/*

Cross-Browser XMLHttpRequest v1.2

=================================

Emulate Gecko 'XMLHttpRequest()' functionality in IE and Opera. Opera requires

the Sun Java Runtime Environment <http://www.java.com/>.

by Andrew Gregory

http://www.scss.com.au/family/andrew/webdesign/xmlhttprequest/

This work is licensed under the Creative Commons Attribution License. To view a

copy of this license, visit http://creativecommons.org/licenses/by-sa/2.5/ or

send a letter to Creative Commons, 559 Nathan Abbott Way, Stanford, California

94305, USA.

Attribution: Leave my name and web address in this script intact.

Not Supported in Opera

----------------------

* user/password authentication

* responseXML data member

Not Fully Supported in Opera

----------------------------

* async requests

* abort()

* getAllResponseHeaders(), getAllResponseHeader(header)

*/

// IE support

if (window.ActiveXObject && !window.XMLHttpRequest) {

  window.XMLHttpRequest = function() {

    var msxmls = new Array(

      'Msxml2.XMLHTTP.5.0',

      'Msxml2.XMLHTTP.4.0',

      'Msxml2.XMLHTTP.3.0',

      'Msxml2.XMLHTTP',

      'Microsoft.XMLHTTP');

    for (var i = 0; i < msxmls.length; i++) {

      try {

        return new ActiveXObject(msxmls[i]);

      } catch (e) {

      }

    }

    return null;

  };

}

// Gecko support

/* ;-) */

// Opera support

if (window.opera && !window.XMLHttpRequest) {

  window.XMLHttpRequest = function() {

    this.readyState = 0; // 0=uninitialized,1=loading,2=loaded,3=interactive,4=complete

    this.status = 0; // HTTP status codes

    this.statusText = '';

    this._headers = [];

    this._aborted = false;

    this._async = true;

    this._defaultCharset = 'ISO-8859-1';

    this._getCharset = function() {

      var charset = _defaultCharset;

      var contentType = this.getResponseHeader('Content-type').toUpperCase();

      val = contentType.indexOf('CHARSET=');

      if (val != -1) {

        charset = contentType.substring(val);

      }

      val = charset.indexOf(';');

      if (val != -1) {

        charset = charset.substring(0, val);

      }

      val = charset.indexOf(',');

      if (val != -1) {

        charset = charset.substring(0, val);

      }

      return charset;

    };

    this.abort = function() {

      this._aborted = true;

    };

    this.getAllResponseHeaders = function() {

      return this.getAllResponseHeader('*');

    };

    this.getAllResponseHeader = function(header) {

      var ret = '';

      for (var i = 0; i < this._headers.length; i++) {

        if (header == '*' || this._headers[i].h == header) {

          ret += this._headers[i].h + ': ' + this._headers[i].v + '\n';

        }

      }

      return ret;

    };

    this.getResponseHeader = function(header) {

      var ret = getAllResponseHeader(header);

      var i = ret.indexOf('\n');

      if (i != -1) {

        ret = ret.substring(0, i);

      }

      return ret;

    };

    this.setRequestHeader = function(header, value) {

      this._headers[this._headers.length] = {h:header, v:value};

    };

    this.open = function(method, url, async, user, password) {

      this.method = method;

      this.url = url;

      this._async = true;

      this._aborted = false;

      this._headers = [];

      if (arguments.length >= 3) {

        this._async = async;

      }

      if (arguments.length > 3) {

        opera.postError('XMLHttpRequest.open() - user/password not supported');

      }

      this.readyState = 1;

      if (this.onreadystatechange) {

        this.onreadystatechange();

      }

    };

    this.send = function(data) {

      if (!navigator.javaEnabled()) {

        alert("XMLHttpRequest.send() - Java must be installed and enabled.");

        return;

      }

      if (this._async) {

        setTimeout(this._sendasync, 0, this, data);

        // this is not really asynchronous and won't execute until the current

        // execution context ends

      } else {

        this._sendsync(data);

      }

    }

    this._sendasync = function(req, data) {

      if (!req._aborted) {

        req._sendsync(data);

