foreach ($nc as $n) {
$edit->userid = $n->firstChild->nodeValue;
if (!in_array($edit->userid, $result->user_id_list)) {
array_push($result->user_id_list, $edit->userid);
}
}
// name
$nc = $xpath->query("wiki:contributor/wiki:username", $node);
foreach ($nc as $n) {
$edit->username = $n->firstChild->nodeValue;
$result->user_name_list[$edit->userid] = $edit->username;
}
// text
$nc = $xpath->query("wiki:text", $node);
foreach ($nc as $n) {
$edit->text = $n->firstChild->nodeValue;
}
if ($limit == 0 or $revision_count < $limit) {
array_push($result->edits, $edit);
} else {
break;
}
$revision_count++;
}
return $result;
}
// test
if (0) {
$e = xml_edits($xml);
print_r($e);
}
function display_svg($page_title)
{
$user_agent = '*****@*****.**';
// Get XML history of Wikipedia page
$page_title = str_replace(' ', '_', $page_title);
$xml = get('http://en.wikipedia.org/wiki/Special:Export/' . $page_title . '?history', $user_agent);
if ($xml == '') {
//die('Didn\'t get XML');
return false;
}
//echo $xml;
// Extra metadata about each revision of this page
$history = xml_edits($xml);
//print_r($history);
if (count($history->edits) == 0) {
return false;
}
// Texts to compare
$texts = array();
foreach ($history->edits as $e) {
array_push($texts, explode("\n", $e->text));
}
// First revision
$start = new stdclass();
$start->authors = array();
$start->match = array();
$start->id = $history->edits[0]->id;
for ($i = 0; $i < count($texts[0]); $i++) {
$start->authors[$i] = $history->edits[0]->userid;
}
// Get differences between subsequent pairs of revisions
$revisions = array();
$revisions[0] = $start;
$n = count($history->edits);
for ($i = 1; $i < $n; $i++) {
$revision = new stdclass();
$revision->authors = array();
$revision->match = array();
$revision->id = $history->edits[$i]->id;
$revisions[$i] = $revision;
pairwise_diff($texts[$i - 1], $texts[$i], $revisions[$i - 1]->authors, $revisions[$i]->authors, $history->edits[$i]->userid, $revisions[$i - 1]->match);
}
/*
foreach ($revisions as $rev)
{
echo "Authors\n";
print_r($rev->authors);
echo "Match\n";
print_r($rev->match);
}
*/
// Generate SVG
$author_colour = array();
$view_width = 1000;
$view_height = 500;
$x = 10;
$y = 20;
// How many revisions?
$num_rev = count($revisions);
$max_lines = 0;
foreach ($texts as $text) {
$max_lines = max($max_lines, count($text));
}
$x_gap = $view_width / $num_rev;
$x_gap = min(30, $x_gap);
$x_gap = max(1, $x_gap);
$y_gap = $view_height / $max_lines;
$y_gap = min(30, $y_gap);
$y_gap = max(1, $y_gap);
$stroke_width = $x_gap / 2;
$stroke_width = max(1, $stroke_width);
$half_stroke = $stroke_width / 2;
$svg = '<?xml version="1.0" encoding="UTF-8"?>
<svg xmlns:xlink="http://www.w3.org/1999/xlink"
xmlns="http://www.w3.org/2000/svg"
width="' . $view_width . 'px"
height="' . $view_height . 'px"
>';
foreach ($revisions as $rev) {
// Get authors in this revision
$a = array();
foreach ($rev->authors as $k => $v) {
array_push($a, $v);
}
$a = array_unique($a);
// New authors
$n = array_diff($a, array_keys($author_colour));
// Random colour from our range
foreach ($n as $author_id) {
$author_colour[$author_id] = 'rgb(' . rand(0, 255) . ',' . rand(0, 255) . ',' . rand(0, 255) . ')';
}
// Column representing this edit
$svg .= '<a xlink:href="http://en.wikipedia.org/w/index.php?oldid=' . $rev->id . '" title="Revision ' . $rev->id . '" target="_new" >';
foreach ($rev->authors as $k => $v) {
$y_pos = $y + $k * $y_gap;
$svg .= '<path style="stroke:' . $author_colour[$v] . ';stroke-width:' . $stroke_width . ';stroke-linecap:butt;" d="M ' . $x . ' ' . $y_pos . ' ' . $x . ' ' . ($y_pos + $y_gap) . '" />';
}
$svg .= '</a>';
// Draw polygon linking each segement of text in two adjacent revisions
$start_x = $x;
$end_x = $x + $x_gap;
foreach ($rev->match as $k => $v) {
$start_y = $y + $k * $y_gap;
$end_y = $y + $v * $y_gap;
$user_url = '';
if (isset($history->user_name_list[$rev->authors[$k]])) {
$user_url = 'http://en.wikipedia.org/wiki/User:'******'http://en.wikipedia.org/wiki/Special:Contributions/' . $rev->authors[$k];
}
$svg .= '<a xlink:href="' . $user_url . '" title="Revision ' . $rev->id . '" target="_new" >';
$svg .= '<polygon style="fill:' . $author_colour[$rev->authors[$k]] . ';stroke-width:0;opacity:0.4;" points="' . ($start_x + $half_stroke) . ', ' . $start_y . ' ' . ($end_x - $half_stroke) . ', ' . $end_y . ' ' . ($end_x - $half_stroke) . ', ' . ($end_y + $y_gap) . ' ' . ($start_x + $half_stroke) . ', ' . ($start_y + $y_gap) . ' ' . ($start_x + $half_stroke) . ', ' . $start_y . '" />';
$svg .= '</a>';
}
$x += $x_gap;
}
$svg .= '</svg>';
echo '<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>Wikipedia History Flow</title>
<style type="text/css" title="text/css">
body { font-family: sans-serif; }
</style>
</head>
<body>
<h1>Wikipedia History Flow</h1>';
echo '<p>History flow for Wikipedia page <a href="http://en.wikipedia.org/wiki/' . $page_title . '" target="_new">' . $page_title . '</a> (<a href=".">try another</a>)</p>';
echo '<div style="background-color:rgb(128,128,128);">';
echo $svg;
echo '</div>';
echo '<p>Key:</p>
<ul>
<li>Columns represent revisions of the page (click on a colunn to see that revision)</li>
<li>Rows of text that are the same between revisions are connected by lines coloured by author</li>
<li>Authors are distinguished by colour, click on a line between a column to go to that user\'s Wikipedia page</li>
</ul>';
echo '
<body>
</html>';
return true;
}
