[OpenLayers-Users] more headaches with the twitter api

[Nicholas Efremov-Kendall]

Hi all,

I'm still trying to crack this nut, and to do so, I decided to strip out the
need for any transformations, assuming that since both the w3c geoloc and
twitter api's both use epsg 4326 natively. The geolocation works fine,
without any issues, but the tweets still aren't being plotted in the correct
place and I don't really know why. I've got an alert set on the point that's
created, and from what I can tell it is being fed valid coordinates, the
alert returns the following POINT(38.6315 -90.3462). I've plotted the coords
by hand, and can verify that they're coming from the right area What I have
noticed is that the coordinates seem to served as lat-long, rather than
lon-lat (i.e. tweet.geo.coord[0] = lat), but reversing the coordinates
doesn't result in markers getting added to the map, although the coords are
returned in the right order.

Now, as near as I can tell, this problem has to be with the coordinates
being passed to my script from the twitter api itself. Maybe this has to do
with the coords getting passed to me in the wrong data type, but at this
point I'm stumped.

full code is below


var tweetz = new OpenLayers.Layer.Vector("Tweets", {styleMap: new
OpenLayers.StyleMap({externalGraphic:
"OpenLayers-2.11-rc1/img/marker-green.png", pointRadius: 10})});
var marker = new OpenLayers.Layer.Vector("Marker", {styleMap: new
OpenLayers.StyleMap({externalGraphic: "OpenLayers-2.11-rc1/img/marker.png",
pointRadius: 10})});
var map = new OpenLayers.Map('map');
var tweets = [];
var tweetsQ = [];
var refreshQuery = '?=';
function initGIS(){
map.addControl(new OpenLayers.Control.LayerSwitcher());var wms = new
OpenLayers.Layer.WMS(
  "OpenLayers WMS",
  "http://vmap0.tiles.osgeo.org/wms/vmap0",
  {'layers':'basic'} );
map.addLayer(wms);
map.addLayer(tweetz);
map.setCenter(new OpenLayers.LonLat(-90, 38),12);
$(document).everyTime('30s', acquireTweets);
$(document).everyTime('100ms', parseTweetsQ);
getLoc();
}

function getLoc(){if (Modernizr.geolocation) {
navigator.geolocation.getCurrentPosition(plotLoc,handle_error);} else
{yqlgeo.get('visitor',norm_yql_resp);}}

function createTWTsrcURL (){
var temp = map.getCenter();
return 'http://search.twitter.com/search.json' + refreshQuery + '&geocode='
+ temp.lat +'%2C' + temp.lon + '%2C50km&rpp=100&callback=?';
}

function plotLoc (position){
map.addLayer(marker);
var feat = new OpenLayers.Feature.Vector(new
OpenLayers.Geometry.Point(position.coords.longitude,position.coords.latitude));
marker.addFeatures([feat]);
var bounds = marker.getDataExtent();
map.zoomToExtent(bounds);
acquireTweets();
}

function acquireTweets(){
$.getJSON(createTWTsrcURL(), function(data){
if(data.results)
$.each(data.results, function(i, tweet){
if (tweet.geo || tweet.location)
tweetsQ.push(tweet);
});
refreshQuery = data.refresh_url;
});}

function parseTweetsQ(){
if (tweetsQ.length > 0) {
var tweet = tweetsQ.pop();
if (tweet.geo){
tweet.point = new
OpenLayers.Geometry.Point(tweet.geo.coordinates[0],tweet.geo.coordinates[1]);
tweet.attributes = {};
plotTwt(tweet);}}}

function plotTwt(tweet){
alert(tweet.point);
var twtfeat = new OpenLayers.Feature.Vector(tweet.point);
tweetz.addFeatures([twtfeat]);
}
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