<?php
/////////////////////////////////////////////////
// Term Extraction example from FiveFilters.org
// See http://fivefilters.org/term-extraction/
/////////////////////////////////////////////////

// Text to extract terms from
// --------------------------
$text = 'Inevitably, then, corporations do not restrict themselves merely to the arena of economics. Rather, as John Dewey observed, "politics is the shadow cast on society by big business". Over decades, corporations have worked together to ensure that the choices offered by \'representative democracy\' all represent their greed for maximised profits.

This is a sensitive task. We do not live in a totalitarian society - the public potentially has enormous power to interfere. The goal, then, is to persuade the public that corporate-sponsored political choice is meaningful, that it makes a difference. The task of politicians at all points of the supposed \'spectrum\' is to appear passionately principled while participating in what is essentially a charade.';

// Base URL (where term extractor is installed)
// --------------------------------------------
// $base_url = 'http://example.org/term-extractor/';

$_host = $_SERVER['HTTP_HOST'];
$_path = rtrim(dirname(dirname($_SERVER['SCRIPT_NAME'])), '/\\');
$base_url = 'http://'.htmlspecialchars($_host.$_path).'/';

// Request URL and output mode
// ---------------------------
// Regular output mode
$service_url = $base_url.'extract.php';
// Yahoo output mode
//$service_url .= $base_url.'yahoo.php';

// Request parameters
// ------------------
// The parameters to pass to the web service.
//
// Valid parameters are:
// * text - the text to extract terms from
// * output - the format to return the terms (can be json, txt, xml, php, html)
// * terms_only - set this to 1 if you're only interested in the terms (not the occurrence and term word count)
// * lowercase - set this to 1 to have all extracted terms converted to lowercase
// * callback - for JSONP: name of your Javascript function to receive the JSON response. If JSON has not been requested, this has no effect
// * url - if Full-Text RSS is installed, this can be used instead of 'text', to point to a web article
// * text_or_url - for convenience, this parameter can be used instead of the text or url parameters to accept either a URL (on its own) or some text.
// * key - if you've set one up in config.php, otherwise not required
// * yahoo - set this to 1 to enable Yahoo mode (output format matching that used by Yahoo's Term Extraction service)
// For filtering the results:
// * min_occurrence - the minimum number of times a single-word term must appear for it be included in the output (default 1)
// * max_strength - strength is the number of words in the term, so to reduce results to terms with a maximum of 2 words, set this to 2 (default 3)
// * keep_if_strength - keep a term if the term's word count is equal to or greater than this, regardless of occurrence (default 2)
// * exc[] - check terms for this string, and exclude term if there's a match (partial match counts too), this can appear multiple times.
// * filter - set this to 0 to disable filtering (overriding the four parameters above) (default 1)
// * max - the maximum number of terms to return
//
// For compatibility with Yahoo Term Extraction, we also accept the following parameters:
// * context - same as 'text'
// * appid - same as 'key'
//
// Required parameters: either 'text' or 'url'.
//
// We're going to send this as a HTTP POST request, but it can also be
// sent as a GET request, e.g. 
// http://example.org/te/extract.php?text=text+to+extract+terms+from

$postdata = http_build_query(array(
    'text'     => $text
   ,'output'   => 'json'
));
$opts = array('http' => array(
    'method'  => 'POST',
    'header'  => 'Content-type: application/x-www-form-urlencoded',
    'content' => $postdata
));
$context = stream_context_create($opts);

// Send HTTP request and get response
$result = @file_get_contents($service_url, false, $context);

// Print results
header('Content-Type: text/plain; charset=UTF-8');
echo $result;

/*
// Process results (JSON, regular mode)
if ($result) {
    if ($json = @json_decode($result)) {
        foreach ($json as $term) {
            echo $term[0],"\n";
        }
    }
}
*/