Credits
['lookang']
Integrating xAPI with EJS Simulations: A Step-by-Step Guide
If you're an EJS (Easy JavaScript Simulations) user looking to enhance your simulations with xAPI (Experience API) capabilities, you've come to the right place. This guide will walk you through the process of integrating xAPI into your EJS simulations using a totalScore
variable. We'll provide detailed instructions and code snippets to make the integration seamless.
What is xAPI?
xAPI is a specification that allows learning content and learning systems to communicate with each other about learner actions. It enables the collection of data about a wide range of experiences a learner has (both online and offline). By integrating xAPI into your EJS simulations, you can track user interactions, scores, and more.
Prerequisites
- Basic Knowledge of EJS: Familiarity with creating and editing EJS simulations.
- Understanding of JavaScript: Basic knowledge to modify and insert code.
- xAPI Endpoint and Credentials: Access to an LRS (Learning Record Store) endpoint, along with authentication details.
Overview
We'll modify your EJS simulation to:
- Include the xAPI Wrapper library. sample file
sample-html5corrected.zip - The final sample xAPI_WebEJS is here webejs_model_xAPI_WebEJS.zip
- comment out the unnecessary parameters for the document etc
- Initialize the
totalScore
variable. - Send the
totalScore
to the LRS whenever it changes.
Step-by-Step Integration
1. Include the xAPI Wrapper Library
First, you need to include the xAPI Wrapper library in your EJS simulation. This library simplifies sending xAPI statements to an LRS.
Action:
- Download the
xapiwrapper.min.js
file from the official repository. - Place it in the same directory as your EJS simulation or host it on your server.
Insert the following script tag in your HTML file (usually in the <head>
section):
2. Extract Parameters from the URL
We'll use URL parameters to pass the endpoint, authentication, actor, and activity ID to the simulation.
Add the following function to your EJS custom function source code:
Explanation:
- Endpoint: The LRS endpoint where xAPI statements will be sent.
- Auth: The Base64-encoded authentication string.
- Actor: The user's identifier.
- Activity ID: The unique identifier for the simulation activity.
3. Initialize the totalScore
Variable
Ensure that your simulation has a totalScore
variable that keeps track of the user's score.
Action:
4. Send the totalScore
to the LRS
We'll create a function that sends the current totalScore
to the LRS whenever it changes.
Add the following function to your EJS source code:
Explanation:
- sendState(): Sends the state document (in this case, the
totalScore
) to the LRS. - Parameters:
- Activity ID: From
parameters.activity_id
. - Actor: From
parameters.actor
. - Registration:
null
(optional, can be used if you have a registration ID). - State Data: An object containing the
score
.
- Activity ID: From
5. Update totalScore
and Trigger Data Sending
Whenever the totalScore
changes within your simulation, ensure that sendTotalScore()
is called.
Action:
- Identify where
sendState(1)
sendState(2)
sendState(3)
for 1,2,3 marks to be given
6. Modify the Simulation's HTML (Optional)
If you have interactive elements like buttons to adjust the score, ensure they call the appropriate functions.
Example HTML:
<button onclick="sendState(5)">5</button>
<button onclick="sendState(5)">5</button>
7. Testing the Integration
Before deploying, test the integration to ensure data is being sent correctly.
Steps:
-
Run the Simulation with URL Parameters:
Append the necessary parameters to your simulation's URL:
Example:
-
Interact with the Simulation:
Perform actions that modify the
totalScore
. -
Check the LRS:
Log in to your LRS and verify that the state documents are being received.
8. Handling Authentication Securely
For security, avoid exposing the authentication details in the URL in a production environment.
Recommendation:
- Use server-side code to inject the
auth
parameter securely. - Consider implementing OAuth or another secure authentication method.
9. Advanced: Customize xAPI Statements
If you wish to send more detailed xAPI statements, you can customize them further.
Example of Sending an xAPI Statement:
Action:
- Replace
sendTotalScore()
calls withsendScoreStatement()
if you prefer sending statements over state documents.
Full Code Example
Here's how your EJS source code might look after integration:
Conclusion
By following this guide, you can integrate xAPI into your EJS simulations, allowing you to track and store user interactions and scores in an LRS. This enhances the learning experience by enabling data-driven insights and personalized feedback.
Remember:
- Always test your integration thoroughly.
- Secure your authentication details.
- Explore xAPI's capabilities to enrich your simulations further.
References:
Happy simulating!
