Cannot get data from REST URL

[MtAiryEd]

I thought this would be easy. The United States Geological Survey (USGS) now has a way of getting stream flow data from a REST URL. There are different parameters that can be passed, based on which river gauge is desired, which parameter (ie: water temp, water level), and how many days requested. Below is one such URL:

http://waterservices.usgs.gov/WOF/In...060&period=P1D

If you access this URL directly in a browser, you get XML data. I thought this would be easy to get through some simple Javascript. Here is my code:

var xmlhttp = null;
if (window.XMLHttpRequest) {
  xmlhttp = new XMLHttpRequest();
  if ( typeof xmlhttp.overrideMimeType != 'undefined') {
    xmlhttp.overrideMimeType('text/xml');
  }
} else if (window.ActiveXObject) {
  xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
} else {
  alert('Perhaps your browser does not support xmlhttprequests?');
}
url="http://waterservices.usgs.gov/WOF/InstantaneousValues?location=06306300&variable=00060&period=P1D";
xmlhttp.open('GET', url, false);
xmlhttp.send(null);
xmlhttp.onreadystatechange = function() {
  if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {
    // do something with the results
    alert("4 or 200");
  } else {
    // wait for the call to complete
     alert("NOT 4 or 200");
  }
};

var myObj = eval ( xmlhttp.responseText );

I'm using Firefox/Firebug. I step through the code and see that I'm getting a "301" error. I never saw this before. I looked it up and find that it is:

301 Moved Permanently

The full error in Firebug:

uncaught exception: [Exception... "Component returned failure code: 0x80004005 (NS_ERROR_FAILURE) [nsIXMLHttpRequest.send]" nsresult: "0x80004005 (NS_ERROR_FAILURE)" location: "JS frame :: http://localhost:8080/RiverStatuses/js/index.js :: anonymous :: line 64" data: no]

So, I'm confused.

I also tried dojox's window.name method. That was an adventure. I did what the example told me to do...assigning the call to "deferred". I did get the return XML, but the only way I could see it was to assign it to a DIV. I found no way to assign it to a variable for later processing.

Thanks for any advice/help!

Ed

[MtAiryEd]

Wow, no one?

[Fang]

Try loading to your server first

<?php
$url="http://waterservices.usgs.gov/WOF/InstantaneousValues?location=06306300&variable=00060&period=P1D";
$data = file_get_contents($url);
$file= fopen("myFile.xml", "w");
fwrite($file, $data);
fclose($file);
?>

[MtAiryEd]

Thanks for the reply.

So, I can't do it strictly in Javascript? ..and process the return w/o writing it to a file?

[Fang]

It does appear to be blocked to the open method.