Open-ILS/src/javascript/lib/js/opac/RemoteRequest.js

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