//
//  jsrsClient.js - javascript remote scripting client include
//  
//  Author:  Brent Ashley [jsrs@megahuge.com]
//
//  make asynchronous remote calls to server without client page refresh
//
//  see license.txt for copyright and license information

/*
see history.txt for full history
2.0  26 Jul 2001 - added POST capability for IE/MOZ
*/

// callback pool needs global scope
var jsrsContextPoolSize = 0;
var jsrsContextMaxPool = 100;
var jsrsContextPool = new Array();
var jsrsBrowser = jsrsBrowserSniff();

// constructor for context object
function jsrsContextObj( contextID ){
  
  // properties
  this.id = contextID;
  this.busy = true;
  this.callback = null;
  this.container = contextCreateContainer( contextID );
  
  // methods
  this.GET = contextGET;
  this.getPayload = contextGetPayload;
  this.setVisibility = contextSetVisibility;
}

//  method functions are not privately scoped 
//  because Netscape's debugger chokes on private functions
function contextCreateContainer( containerName ){
  // creates hidden container to receive server data 
  var container;
  switch( jsrsBrowser ) {
    case 'NS':
      container = new Layer(100);
      container.name = containerName;
      container.visibility = 'hidden';
      container.clip.width = 100;
      container.clip.height = 100;
      break;
    
    case 'IE':
      document.body.insertAdjacentHTML( "afterBegin", '<span id="SPAN' + containerName + '"></span>' );
      var span = document.all( "SPAN" + containerName );
      var html = '<iframe name="' + containerName + '" src=""></iframe>';
      span.innerHTML = html;
      span.style.display = 'none';
      container = window.frames[ containerName ];
      break;
      
    case 'MOZ':  
      var span = document.createElement('SPAN');
      span.id = "SPAN" + containerName;
      document.body.appendChild( span );
      var iframe = document.createElement('IFRAME');
      iframe.name = containerName;
      span.appendChild( iframe );
      container = iframe;
      break;
  }
  return container;
}


function contextGET( rsPage ){

  // build URL to call
  var URL = rsPage;

  // always send context
  if (URL.indexOf("?") != -1)
    URL += "&";
  else
    URL += "?";
  URL += "C=" + this.id;

  // unique string to defeat cache
  var d = new Date();
  URL += "&U=" + d.getTime();

  // make the call
  switch( jsrsBrowser ) {
    case 'NS':
      this.container.src = URL;
      break;
    case 'IE':
      this.container.document.location.replace(URL);
      break;
    case 'MOZ':
      this.container.src = '';
      this.container.src = URL; 
      break;
  }  
  
}

function contextGetPayload(){
  switch( jsrsBrowser ) {
    case 'NS':
      return this.container.document.forms['jsrs_Form'].elements['jsrs_Payload'].value;
    case 'IE':
      return this.container.document.forms['jsrs_Form']['jsrs_Payload'].value;
    case 'MOZ':
      return window.frames[this.container.name].document.forms['jsrs_Form']['jsrs_Payload'].value; 
  }  
}

function contextSetVisibility( vis ){
  switch( jsrsBrowser ) {
    case 'NS':
      this.container.visibility = (vis)? 'show' : 'hidden';
      break;
    case 'IE':
      document.all("SPAN" + this.id ).style.display = (vis)? '' : 'none';
      break;
    case 'MOZ':
      document.getElementById("SPAN" + this.id).style.visibility = (vis)? '' : 'hidden';
      this.container.width = (vis)? 250 : 0;
      this.container.height = (vis)? 100 : 0;
      break;
  }  
}

// end of context constructor

function jsrsGetContextID(){
  var contextObj;
  for (var i = 1; i <= jsrsContextPoolSize; i++){
    contextObj = jsrsContextPool[ 'jsrs' + i ];
    if ( !contextObj.busy ){
      contextObj.busy = true;      
      return contextObj.id;
    }
  }
  // if we got here, there are no existing free contexts
  if ( jsrsContextPoolSize <= jsrsContextMaxPool ){
    // create new context
    var contextID = "jsrs" + (jsrsContextPoolSize + 1);
    jsrsContextPool[ contextID ] = new jsrsContextObj( contextID );
    jsrsContextPoolSize++;
    return contextID;
  } else {
    //alert( "jsrs Error:  context pool full" );
    return null;
  }
}

function jsrsExecute( rspage, callback ){
  // call a server routine from client code
  //
  // rspage      - href to asp file
  // callback    - function to call on return 
  //               or null if no return needed
  //               (passes returned string to callback)

  // get context
  var contextObj = jsrsContextPool[ jsrsGetContextID() ];
  contextObj.callback = callback;

  contextObj.setVisibility( false );
  contextObj.GET( rspage );

  return contextObj.id;
}

function jsrsLoaded( contextID ){
  // get context object and invoke callback
  var contextObj = jsrsContextPool[ contextID ];
  if (contextObj != null) {
      if(contextObj.callback != null) {
        contextObj.callback( jsrsUnescape( contextObj.getPayload() ) );
      }
      // clean up and return context to pool
      contextObj.callback = null;
      contextObj.busy = false;
  }
}

function jsrsError( contextID, str ){
  alert( unescape(str) );
  jsrsContextPool[ contextID ].busy = false
}

function jsrsEscapeQQ( thing ){
  return thing.replace(/'"'/g, '\\"');
}

function jsrsUnescape( str ){
  // payload has slashes escaped with whacks
  return str.replace( /\\\//g, "/" );
}

function jsrsBrowserSniff(){
  if (document.layers) return "NS";
  if (document.all) return "IE";
  if (document.getElementById) return "MOZ";
  return "OTHER";
}

/////////////////////////////////////////////////
//
// user functions

function jsrsArrayFromString( s, delim ){
  // rebuild an array returned from server as string
  // optional delimiter defaults to ~
  var d = (delim == null)? '~' : delim;
  return s.split(d);
}

function jsrsDebugInfo(){
  // use for debugging by attaching to f1 (works with IE)
  // with onHelp = "return jsrsDebugInfo();" in the body tag
  var doc = window.open().document;
  doc.open;
  doc.write( 'Pool Size: ' + jsrsContextPoolSize + '<br><font face="arial" size="2"><b>' );
  for( var i in jsrsContextPool ){
    var contextObj = jsrsContextPool[i];
    doc.write( '<hr>' + contextObj.id + ' : ' + (contextObj.busy ? 'busy' : 'available') + '<br>');
    doc.write( contextObj.container.document.location.pathname + '<br>');
    doc.write( contextObj.container.document.location.search + '<br>');
    doc.write( '<table border="1"><tr><td>' + contextObj.container.document.body.innerHTML + '</td></tr></table>' );
  }
  doc.write('</table>');
  doc.close();
  return false;
}