---
title: "Onboard callback function"
slug: "onload-callback-function"
updated: 2024-01-18T15:01:38Z
published: 2024-01-18T15:01:38Z
canonical: "help.movingimage.com/onload-callback-function"
---
> ## Documentation Index
> Fetch the complete documentation index at: https://help.movingimage.com/llms.txt
> Use this file to discover all available pages before exploring further.
# Onload callback function
## Implement a callback function for dynamic player loading
### **Description**
This tutorial shows you how to implement a callback function that allows you to execute code as soon as a Player loads. The function can contain several actions that are called when the API of the respective Player loads. The code in this tutorial introduces the recommended approach for dynamically adding a player on load.
> **Note:** When lazy loading is enabled, the Player will not be accessible through the API until a user clicks play. This is an inherent quality of the lazy loading feature, which prevents the Player from loading until a user clicks play. Find more information on lazy loading here.
### **Example**
The following code shows the recommended approach for adding a player on load. This example will play and mute the video as soon as the Player loads:
HTML
```plainText
```
**Note:** You need to specify the necessary IDs and URLs in the `initPlayer` object.
**Use the callback function**
The `success` property in the `initPlayer` object defines the function you want to execute as soon as the Player loads (the callback function). When you pass the `initPlayer` object to the `addPlayerById` function, the Player object is sent to your callback function. You can then use the Player object to make API calls.
For a list of other API functions available, see the Basic Functions Reference.
**Add the Player script**
The `embed.js` script file is added to the `head` tag dynamically with JavaScript. This is the best way to add the `embed.js` file because it facilitates correct timing and order of operations by allowing you to use the script's `onload` property to initiate the creation of your Player.
**Create the Player**
The `createPlayer` function is called when the `embed.js` script loads. This function creates an `initPlayer` object to pass into the API's `addPlayerById` function. The `parameters` property in the `initPlayer` object should use the attributes from your embed code. This allows you to set up an empty div, `player_container` as a placeholder and add these properties dynamically when the player is created.
**Conclusion**
This tutorial has shown you how to implement a callback function that allows you to execute code as soon as a Player loads. The function can contain several actions that are called when the API of the respective Player loads. The code in this tutorial introduced the recommended approach for dynamically adding a player on load.