guzzlevsrvest
Guzzle is a PHP HTTP client library that makes it easy to send HTTP requests and trivial to integrate with web services. It allows you to send HTTP/1.1 requests with various methods like GET, POST, PUT, DELETE, and others.
Guzzle also supports sending both synchronous and asynchronous requests, caching, and even has built-in support for OAuth 1.0a. Additionally, it can handle different HTTP errors and handle redirects automatically. It also has built-in support for serializing and deserializing data using formats like JSON and XML, as well as sending multipart file uploads.
Overall Guzzle is an easy to use and powerful library for working with HTTP in PHP.
rvest is a popular R library for web scraping and parsing HTML and XML documents. It is built on top of the xml2 and httr libraries and provides a simple and consistent API for interacting with web pages.
One of the main advantages of using rvest is its simplicity and ease of use. It provides a number of functions that make it easy to extract information from web pages, even for those who are not familiar with web scraping. The html_nodes and html_node functions allow you to select elements from an HTML document using CSS selectors, similar to how you would select elements in JavaScript.
rvest also provides functions for interacting with forms, including html_form, set_values, and submit_form functions. These functions make it easy to navigate through forms and submit data to the server, which can be useful when scraping sites that require authentication or when interacting with dynamic web pages.
rvest also provides functions for parsing XML documents. It includes xml_nodes and xml_node functions, which also use CSS selectors to select elements from an XML document, as well as xml_attrs and xml_attr functions to extract attributes from elements.
Another advantage of rvest is that it provides a way to handle cookies, so you can keep the session alive while scraping a website, and also you can handle redirections with handle_redirects
Example Use
use GuzzleHttp\Client;
// Create a client session:
$client = new Client();
// can also set session details like headers
$client = new Client([
'headers' => [
'User-Agent' => 'webscraping.fyi',
]
]);
// GET request:
$response = $client->get('http://httpbin.org/get');
// print all details
var_dump($response);
// or the important bits
printf("status: %s\n", $response->getStatusCode());
printf("headers: %s\n", json_encode($response->getHeaders(), JSON_PRETTY_PRINT));
printf("body: %s", $response->getBody()->getContents());
// POST request
$response = $client->post(
'https://httpbin.org/post',
// for JSON use json argument:
['json' => ['query' => 'foobar', 'page' => 2]]
// or formdata use form_params:
// ['form_params' => ['query' => 'foobar', 'page' => 2]]
);
// For ASYNC requests getAsync function can be used:
$promise1 = $client->getAsync('https://httpbin.org/get');
$promise2 = $client->getAsync('https://httpbin.org/get?foo=bar');
// await it:
$results = Promise\unwrap([$promise1, $promise2]);
foreach ($results as $result) {
echo $result->getBody();
}
// or add promise callback
Promise\each([$promise1, $promise2], function ($response, $index, $callable) {
echo $response->getBody();
});
library("rvest")
# Rvest can use basic HTTP client to download remote HTML:
tree <- read_html("http://webscraping.fyi/lib/r/rvest")
# or read from string:
tree <- read_html('
<div class="products">
<a href="/product/1">Cat Food</a>
<a href="/product/2">Dog Food</a>
</div>
')
# to parse HTML trees with rvest we use r pipes (the %>% symbol) and html_element function:
# we can use css selectors:
print(tree %>% html_element(".products>a") %>% html_text())
# "[1] "\nCat Food\nDog Food\n""
# or XPath:
print(tree %>% html_element(xpath="//div[@class='products']/a") %>% html_text())
# "[1] "\nCat Food\nDog Food\n""
# Additionally rvest offers many quality of life functions:
# html_text2 - removes trailing and leading spaces and joins values
print(tree %>% html_element("div") %>% html_text2())
# "[1] "Cat Food Dog Food""
# html_attr - selects element's attribute:
print(tree %>% html_element("div") %>% html_attr('class'))
# "products"