jnm2 · November 15, 2016 04:10 · Nov 16, 2012 · May 18, 2012 · May 17, 2012 · May 7, 2012
diff --git a/waitForKeyElements.js b/waitForKeyElements.js
@@ -83,7 +83,7 @@ function waitForKeyElements (
                                             iframeSelector
                                         );
                 },
-                500
+                300
             );
             controlObj [controlKey] = timeControl;
         }

diff --git a/waitForKeyElements.js b/waitForKeyElements.js
@@ -40,6 +40,7 @@ function waitForKeyElements (
                                            .find (selectorTxt);
 
     if (targetNodes  &&  targetNodes.length > 0) {
+        btargetsFound   = true;
         /*--- Found target node(s).  Go through each and act if they
             are new.
         */
@@ -49,11 +50,13 @@ function waitForKeyElements (
 
             if (!alreadyFound) {
                 //--- Call the payload function.
-                jThis.data ('alreadyFound', true);
-                actionFunction (jThis);
+                var cancelFound     = actionFunction (jThis);
+                if (cancelFound)
+                    btargetsFound   = false;
+                else
+                    jThis.data ('alreadyFound', true);
             }
         } );
-        btargetsFound   = true;
     }
     else {
         btargetsFound   = false;

diff --git a/waitForKeyElements.js b/waitForKeyElements.js
@@ -49,8 +49,8 @@ function waitForKeyElements (
 
             if (!alreadyFound) {
                 //--- Call the payload function.
-                actionFunction (jThis);
                 jThis.data ('alreadyFound', true);
+                actionFunction (jThis);
             }
         } );
         btargetsFound   = true;

diff --git a/waitForKeyElements.js b/waitForKeyElements.js
@@ -0,0 +1,89 @@
+/*--- waitForKeyElements():  A utility function, for Greasemonkey scripts,
+    that detects and handles AJAXed content.
+
+    Usage example:
+
+        waitForKeyElements (
+            "div.comments"
+            , commentCallbackFunction
+        );
+
+        //--- Page-specific function to do what we want when the node is found.
+        function commentCallbackFunction (jNode) {
+            jNode.text ("This comment changed by waitForKeyElements().");
+        }
+
+    IMPORTANT: This function requires your script to have loaded jQuery.
+*/
+function waitForKeyElements (
+    selectorTxt,    /* Required: The jQuery selector string that
+                        specifies the desired element(s).
+                    */
+    actionFunction, /* Required: The code to run when elements are
+                        found. It is passed a jNode to the matched
+                        element.
+                    */
+    bWaitOnce,      /* Optional: If false, will continue to scan for
+                        new elements even after the first match is
+                        found.
+                    */
+    iframeSelector  /* Optional: If set, identifies the iframe to
+                        search.
+                    */
+) {
+    var targetNodes, btargetsFound;
+
+    if (typeof iframeSelector == "undefined")
+        targetNodes     = $(selectorTxt);
+    else
+        targetNodes     = $(iframeSelector).contents ()
+                                           .find (selectorTxt);
+
+    if (targetNodes  &&  targetNodes.length > 0) {
+        /*--- Found target node(s).  Go through each and act if they
+            are new.
+        */
+        targetNodes.each ( function () {
+            var jThis        = $(this);
+            var alreadyFound = jThis.data ('alreadyFound')  ||  false;
+
+            if (!alreadyFound) {
+                //--- Call the payload function.
+                actionFunction (jThis);
+                jThis.data ('alreadyFound', true);
+            }
+        } );
+        btargetsFound   = true;
+    }
+    else {
+        btargetsFound   = false;
+    }
+
+    //--- Get the timer-control variable for this selector.
+    var controlObj      = waitForKeyElements.controlObj  ||  {};
+    var controlKey      = selectorTxt.replace (/[^\w]/g, "_");
+    var timeControl     = controlObj [controlKey];
+
+    //--- Now set or clear the timer as appropriate.
+    if (btargetsFound  &&  bWaitOnce  &&  timeControl) {
+        //--- The only condition where we need to clear the timer.
+        clearInterval (timeControl);
+        delete controlObj [controlKey]
+    }
+    else {
+        //--- Set a timer, if needed.
+        if ( ! timeControl) {
+            timeControl = setInterval ( function () {
+                    waitForKeyElements (    selectorTxt,
+                                            actionFunction,
+                                            bWaitOnce,
+                                            iframeSelector
+                                        );
+                },
+                500
+            );
+            controlObj [controlKey] = timeControl;
+        }
+    }
+    waitForKeyElements.controlObj   = controlObj;
+}