Analysis of the code
The provided code is a simple web application designed to interact with the SLS (let's assume SLS stands for "Sample Learning System" or similar) by sending user interaction data to it. The key purpose of this application is to capture user inputs (like score adjustments) and send this data to SLS's new interactive response item type using the xAPI (Experience API) standard.
Here's a detailed explanation of how the code works to send data to SLS's new interactive response item type:
Overview
-
HTML Structure (
index.html
): The HTML file sets up the web page with buttons that the user can click to adjust a score value. It also includes sections to display developer info, cookies, and results. -
JavaScript Logic (
index.js
): This script handles the logic of capturing user interactions, updating the score, and sending the data to SLS using the xAPIWrapper library. -
xAPIWrapper Library (
xapiwrapper.min.js
): This is a JavaScript library that simplifies interactions with Learning Record Stores (LRS) using the xAPI standard.
Step-by-Step Explanation
1. Loading Necessary Scripts
- xAPIWrapper Library: Provides functions to send xAPI statements to an LRS.
- Custom Script (
index.js
): Contains the logic to handle user interactions and data submission.
2. Capturing URL Parameters
- Purpose: Extracts necessary parameters from the URL to configure the xAPI wrapper and identify the user and activity.
- Parameters Captured:
- Endpoint: The LRS endpoint where data will be sent.
- Auth: Authentication token for secure communication.
- Actor: Represents the user interacting with the application.
- Activity ID: Identifies the specific activity or question in SLS.
3. Initializing and Updating the Score
- Purpose: Initializes a variable to keep track of the user's total score.
4. Handling User Interactions
- Purpose: When a user clicks a button, it calls the
sendState
function with a specific value (positive or negative numbers, or 'randomText').
5. Updating the Score and Sending Data
-
Updating the Score:
- If
totalScore
is'randomText'
, reset it to0
. - If
answer
is'randomText'
, settotalScore
to'randomText'
. - Otherwise, adjust
totalScore
by adding theanswer
value.
- If
-
Sending Data to SLS:
- Retrieve Parameters: Calls
getParameters()
to get the latest configuration. - Prepare State Data: Creates an object
stateval
containing the currentscore
. - Send State Data:
- Uses
ADL.XAPIWrapper.sendState()
to send the state data to the LRS. - Parameters:
- Activity ID: Constructs a URL identifying the activity/question.
- Agent: Represents the user (hardcoded here as "mailto:This email address is being protected from spambots. You need JavaScript enabled to view it." for demonstration purposes).
- Registration: Uses the
actor
from the URL parameters. - State ID:
null
(could be used to specify a particular state document). - State Data: The
stateval
object containing the score.
- Uses
- Retrieve Parameters: Calls
-
Updating the UI:
- On success, displays "Score Submitted: " along with the current
totalScore
. - On error, logs the error and displays an error message on the page.
- On success, displays "Score Submitted: " along with the current
6. Configuring the xAPI Wrapper
- Purpose: Sets up the xAPI wrapper with the endpoint and authentication details so that it can communicate with the LRS securely.
How It Integrates with SLS's New Interactive Response Item Type
-
Interactivity: The application provides interactive elements (buttons) that simulate user responses or score adjustments.
-
Data Capture: Each interaction updates the
totalScore
and prepares it to be sent as part of the state data. -
xAPI Communication: By using the xAPI standard and the
sendState
function, the application sends the user's state (current score) to the SLS's LRS. -
Activity Identification: The
activity_id
ensures that the data is associated with the correct activity or question within SLS. -
User Identification: The
actor
parameter links the state data to the specific user, enabling SLS to track individual user responses.
Important Considerations
-
Authentication and Security: The
auth
parameter should be securely handled. In a production environment, it should not be exposed in the URL or client-side scripts. -
Agent Representation: The agent is currently hardcoded as
{"mbox":"mailto:This email address is being protected from spambots. You need JavaScript enabled to view it."}
. In a real-world scenario, this should dynamically represent the actual user's email or unique identifier. -
Error Handling: The code includes basic error handling to catch and display errors that may occur during the data submission process.
-
Extensibility: The application can be extended to handle more complex interactions or additional data types as required by SLS's new interactive response item type.
Summary
- The application captures user interactions through button clicks.
- It updates a
totalScore
based on these interactions. - It sends the updated score to SLS using the xAPI standard via the
sendState
function. - The xAPI wrapper handles the communication with the LRS at the specified endpoint.
- The use of URL parameters allows dynamic configuration and integration with SLS.
By following this flow, the application effectively sends data to SLS's new interactive response item type, allowing SLS to record and process user responses in a standardized format.
- Details
- Written by Loo Kang Wee
- Category: How to
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