src/javascript/opensrf_xhr.js

   1 /* -----------------------------------------------------------------------
   2  * Copyright (C) 2008  Georgia Public Library Service
   3  * Bill Erickson <erickson@esilibrary.com>
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License
   7  * as published by the Free Software Foundation; either version 2
   8  * of the License, or (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  * ----------------------------------------------------------------------- */
  15
  16 var OSRF_HTTP_HEADER_TO = 'X-OpenSRF-to';
  17 var OSRF_HTTP_HEADER_XID = 'X-OpenSRF-xid';
  18 var OSRF_HTTP_HEADER_FROM = 'X-OpenSRF-from';
  19 var OSRF_HTTP_HEADER_THREAD = 'X-OpenSRF-thread';
  20 var OSRF_HTTP_HEADER_TIMEOUT = 'X-OpenSRF-timeout';
  21 var OSRF_HTTP_HEADER_SERVICE = 'X-OpenSRF-service';
  22 var OSRF_HTTP_HEADER_MULTIPART = 'X-OpenSRF-multipart';
  23 var OSRF_HTTP_TRANSLATOR = '/osrf-http-translator'; /* XXX config */
  24 var OSRF_POST_CONTENT_TYPE = 'application/x-www-form-urlencoded';
  25
  26
  27 OpenSRF.XHRequest = function(osrf_msg, args) {
  28     this.message = osrf_msg;
  29     this.args = args;
  30     try {
  31             this.xreq =  new XMLHttpRequest();
  32     } catch(e) {
  33             try {
  34                     this.xreq = new ActiveXObject("Msxml2.XMLHTTP");
  35             } catch (e2) {
  36                         this.xreq = new ActiveXObject("Microsoft.XMLHTTP");
  37             }
  38     }
  39
  40 }
  41
  42 OpenSRF.XHRequest.prototype.send = function() {
  43     var xhr_req = this;
  44     var xreq = this.xreq
  45
  46     if(this.args.timeout) {
  47         /* this is a standard blocking (non-multipart) call */
  48         xreq.open('POST', OSRF_HTTP_TRANSLATOR, false);
  49
  50     } else {
  51
  52         /* Only Firefox supports multipart calls, but Safari / Chrome include
  53            "Mozilla" in their user agent strings... sigh */
  54         if(!navigator.userAgent.match(/mozilla/i) || navigator.userAgent.match(/webkit/i)) {
  55             /* standard asynchronous call */
  56             xreq.onreadystatechange = function() {
  57                 if(xreq.readyState == 4)
  58                     xhr_req.core_handler();
  59             }
  60             xreq.open('POST', OSRF_HTTP_TRANSLATOR, true);
  61
  62         } else {
  63
  64             /* asynchronous multipart call */
  65             xreq.multipart = true;
  66             xreq.onload = function(evt) {xhr_req.core_handler();}
  67             xreq.open('POST', OSRF_HTTP_TRANSLATOR, true);
  68             xreq.setRequestHeader(OSRF_HTTP_HEADER_MULTIPART, 'true');
  69
  70             /* multipart requests do not pass the status info to the onload if there
  71                is no new data to load.  Capture the status on the readystate handler */
  72             xreq.onreadystatechange = function() {
  73                 if(xreq.readyState == 4 && xreq.status >= 400)
  74                     xhr_req.transport_error_handler();
  75             }
  76         }
  77     }
  78
  79     xreq.setRequestHeader('Content-Type', OSRF_POST_CONTENT_TYPE);
  80     xreq.setRequestHeader(OSRF_HTTP_HEADER_THREAD, this.args.thread);
  81     if(this.args.rcpt)
  82         xreq.setRequestHeader(OSRF_HTTP_HEADER_TO, this.args.rcpt);
  83     else
  84         xreq.setRequestHeader(OSRF_HTTP_HEADER_SERVICE, this.args.rcpt_service);
  85
  86     var post = 'osrf-msg=' + encodeURIComponent(js2JSON([this.message.serialize()]));
  87     xreq.send(post);
  88
  89     if(this.args.timeout) /* this was a blocking call, manually run the handler */
  90         this.core_handler()
  91
  92     return this;
  93 }
  94
  95 OpenSRF.XHRequest.prototype.core_handler = function() {
  96     sender = this.xreq.getResponseHeader(OSRF_HTTP_HEADER_FROM);
  97     thread = this.xreq.getResponseHeader(OSRF_HTTP_HEADER_THREAD);
  98     json = this.xreq.responseText;
  99     stat = this.xreq.status;
 100
 101     if(stat >= 400)
 102         return this.transport_error_handler();
 103
 104     OpenSRF.Stack.push(
 105         new OpenSRF.NetMessage(null, sender, thread, json),
 106         {
 107             onresponse : this.args.onresponse,
 108             oncomplete : this.args.oncomplete,
 109             onerror : this.args.onerror,
 110             onmethoderror : this.method_error_handler()
 111         }
 112     );
 113 }
 114
 115
 116 OpenSRF.XHRequest.prototype.method_error_handler = function() {
 117     var xhr = this;
 118     return function(req, status, status_text) {
 119         if(xhr.args.onmethoderror)
 120             xhr.args.onmethoderror(req, status, status_text);
 121         if(xhr.args.onerror)
 122             xhr.args.onerror(xhr.message, xhr.args.rcpt || xhr.args.rcpt_service, xhr.args.thread);
 123     }
 124 }
 125
 126 OpenSRF.XHRequest.prototype.transport_error_handler = function() {
 127     if(this.args.ontransporterror)
 128         this.args.ontransporterror(this.xreq);
 129     if(this.args.onerror)
 130         this.args.onerror(this.message, this.args.rcpt || this.args.rcpt_service, this.args.thread);
 131 }
 132
 133