spider\Spider;

require_once('example_complex_bootstrap.php');

// Create Spider
$spider = new Spider('http://dmoztools.net');

// Add a URI discoverer. Without it, the spider does nothing. In this case, we want <a> tags 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;

// Let's add something to enable us to stop the script
$spider->getDispatcher()->addListener(
    SpiderEvents::SPIDER_CRAWL_USER_STOPPED,
    function (Event $event) {
        echo "\nCrawl aborted by user.\n";
        exit();
    }
);

// Add a listener to collect stats to the Spider and the QueueMananger.
// There are more components that dispatch events you can use.
$statsHandler = new StatsHandler();
$spider->getQueueManager()->getDispatcher()->addSubscriber($statsHandler);
$spider->getDispatcher()->addSubscriber($statsHandler);

// Execute crawl
$spider->crawl();

// Build a report
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();
}

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