1 files changed, 137 insertions, 0 deletions
diff --git a/SemanticResultFormats/formats/Exhibit/ajax/scripts/xmlhttp.js b/SemanticResultFormats/formats/Exhibit/ajax/scripts/xmlhttp.js
new file mode 100644
index 00000000..b6d2c0aa
--- /dev/null
+++ b/SemanticResultFormats/formats/Exhibit/ajax/scripts/xmlhttp.js
@@ -0,0 +1,137 @@
+/**
+ * @fileOverview XmlHttp utility functions
+ * @name SimileAjax.XmlHttp
+ */
+
+SimileAjax.XmlHttp = new Object();
+
+/**
+ *  Callback for XMLHttp onRequestStateChange.
+ */
+SimileAjax.XmlHttp._onReadyStateChange = function(xmlhttp, fError, fDone) {
+    switch (xmlhttp.readyState) {
+    // 1: Request not yet made
+    // 2: Contact established with server but nothing downloaded yet
+    // 3: Called multiple while downloading in progress
+    
+    // Download complete
+    case 4:
+        try {
+            if (xmlhttp.status == 0     // file:// urls, works on Firefox
+             || xmlhttp.status == 200   // http:// urls
+            ) {
+                if (fDone) {
+                    fDone(xmlhttp);
+                }
+            } else {
+                if (fError) {
+                    fError(
+                        xmlhttp.statusText,
+                        xmlhttp.status,
+                        xmlhttp
+                    );
+                }
+            }
+        } catch (e) {
+            SimileAjax.Debug.exception("XmlHttp: Error handling onReadyStateChange", e);
+        }
+        break;
+    }
+};
+
+/**
+ *  Creates an XMLHttpRequest object. On the first run, this
+ *  function creates a platform-specific function for
+ *  instantiating an XMLHttpRequest object and then replaces
+ *  itself with that function.
+ */
+SimileAjax.XmlHttp._createRequest = function() {
+    if (SimileAjax.Platform.browser.isIE) {
+        var programIDs = [
+        "Msxml2.XMLHTTP",
+        "Microsoft.XMLHTTP",
+        "Msxml2.XMLHTTP.4.0"
+        ];
+        for (var i = 0; i < programIDs.length; i++) {
+            try {
+                var programID = programIDs[i];
+                var f = function() {
+                    return new ActiveXObject(programID);
+                };
+                var o = f();
+                
+                // We are replacing the SimileAjax._createXmlHttpRequest
+                // function with this inner function as we've
+                // found out that it works. This is so that we
+                // don't have to do all the testing over again
+                // on subsequent calls.
+                SimileAjax.XmlHttp._createRequest = f;
+                
+                return o;
+            } catch (e) {
+                // silent
+            }
+        }
+        // fall through to try new XMLHttpRequest();
+    }
+
+    try {
+        var f = function() {
+            return new XMLHttpRequest();
+        };
+        var o = f();
+        
+        // We are replacing the SimileAjax._createXmlHttpRequest
+        // function with this inner function as we've
+        // found out that it works. This is so that we
+        // don't have to do all the testing over again
+        // on subsequent calls.
+        SimileAjax.XmlHttp._createRequest = f;
+        
+        return o;
+    } catch (e) {
+        throw new Error("Failed to create an XMLHttpRequest object");
+    }
+};
+
+/**
+ * Performs an asynchronous HTTP GET.
+ *  
+ * @param {Function} fError a function of the form 
+     function(statusText, statusCode, xmlhttp)
+ * @param {Function} fDone a function of the form function(xmlhttp)
+ */
+SimileAjax.XmlHttp.get = function(url, fError, fDone) {
+    var xmlhttp = SimileAjax.XmlHttp._createRequest();
+    
+    xmlhttp.open("GET", url, true);
+    xmlhttp.onreadystatechange = function() {
+        SimileAjax.XmlHttp._onReadyStateChange(xmlhttp, fError, fDone);
+    };
+    xmlhttp.send(null);
+};
+
+/**
+ * Performs an asynchronous HTTP POST.
+ *  
+ * @param {Function} fError a function of the form 
+     function(statusText, statusCode, xmlhttp)
+ * @param {Function} fDone a function of the form function(xmlhttp)
+ */
+SimileAjax.XmlHttp.post = function(url, body, fError, fDone) {
+    var xmlhttp = SimileAjax.XmlHttp._createRequest();
+    
+    xmlhttp.open("POST", url, true);
+    xmlhttp.onreadystatechange = function() {
+        SimileAjax.XmlHttp._onReadyStateChange(xmlhttp, fError, fDone);
+    };
+    xmlhttp.send(body);
+};
+
+SimileAjax.XmlHttp._forceXML = function(xmlhttp) {
+    try {
+        xmlhttp.overrideMimeType("text/xml");
+    } catch (e) {
+        xmlhttp.setrequestheader("Content-Type", "text/xml");
+    }
+};
+\ No newline at end of file