fad6336881fbfae98fe0bda10ed9955fd7a85fe9
tdreszer
  Tue Sep 7 14:18:05 2010 -0700
Tangled code that allows form submits to wait for outstanding ajax completion.
diff --git src/hg/js/ajax.js src/hg/js/ajax.js
index f40c3e9..561c955 100644
--- src/hg/js/ajax.js
+++ src/hg/js/ajax.js
@@ -1,184 +1,284 @@
 // AJAX Utilities
 
 var debug = false;
 
 var req;
 
 function nullProcessReqChange()
 {
-    if(debug)
+    if(debug && this.readyState == 4)
             alert("req.responseText: " + req.responseText);
 }
 
+// When setting vars with ajax, it may be necessary to wait for response before newer calls
+// Therefore this counter is set up to allow an "outside callback" when the ajax is done
+// The typical scenario is setCartVar by ajax, followed immmediately by a form submit.
+// To avoid the race condition, the form gets submitted after the ajax returns
+var ajaxWaitCount = 0;
+function ajaxWaitIsDone()     { return ( ajaxWaitCount <= 0 ); }
+function ajaxWaitCountUp()    { ajaxWaitCount++; }
+function ajaxWaitCountReset() { ajaxWaitCount = 0; }
+//function ajaxWaitCountShow()  { warn("ajaxWait calls outstanding:"+ajaxWaitCount); }
+
+// Here is where the "outside callback" gets set up and called
+var ajaxWaitCallbackFunction = null;
+var ajaxWaitCallbackTimeOut = null;
+function ajaxWaitCallbackRegister(func)
+{ // register a function to be called when the ajax waiting is done.
+    if(ajaxWaitIsDone())
+        func();
+    else {
+        ajaxWaitCallbackFunction = func;
+        ajaxWaitCallbackTimeOut = setTimeout("ajaxWaitCallback();",5000);  // just in case
+    }
+}
+
+function ajaxWaitCallback()
+{ // Perform the actual function (which could have been because of a callback or a timeout)
+    // Clear the timeout if this is not due to ajaxWaitDone
+    //warn("ajaxWaitCallback: "+ajaxWaitIsDone());
+    if(ajaxWaitCallbackTimeOut != null) {
+        clearTimeout(ajaxWaitCallbackTimeOut);
+        ajaxWaitCallbackTimeOut = null;
+    }
+    // Clear the wait stack incase something failed and we are called by a timeout
+    ajaxWaitCountReset();
+
+    // Finally do the function
+    if(ajaxWaitCallbackFunction
+    && jQuery.isFunction(ajaxWaitCallbackFunction)) {
+        ajaxWaitCallbackFunction();
+    }
+    ajaxWaitCallbackFunction = null;
+}
+
+function ajaxWaitCountDown()
+{ // called whenever an ajax request is done
+    if((req && req.readyState == 4)
+    || (this.readyState == 4))
+    { // It is only state 4 that means done
+        ajaxWaitCount--;
+        if(ajaxWaitIsDone())
+            ajaxWaitCallback();
+    }
+    //warn(req.readyState + " waiters:"+ajaxWaitCount);
+}
+
+var formToSubmit = null; // multistate: null, {form}, "COMPLETE", "ONCEONLY"
+var formSubmitPhase = 0;
+function formSubmit()
+{ // This will be called as a callback on timeout or ajaxWaitCallback
+
+    if(formToSubmit != null) {
+        //warn("submitting form:"+$(formToSubmit).attr('name') + ": "+ajaxWaitIsDone());
+        var form = formToSubmit;
+        formToSubmit = "GO"; // Flag to wait no longer
+        $(form).submit();
+    }
+    waitMaskClear(); // clear any outstanding waitMask.  overkill if the form has just been submitted
+}
+function formSubmitRegister(form)
+{ // Registers the form submit to be done by ajaxWaitCallback or timeout
+    if(formToSubmit != null) // Repeated submission got through, so ignore it
+        return false;
+    waitMaskSetup(5000);     // Will prevent repeated submissions, I hope.
+    formToSubmit = form;
+    //warn("Registering form to submit:"+$(form).attr('name'));
+    ajaxWaitCallbackRegister(formSubmit);
+    return false; // Don't submit until ajax is done.
+}
+
+function formSubmitWaiter(e)
+{ // Here we will wait for up to 5 seconds before continuing.
+    if(formToSubmit == null)
+        return formSubmitRegister(e.target); // register on first time through
+
+    if(formToSubmit == "GO") {  // Called again as complete
+        //warn("formSubmitWaiter(): GO");
+        formToSubmit = "STOP";  // Do this only once!
+        return true;
+    }
+    return false;
+}
+
+function formSubmitWaitOnAjax(form)
+{ // Most typically, we block a form submit until all ajax has returned
+    $(form).unbind('submit', formSubmitWaiter ); // prevents multiple bind requests
+    $(form).bind(  'submit', formSubmitWaiter );
+}
+
 function loadXMLDoc(url)
 {
 // Load XML without a request handler; this is useful if you are sending one-way messages.
         loadXMLDoc(url, null);
 }
 