      }

    };

    this._sendsync = function(data) {

      this.readyState = 2;

      if (this.onreadystatechange) {

        this.onreadystatechange();

      }

      // open connection

      var url = new java.net.URL(new java.net.URL(window.location.href), this.url);

      var conn = url.openConnection();

      for (var i = 0; i < this._headers.length; i++) {

        conn.setRequestProperty(this._headers[i].h, this._headers[i].v);

      }

      this._headers = [];

      if (this.method == 'POST') {

        // POST data

        conn.setDoOutput(true);

        var wr = new java.io.OutputStreamWriter(conn.getOutputStream(), this._getCharset());

        wr.write(data);

        wr.flush();

        wr.close();

      }

      // read response headers

      // NOTE: the getHeaderField() methods always return nulls for me :(

      var gotContentEncoding = false;

      var gotContentLength = false;

      var gotContentType = false;

      var gotDate = false;

      var gotExpiration = false;

      var gotLastModified = false;

      for (var i = 0; ; i++) {

        var hdrName = conn.getHeaderFieldKey(i);

        var hdrValue = conn.getHeaderField(i);

        if (hdrName == null && hdrValue == null) {

          break;

        }

        if (hdrName != null) {

          this._headers[this._headers.length] = {h:hdrName, v:hdrValue};

          switch (hdrName.toLowerCase()) {

            case 'content-encoding': gotContentEncoding = true; break;

            case 'content-length'  : gotContentLength   = true; break;

            case 'content-type'    : gotContentType     = true; break;

            case 'date'            : gotDate            = true; break;

            case 'expires'         : gotExpiration      = true; break;

            case 'last-modified'   : gotLastModified    = true; break;

          }

        }

      }

      // try to fill in any missing header information

      var val;

      val = conn.getContentEncoding();

      if (val != null && !gotContentEncoding) this._headers[this._headers.length] = {h:'Content-encoding', v:val};

      val = conn.getContentLength();

      if (val != -1 && !gotContentLength) this._headers[this._headers.length] = {h:'Content-length', v:val};

      val = conn.getContentType();

      if (val != null && !gotContentType) this._headers[this._headers.length] = {h:'Content-type', v:val};

      val = conn.getDate();

      if (val != 0 && !gotDate) this._headers[this._headers.length] = {h:'Date', v:(new Date(val)).toUTCString()};

      val = conn.getExpiration();

      if (val != 0 && !gotExpiration) this._headers[this._headers.length] = {h:'Expires', v:(new Date(val)).toUTCString()};

      val = conn.getLastModified();

      if (val != 0 && !gotLastModified) this._headers[this._headers.length] = {h:'Last-modified', v:(new Date(val)).toUTCString()};

      // read response data

      var reqdata = '';

      var stream = conn.getInputStream();

      if (stream) {

        var reader = new java.io.BufferedReader(new java.io.InputStreamReader(stream, this._getCharset()));

        var line;

        while ((line = reader.readLine()) != null) {

          if (this.readyState == 2) {

            this.readyState = 3;

            if (this.onreadystatechange) {

              this.onreadystatechange();

            }

          }

          reqdata += line + '\n';

        }

        reader.close();

        this.status = 200;

        this.statusText = 'OK';

        this.responseText = reqdata;

        this.readyState = 4;

        if (this.onreadystatechange) {

          this.onreadystatechange();

        }

        if (this.onload) {

          this.onload();

        }

      } else {

        // error

        this.status = 404;

        this.statusText = 'Not Found';

        this.responseText = '';

        this.readyState = 4;

        if (this.onreadystatechange) {

          this.onreadystatechange();

        }

        if (this.onerror) {

          this.onerror();

        }

      }

    };

  };

}

// ActiveXObject emulation

if (!window.ActiveXObject && window.XMLHttpRequest) {

  window.ActiveXObject = function(type) {

    switch (type.toLowerCase()) {

      case 'microsoft.xmlhttp':

      case 'msxml2.xmlhttp':

      case 'msxml2.xmlhttp.3.0':

      case 'msxml2.xmlhttp.4.0':

      case 'msxml2.xmlhttp.5.0':

        return new XMLHttpRequest();

    }

    return null;

  };

}