Monday, February 14, 2011

ArcGIS Editor for OpenStreetMap

I recently had a chance to test out ArcGIS Editor for OpenStreetMap (1.1 Beta3), an open source toolbox for interacting with OpenStreetMap (OSM). OSM, a popular open-source data repository, gained extra traction in the US after the Haitian Earthquake. This growth came from NGOs, and from some ArcGIS shops with open source leanings, who advocated on behalf of an extension to OSM from ArcGIS. I've been interacting heavily with OSM in building and maintaining the University of Delaware Map (UD Map). The data schema for UD Map is based on the OpenStreetMap schema, and interfaces with OpenStreetMap for data updates and publishing. As the project demanded it, and as a test of the new tools, I used the toolkit to publish some pending campus base layers. Alas, this trial ended disappointingly, leaving only manual editing of the vector layer. Append, which could have been used to join the vector input to the OSM polygon layer, did not work as expected: The OSM changeset was not updated, and therefore could not be uploaded to OSM for processing. The tools still look very useful for doing manual editing of OSM data and adding OSM data as fully editable vector layers in a map ... and of course, as code to be expanded upon ... this story is to be continued :-)

Thursday, February 3, 2011

jquery accordion breaks out of containers on ie7 (ie6?)

fixed this issue by giving css position:relative on parent container further up the tree (in this case was the tabs parent)

Google Spreadsheet Data API

I gave a presentation to the U. of Delaware WebDev group and IT-CS&S (RDMS) on the topic of using data from Google Docs Spreadsheets for consumption in a scripted workflow. I'm using this in the UD Map for automatically incorporate rendering decisions from OCM.

The gist is that you open an https stream with headers for
authorizing, capture an authorization token on the response, open
another stream returning an xml of the table, and parse that. In
addition, you could form the url for the second stream with parameters
that query the column of interest, for example.

Here is the presentation:

Here is some sample code (excuse references to my database/tables):



function do_post_request($url, $data, $optional_headers = null)
{
echo "Begin do_post_request \n";
$params = array('http' => array(
'method' => 'POST',
'content' => $data
));
if ($optional_headers !== null) {
$params['http']['header'] = $optional_headers;
}
$ctx = stream_context_create($params);
$fp = @fopen($url, 'rb', false, $ctx);
if (!$fp) {
throw new Exception("Problem with $url, $php_errormsg");
}
$response = @stream_get_contents($fp);
if ($response === false) {
throw new Exception("Problem reading data from $url, $php_errormsg");
}
return $response;
}

function doFromGoogle(){
echo "Begin doFromGoogle \n";
define("GURL", "https://www.google.com/accounts/ClientLogin");
define("SPREADSHEETREFKEY", "***YOURKEYHERE***");

//creates post to google auth, creates $auth string from google
$dataArr = array();
$dataArr['accountType'] = 'GOOGLE';
$dataArr['Email'] = '***YOUREMAILHERE***';
$dataArr['Passwd'] = '***YOURPASSWORDHERE***';
$dataArr['service'] = 'wise'; //name for spreadsheet data service
$dataArr['source'] = '***YOURSORUCENAMEHERE***'; //this may be optional

$dataStr = http_build_query($dataArr);

$opt_headers = 'application/x-www-form-urlencoded';

$responseStr = do_post_request(GURL, $dataStr, $opt_headers);
$responseArr = explode("\n",$responseStr); //breaking apart request to get auth token
$auth = explode("=", $responseArr[2]);
$auth = $auth[1];

$authStr = 'Authorization: GoogleLogin auth=' . $auth;
$url = 'https://spreadsheets.google.com/feeds/list/' . SPREADSHEETREFKEY . '/1/private/full';


$opts = array(
'http'=>array(
'method'=>"GET",
'header'=>"$authStr"
)
);

$context = stream_context_create($opts);

// ini_set('Authorization', "$authStr");

$handle = fopen($url, "r", false, $context);
$contents = stream_get_contents($handle);
fclose($handle);

$xml = new SimpleXMLElement($contents);

$fullquery = null;


$count = 0;
foreach ($xml->entry as $entry){
$count = $count + 1;
$id = $entry->children('http://schemas.google.com/spreadsheets/2006/extended')->osmid;
$render = $entry->children('http://schemas.google.com/spreadsheets/2006/extended')->dorender;
$label = $entry->children('http://schemas.google.com/spreadsheets/2006/extended')->dolabel;
$labelname = $entry->children('http://schemas.google.com/spreadsheets/2006/extended')->labelname;
$maxzoom = $entry->children('http://schemas.google.com/spreadsheets/2006/extended')->maxzoom;
$minzoom = $entry->children('http://schemas.google.com/spreadsheets/2006/extended')->minzoom;
$labelname = addslashes ($labelname);

//$color = $entry->children('http://schemas.google.com/spreadsheets/2006/extended')->color;

//print "$id, $count \n $render \n $label \n $labelname";
print "$id $maxzoom $minzoom\n";

$query = null;

if($render <> ''){
$query .= "UPDATE master SET dorender = '" . $render . "' where osm_id = $id and dorender <> '" . $render ."';\n";
}
if($label <> ''){
$query .= "UPDATE master SET dolabel = '" . $label . "'where osm_id = $id and dolabel <> '" . $label ."';\n";
}
if($labelname <> ''){
$query .= "UPDATE master SET labelname = '" . $labelname . "'where osm_id = $id and labelname <> '" . $labelname ."';\n\n";
}
if($maxzoom <> ''){
$query .= "UPDATE master SET maxzoom = '" . $maxzoom . "'where osm_id = $id;\n\n";
}
if($minzoom <> ''){
$query .= "UPDATE master SET minzoom = '" . $minzoom . "'where osm_id = $id;\n\n";
}

$fullquery .= $query;
}

//print($query);
$result = pg_query($fullquery) or die('Query failed: ' . pg_last_error());
}