Parse XML in PHP

http://php.net/manual/en/function.file-get-contents.php - fetch URL
http://php.net/manual/en/simplexmlelement.xpath.php - parse XML
http://www.php.net/manual/en/simplexml.examples-basic.php - register namespaces, etc.

Example for Google calendar. Most important parts are the namespaces and (string) casting.

    $contents = file_get_contents($calendar_url); // should end with 'full', not 'basic'
    $xml = new SimpleXMLElement($contents);

    $namespaces = $xml->getDocNamespaces();
    $xml->registerXPathNamespace('__empty_ns', $namespaces['']);
    $xml->registerXPathNamespace('gd', 'http://schemas.google.com/g/2005'); # xmlns:gd='http://schemas.google.com/g/2005'

    $entries = $xml->xpath("//__empty_ns:entry");
    while(list( , $node) = each($entries)) {
        $time_nodes = $node->xpath("gd:when/@startTime");
        while ($time_node = each($time_nodes)) {
            # <gd:when endTime="2011-08-19T17:00:00.000+01:00" startTime="2011-08-19T14:00:00.000+01:00"></gd:when>

            $time_text = (string)$time_node[1]->startTime;

            die "time = $time_text\n";

Parse HTML with Ruby and Nokogiri

doc = Nokogiri::HTML(open(filename, 'r'))
puts doc.xpath('//title')[0].inner_html
puts doc.xpath('//h2')

URI encoding in Java

Deprecated Apache Commons HttpClient 3.x:

 

import org.apache.commons.httpclient.URIException;

import org.apache.commons.httpclient.util.URIUtil;

String uriTest1(String uri) {

    String encodedUri = null;

    try {

        encodedUri = URIUtil.encodePath(uri,"UTF-8");

    } catch (URIException e) {

        System.err.println("Caught URI Exception");

        e.printStackTrace();

    }

    return encodedUri;

}

URIEncoder encodes to application/x-www-form-urlencoded (i.e. spaces turn to +)

import java.io.UnsupportedEncodingException;
import java.net.URISyntaxException;
import java.net.URLEncoder;

String uriTest2(String uri) {
    String encodedUri = null;
    String encoding = "UTF-8";
    try {
        encodedUri = URLEncoder.encode(uri, encoding);
    } catch (UnsupportedEncodingException e) {
        System.err.println("Unsuported encoding: "+encoding);
        e.printStackTrace();
    }
    return encodedUri;
}

java.net.URI requires the whole URI to be input, but you can extract just the URI encoded query part (turns spaces to %20)

import java.net.URI;

private static String uriTest3(String path) {
    String encodedUri = null;
    URI uri = null;
    try {
        uri = new URI("http","bbc.co.uk","/search/news/",path,null);
    } catch (URISyntaxException e) {
        System.err.println("Caught URI Syntax Exception");
        e.printStackTrace();
    }
    encodedUri = uri.getRawQuery();
    return encodedUri;
}
See also.

Beware of backslashes in login strings

using URI to parse an ftp connection string like:

ftp://domain\user:pass@host/path

...can lead to problems.
The backslash is not a legal URI character, so $uri->user may bring back just the domain!