SCORM 2004 API discovery algorithm
As anybody is free, writing his own SCORM 2004 API discovery algorithm, here's the suggested version of Mike Rustici from Rustici Software [1]. Taken from their website [2] and slightly modified for better readability.
var MAX_PARENTS_TO_SEARCH = 500;
/**
* ScanParentsForApi
*
* Searches all the parents of a given window until it finds an object named
* "API_1484_11". If an object of that name is found, a reference to it is
* returned. Otherwise, this function returns null.
*/
function ScanParentsForApi(win) {
/**
* Establish an outrageously high maximum number of parent windows that we are
* will to search as a safe guard against an infinite loop. This is probably not
* strictly necessary, but different browsers can do funny things with undefined
* objects.
*/
var nParentsSearched = 0;
/**
* Search each parent window until we either:
* -find the API,
* -encounter a window with no parent (parent is null or the same as the current
* window)
* -or, have reached our maximum nesting threshold
*/
while ((win.API_1484_11 == null) && (win.parent != null) && (win.parent != win) && (nParentsSearched <= MAX_PARENTS_TO_SEARCH)) {
nParentsSearched++;
win = win.parent;
}
/**
* If the API doesn't exist in the window we stopped looping on, then this will
* return null.
*/
return win.API_1484_11;
}
/**
* GetAPI
* -Searches all parent and opener windows relative to the current window for
* the SCORM 2004 API Adapter.
* Returns a reference to the API Adapter if found or null otherwise.
*/
function GetApi() {
var API = null;
//Search all the parents of the current window if there are any
if ((window.parent != null) && (window.parent != window)) {
API = ScanParentsForApi(window.parent);
}
/**
* If we didn't find the API in this window's chain of parents, then search
* all the parents of the opener window if there is one
*/
if ((API == null) && (window.top.opener != null)) {
API = ScanParentsForApi(window.top.opener);
}
return API;
}
/**
* Sample usage
*/
var objScormApi;
objScormApi = GetApi();
// If we didn't find the API, alert the user note - you might want to disable
// future attempts at calling API functions at this point
if (objScormApi == null){
alert('Error finding API instance');
}
objScormApi.Initialize('');[1] http://www.scorm.com/
[2] http://www.scorm.com/resources/apifinder/SCORMAPIFinder.htm
Updated SCORM wrapper
hi sanduhrs
I recently created a custom rewrite of the SCORM wrapper, using a slightly modified version of Mike Rustici's API discovery code. You might find it interesting.
http://pipwerks.com/lab/scorm/wrapper/index.html
cheers :)
- philip
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