"Getting 'Javascript is not a function' error with API.LMSInitialize(). How to fix?"

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#1

I’m encountering a “Javascript is not a function” error when trying to call API.LMSInitialize(“”) in my code.

I have defined a custom object like this: function Scorm_API_12() { var Initialized = false;

function LMSInitialize(param) {
    if (param == "") {
        if (!Initialized) {
            Initialized = true;
            return "true";
        }
    }
    return "false";
}

} var API = new Scorm_API_12();

In another script, I attempt to initialize the API: function ScormProcessInitialize() { API = getAPI(); if (API == null) { alert(“ERROR - Could not establish a connection.”); return; } var result = API.LMSInitialize(“”); }

The API seems to be found by getAPI(), but I still get the “LMSInitialize is not a function” error. Debugging shows API has no properties. What am I missing?

#2

Hello! To expose the LMSInitialize function, you can attach it to the object instance using this, which makes the function publicly accessible as a method of the object. Here’s how you can do it:

Currently, LMSInitialize is a private function within the constructor scope of the Scorm_API_12 function. By using this, you’re essentially making it part of the object’s instance, enabling external access.

function Scorm_API_12() {
    var Initialized = false;

    this.LMSInitialize = function (param) {  // Attach to this
        if (param == "") {
            if (!Initialized) {
                Initialized = true;
                return "true";
            }
        }
        return "false";
    };
}

Now, LMSInitialize will be accessible as a method of the Scorm_API_12 instance, allowing external code to call it and interact with it. This way, you maintain the necessary control over initialization while making the function available for use.

Thanks!

#3

Hello everyone!

To optimize your implementation of the LMSInitialize function, consider declaring it using the prototype of the Scorm_API_12 constructor. This approach ensures that the function is shared across all instances, promoting code efficiency and clarity. Here’s how you can do it:

function Scorm_API_12() {
    this.Initialized = false;
}

Scorm_API_12.prototype.LMSInitialize = function(param) {
    if (param === "") {
        if (!this.Initialized) {
            this.Initialized = true;
            return "true";
        }
    }
    return "false";
};

By using the prototype for the LMSInitialize function, you maintain a clean structure while ensuring that the method is accessible to all instances of Scorm_API_12. This not only enhances memory efficiency but also streamlines your code.

Feel free to reach out if you have any further Questions.

#4

Hello everyone! If you encounter the “Javascript is not a function” error even when your method is correctly defined, the problem may lie in how the API is being retrieved. Please ensure that the getAPI() function returns a valid instance of Scorm_API_12 and not null. Here’s a refined version of the function to clarify:

function getAPI() {
    var theAPI = new Scorm_API_12(); // Ensure this creates a valid API instance
    return theAPI;
}

By doing this, when you assign API = getAPI(), it should correctly point to the instance of Scorm_API_12, allowing your code to function properly. If you continue to face issues, double-check any dependencies or initializations that might affect the API retrieval.