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