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() { try { if(IAMXUL) return true;}catch(e){return false;}; }
   7
   8 /* some communication exceptions */
   9 function EX(message) { this.init(message); }
  10 EX.prototype.init = function(message) { this.message = message; }
  11 EX.prototype.toString = function() { return "\n *** Exception Occured \n" + this.message; }
  12 EXCommunication.prototype              = new EX();
  13 EXCommunication.prototype.constructor  = EXCommunication;
  14 EXCommunication.baseClass              = EX.prototype.constructor;
  15 function EXCommunication(message) { this.classname="EXCommunication"; this.init("EXCommunication: " + message); }
  16 /* ------------------------------------------------ */
  17
  18
  19 var _allrequests = {};
  20
  21 function cleanRemoteRequests() {
  22         for( var i in _allrequests )
  23                 destroyRequest(_allrequests[i]);
  24 }
  25
  26 function destroyRequest(r) {
  27         if(r == null) return;
  28         r.xmlhttp.onreadystatechange = function(){};
  29         r.xmlhttp                               = null;
  30         r.callback                              = null;
  31         r.userdata                              = null;
  32         _allrequests[r.id]      = null;
  33 }
  34
  35 /* ----------------------------------------------------------------------- */
  36 /* Request object */
  37 function RemoteRequest( service, method ) {
  38
  39
  40         this.service    = service;
  41         this.method             = method;
  42         this.xmlhttp    = false;
  43         this.name               = null;
  44         this.sendCount = 0;
  45
  46         this.type               = "POST"; /* default */
  47         this.id                 = service + method + Math.random();
  48         this.cancelled = false;
  49
  50         _allrequests[this.id] = this;
  51
  52         var i = 2;
  53         this.params = "";
  54
  55         while(i < arguments.length) {
  56                 var object = js2JSON(arguments[i++]);
  57                 this.params += "&param=" + encodeURIComponent(object);
  58         }
  59
  60         if(!this.params) { this.params = ""; }
  61         this.param_string = "service=" + service + "&method=" + method + this.params;
  62         if( this.buildXMLRequest() == null ) alert("Browser is not supported!");
  63 }
  64
  65 /* constructs our XMLHTTPRequest object */
  66 RemoteRequest.prototype.buildXMLRequest = function() {
  67
  68         var x;
  69         try {
  70                 x = new ActiveXObject("Msxml2.XMLHTTP");
  71         } catch (e) {
  72                 try {
  73                         x = new ActiveXObject("Microsoft.XMLHTTP");
  74                 } catch (E) {
  75                         x = false;
  76                 }
  77         }
  78
  79         if (!x && typeof XMLHttpRequest!='undefined') x = new XMLHttpRequest();
  80
  81         if(!x) {
  82                 alert("NEEDS NEWER JAVASCRIPT for XMLHTTPRequest()");
  83                 return null;
  84         }
  85
  86         this.xmlhttp = x;
  87         return true;
  88 }
  89
  90
  91 function _remoteRequestCallback(id) {
  92
  93         var object = _allrequests[id];
  94         if(object.cancelled) return;
  95
  96         if( object.xmlhttp.readyState == 4 ) {
  97                 try {
  98                         object.callback(object);
  99                 } catch(E) {
 100
 101                         /* if we receive a communication error, retry the request up
 102                                 to XML_HTTP_MAX_TRIES attempts */
 103                         if( E && E.classname == "EXCommunication" ) {
 104
 105                                 if(object.sendCount >= XML_HTTP_MAX_TRIES ) {
 106                                         if(isXUL()) throw object;
 107                                          else alert("Arrrgghh, Matey! Error communicating:\n" + E  + "\n" + object.param_string);
 108                                 } else {
 109                                         object.buildXMLRequest();
 110                                         object.send();
 111                                         return;
 112                                 }
 113                         } else { throw E; }
 114
 115                 } finally {
 116                         destroyRequest(object);
 117                         object = null;
 118                 }
 119         }
 120 }
 121
 122
 123 /* define the callback we use when this request has received
 124         all of its data */
 125 RemoteRequest.prototype.setCompleteCallback = function(callback) {
 126         if(this.cancelled) return;
 127         this.callback = callback;
 128         var id = this.id;
 129         this.xmlhttp.onreadystatechange = function() { _remoteRequestCallback(id); }
 130 }
 131
 132
 133 /* http by default.  This makes it https. *ONLY works when
 134         embedded in a XUL app. */
 135 RemoteRequest.prototype.setSecure = function(bool) {
 136         this.secure = bool;
 137 }
 138
 139 RemoteRequest.prototype.send = function(blocking) {
 140
 141         if(this.cancelled) return;
 142
 143         /* determine the xmlhttp server dynamically */
 144         var url = location.protocol + "//" + location.host + "/" + XML_HTTP_GATEWAY;
 145
 146         if(isXUL()) {
 147                 if(this.secure)
 148                         url =   "https://" + XML_HTTP_SERVER + "/" + XML_HTTP_GATEWAY;
 149                 else
 150                         url =   "http://" + XML_HTTP_SERVER + "/" + XML_HTTP_GATEWAY;
 151         }
 152
 153         var data = null;
 154
 155         if( this.type == 'GET' ) {
 156                 url +=  "?" + this.param_string;
 157         }
 158
 159         if(blocking) {
 160                 this.xmlhttp.open(this.type, url, false);
 161         } else {
 162                 this.xmlhttp.open(this.type, url, true);
 163         }
 164
 165
 166         if( this.type == 'POST' ) {
 167                 data = this.param_string;
 168                 this.xmlhttp.setRequestHeader('Content-Type',
 169                                 'application/x-www-form-urlencoded');
 170         }
 171
 172         this.xmlhttp.send( data );
 173         this.sendCount += 1;
 174         return this;
 175 }
 176
 177 /* returns the actual response text from the request */
 178 RemoteRequest.prototype.getText = function() {
 179         return this.xmlhttp.responseText;
 180 }
 181
 182 RemoteRequest.prototype.isReady = function() {
 183         return this.xmlhttp.readyState == 4;
 184 }
 185
 186
 187 /* returns the JSON->js result object  */
 188 RemoteRequest.prototype.getResultObject = function() {
 189         if(this.cancelled) return null;
 190
 191         var text = this.xmlhttp.responseText;
 192         var obj = JSON2js(text);
 193
 194         if(obj == null) return null;
 195         if(obj.is_err)  throw new EXCommunication(obj.err_msg);
 196         if( obj[0] != null && obj[1] == null ) obj = obj[0];
 197
 198         /* these are user level exceptions from the server code */
 199         if(obj.__isfieldmapper && obj.classname == "ex") {
 200                 if(!isXUL()) alert(obj.err_msg());
 201                 throw obj;
 202         }
 203
 204         if(obj.__isfieldmapper && obj.classname == "perm_ex") {
 205                 /* the opac will go ahead and spit out the error msg */
 206                 if(!isXUL()) alert(obj.err_msg());
 207                 throw obj;
 208         }
 209
 210         return obj;
 211 }
 212
 213 /* adds a new parameter to the request */
 214 RemoteRequest.prototype.addParam = function(param) {
 215         var string = encodeURIComponent(js2JSON(param));
 216         this.param_string += "&param=" + string;
 217 }
 218