How To Troubleshoot Knockout JS Errors In Magneto 2?

How To Troubleshoot Knockout JS Errors In Magneto 2?

What Is Knockout JS?

Knockout JS is a JavaScript library that helps to create responsive displays and an easy user interface. If you have sections of UI that update dynamically, KnockOut may help you implement those sections quickly.

1) Binding Errors

This is the most common error we face while binding data using js components in the layout file. You encounter this error might be due to wrong data binding or incorrect syntax. There are several ways to overcome this error. But the challenging task is to identify which data are being used for binding or which component is used for the binding.

2) Failed To Load Component

While implementing the Knockout js section, you might have seen the error in loading components. The js file shows status code 404. There are multiple ways you can include the JS component. So it depends on how you have implemented the JS.

Include js Using XML Layout

You need to mention the vendor name and module name while adding js. Here is the syntax for XML layout

3) Debug With Chrome DevTools

All the latest browsers support a debugging tool to find and fix errors more easily. Let’s consider you are using the chrome browser. Follow the below steps to use debugging tools.

  • Right-click and click on inspect element or press F12
  • Click on the sources tab
  • Open your loaded file using Ctrl + P

4) Undefined Variable

This is another most common issue after binding. When you bind the property of a variable that is not defined in the component, then it will show the error of an undefined variable. You can trace this error from the browser console and also check the related component path as well.

Final Notes

Knockout js the javascript library, so you need to be careful when finding any exceptions in components while debugging and fixing those errors. If knockout js finds any exception at the starting, it will not render the complete section. The best practice is to use the try and catch inside your component. In case you want help to troubleshoot knockout JS in Magento 2, you can connect with our team to hire Magento developers. Also, knockout js will always throw an exception from the core library. I strongly do not recommend debugging the core library.

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