Open-ILS/web/opac/common/js/RemoteRequest.js

   1 var XML_HTTP_GATEWAY = "gateway";
   2 var XML_HTTP_SERVER = "gapines.org";
   3 var XML_HTTP_MAX_TRIES = 3;
   4
   5 var IAMXUL = false;
   6 function isXUL() { return IAMXUL; }
   7
   8 var _allrequests = {};
   9
  10 function cleanRemoteRequests() {
  11         for( var i in _allrequests )
  12                 destroyRequest(_allrequests[i]);
  13 }
  14
  15 function destroyRequest(r) {
  16         if(r == null) return;
  17         r.xmlhttp.onreadystatechange = function(){};
  18         r.xmlhttp                               = null;
  19         r.callback                              = null;
  20         r.userdata                              = null;
  21         _allrequests[r.id]      = null;
  22 }
  23
  24 /* ----------------------------------------------------------------------- */
  25 /* Request object */
  26 function RemoteRequest( service, method ) {
  27
  28
  29         this.service    = service;
  30         this.method             = method;
  31         this.xmlhttp    = false;
  32         this.name               = null;
  33         this.sendCount = 0;
  34
  35         this.type               = "POST"; /* default */
  36         this.id                 = service + method + Math.random();
  37         this.cancelled = false;
  38
  39         _allrequests[this.id] = this;
  40
  41         var i = 2;
  42         this.params = "";
  43
  44         while(i < arguments.length) {
  45                 var object = js2JSON(arguments[i++]);
  46                 this.params += "&param=" + encodeURIComponent(object);
  47         }
  48
  49         if(!this.params) { this.params = ""; }
  50         this.param_string = "service=" + service + "&method=" + method + this.params;
  51         if( this.buildXMLRequest() == null ) alert("Browser is not supported!");
  52 }
  53
  54 /* constructs our XMLHTTPRequest object */
  55 RemoteRequest.prototype.buildXMLRequest = function() {
  56
  57         var x;
  58         try {
  59                 x = new ActiveXObject("Msxml2.XMLHTTP");
  60         } catch (e) {
  61                 try {
  62                         x = new ActiveXObject("Microsoft.XMLHTTP");
  63                 } catch (E) {
  64                         x = false;
  65                 }
  66         }
  67
  68         if (!x && typeof XMLHttpRequest!='undefined') x = new XMLHttpRequest();
  69
  70         if(!x) {
  71                 alert("NEEDS NEWER JAVASCRIPT for XMLHTTPRequest()");
  72                 return null;
  73         }
  74
  75         this.xmlhttp = x;
  76         return true;
  77 }
  78
  79
  80 function _remoteRequestCallback(id) {
  81
  82         var object = _allrequests[id];
  83         if(object.cancelled) return;
  84
  85         if( object.xmlhttp.readyState == 4 ) {
  86                 try {
  87                         object.callback(object);
  88                 } catch(E) {
  89
  90                         /* if we receive a communication error, retry the request up
  91                                 to XML_HTTP_MAX_TRIES attempts */
  92                         if( instanceOf(E, EXCommunication) ) {
  93
  94                                 if(object.sendCount >= XML_HTTP_MAX_TRIES ) {
  95                                         if(isXUL()) throw object;
  96                                          else alert("Arrrgghh, Matey! Error communicating:\n" + E  + "\n" + object.param_string);
  97                                 } else {
  98                                         object.buildXMLRequest();
  99                                         object.send();
 100                                         return;
 101                                 }
 102                         } else { throw E; }
 103
 104                 } finally {
 105                         destroyRequest(object);
 106                         object = null;
 107                 }
 108         }
 109 }
 110
 111
 112 /* define the callback we use when this request has received
 113         all of its data */
 114 RemoteRequest.prototype.setCompleteCallback = function(callback) {
 115         if(this.cancelled) return;
 116         this.callback = callback;
 117         var id = this.id;
 118         this.xmlhttp.onreadystatechange = function() { _remoteRequestCallback(id); }
 119 }
 120
 121
 122 /* http by default.  This makes it https. *ONLY works when
 123         embedded in a XUL app. */
 124 RemoteRequest.prototype.setSecure = function(bool) {
 125         this.secure = bool;
 126 }
 127
 128 RemoteRequest.prototype.send = function(blocking) {
 129
 130         if(this.cancelled) return;
 131
 132         /* determine the xmlhttp server dynamically */
 133         var url = location.protocol + "//" + location.host + "/" + XML_HTTP_GATEWAY;
 134
 135         if(isXUL()) {
 136                 if(this.secure)
 137                         url =   "https://" + XML_HTTP_SERVER + "/" + XML_HTTP_GATEWAY;
 138                 else
 139                         url =   "http://" + XML_HTTP_SERVER + "/" + XML_HTTP_GATEWAY;
 140         }
 141
 142         var data = null;
 143
 144         if( this.type == 'GET' ) {
 145                 url +=  "?" + this.param_string;
 146         }
 147
 148         if(blocking) {
 149                 this.xmlhttp.open(this.type, url, false);
 150         } else {
 151                 this.xmlhttp.open(this.type, url, true);
 152         }
 153
 154
 155         if( this.type == 'POST' ) {
 156                 data = this.param_string;
 157                 this.xmlhttp.setRequestHeader('Content-Type',
 158                                 'application/x-www-form-urlencoded');
 159         }
 160
 161         this.xmlhttp.send( data );
 162         this.sendCount += 1;
 163         return this;
 164 }
 165
 166 /* returns the actual response text from the request */
 167 RemoteRequest.prototype.getText = function() {
 168         return this.xmlhttp.responseText;
 169 }
 170
 171 RemoteRequest.prototype.isReady = function() {
 172         return this.xmlhttp.readyState == 4;
 173 }
 174
 175
 176 /* returns the JSON->js result object  */
 177 RemoteRequest.prototype.getResultObject = function() {
 178         if(this.cancelled) return null;
 179
 180         var text = this.xmlhttp.responseText;
 181         var obj = JSON2js(text);
 182
 183         if(obj == null) return null;
 184         if(obj.is_err)  throw new EXCommunication(obj.err_msg);
 185         if( obj[0] != null && obj[1] == null ) obj = obj[0];
 186
 187         /* these are user level exceptions from the server code */
 188         if(instanceOf(obj, ex)) {
 189                 if(!isXUL()) alert(obj.err_msg());
 190                 throw obj;
 191         }
 192
 193         if(instanceOf(obj, perm_ex)) {
 194                 /* the opac will go ahead and spit out the error msg */
 195                 if(!isXUL()) alert(obj.err_msg());
 196                 throw obj;
 197         }
 198
 199         return obj;
 200 }
 201
 202 /* adds a new parameter to the request */
 203 RemoteRequest.prototype.addParam = function(param) {
 204         var string = encodeURIComponent(js2JSON(param));
 205         this.param_string += "&param=" + string;
 206 }
 207