 function loadXMLDoc(url, callBack)
 {
 // From http://developer.apple.com/internet/webcontent/xmlhttpreq.html
+    //warn("AJAX started: "+url);
     if(callBack == null)
         callBack = nullProcessReqChange;
     req = false;
     // branch for native XMLHttpRequest object
     if(window.XMLHttpRequest && !(window.ActiveXObject)) {
         try {
             req = new XMLHttpRequest();
         } catch(e) {
             req = false;
         }
     } else if(window.ActiveXObject) {
         // branch for IE/Windows ActiveX version
         try {
             req = new ActiveXObject("Msxml2.XMLHTTP");
         } catch(e) {
             try {
                 req = new ActiveXObject("Microsoft.XMLHTTP");
             } catch(e) {
                 req = false;
             }
         }
     }
     if(debug)
         alert(url);
     if(req) {
         req.onreadystatechange = callBack;
         req.open("GET", url, true);
-        req.send("");
+        req.send();
+        //req.send("");
     }
 }
 
 function setCartVars(names, values)
 {
 // Asynchronously sets the array of cart vars with values
     if(names.length <= 0)
         return;
 
     // Set up constant portion of url
     var loc = window.location.href;
     if(loc.indexOf("?") > -1) {
         loc = loc.substring(0, loc.indexOf("?"));
     }
     if(loc.lastIndexOf("/") > -1) {
         loc = loc.substring(0, loc.lastIndexOf("/"));
     }
     loc = loc + "/cartDump";
     var hgsid = getHgsid();
     loc = loc + "?submit=1&noDisplay=1&hgsid=" + hgsid;
 
     // Set up dynamic portion of url
     var ix=0;
     while( ix < names.length ) { // Sends multiple messages if the URL gets too long
         var pairs = "";
         for(  ;ix<names.length && pairs.length < 5000;ix++) {  // FIXME: How big is too big?
             //pairs = pairs + "&cartDump.varName=" + escape(names[ix]) + "&cartDump.newValue=" + escape(values[ix]);
             pairs = pairs + "&" + escape(names[ix]) + "=" + escape(values[ix]);
         }
         if(pairs.length == 0)
             return;
         //warn(pairs);
-        loadXMLDoc(loc + pairs);
+        ajaxWaitCountUp();
+        loadXMLDoc(loc + pairs,ajaxWaitCountDown);
     }
 }
 
 function setCartVar(name, value)
 {
 // Asynchronously set a cart variable.
     setCartVars( [ name ], [ value ] );
 }
 
 function setVarsFromHash(varHash)
 {
 // Set all vars in a var hash
 // If obj is undefined then obj is document!
     var names = [];
     var values = [];
     for (var aVar in varHash) {
         names.push(aVar);
         values.push(varHash[aVar]);
     }
     if(names.length > 0) {
         setCartVars(names,values);
     }
 }
 
 function setAllVars(obj,subtrackName)
 {
 // Set all enabled inputs and selects found as children obj with names to cart with ajax
 // If obj is undefined then obj is document!
     var names = [];
     var values = [];
     if($(obj) == undefined)
         obj = $('document');
 
     setVarsFromHash(getAllVars(obj,subtrackName));
 }
 
 function setCartVarFromObjId(obj)
 {
     setCartVar($(obj).attr('id'),$(obj).val());
 }
 
 function submitMain()
 {
     $('form[name="mainForm"]').submit();
 }
 
 function setCartVarAndRefresh(name,val)
 {
     setCartVar(name,val);
     var main=$('form[name="mainForm"]')
     $(main).attr('action',window.location.href);
     setTimeout("submitMain()",50);  // Delay in submit helps ensure that cart var has gotten there first.
 
     return false;
 }
 
 function catchErrorOrDispatch(obj, status)
 {
 // generic ajax success handler (handles fact that success is not always success).
     if(status == 'success')
         this.trueSuccess(obj, status);
     else
     {
         showWarning("ajax error: " + status);
         jQuery('body').css('cursor', '');
     }
 }
 
 function showWarning(str)
 {
     $("#warningText").text(str);
     $("#warning").show();
 }
 
 // Specific calls...
 function lookupMetadata(tableName,showLonglabel,showShortLabel)
 { // Ajax call to repopulate a metadata vals select when mdb var changes
     //warn("lookupMetadata for:"+tableName);
     var thisData = "db=" + getDb() +  "&cmd=tableMetadata&track=" + tableName;
     if(showLonglabel)
         thisData += "&showLonglabel=1";
     if(showShortLabel)
         thisData += "&showShortLabel=1";
     $.ajax({
         type: "GET",
         url: "../cgi-bin/hgApi",
         data: thisData,
         trueSuccess: loadMetadataTable,
         success: catchErrorOrDispatch,
         cache: true,
         cmd: tableName
     });
 }
 
 function loadMetadataTable(response, status)
 // Handle ajax response (repopulate a metadata val select)
 {
     var div = $("div#div_"+this.cmd+"_meta");
     $(div).html(response);
     $(div).show();
 }