Resolving the undefined Error When Accessing Object Properties in Express with EJS

Discover how to effectively access JavaScript object properties passed from EJS in Express. Learn to solve the `undefined` issue when dealing with form submissions.
---

Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: Can't get a specific property of js object

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
Resolving the undefined Error When Accessing Object Properties in Express with EJS

When developing web applications, we frequently encounter situations where we need to pass data between the front-end and the back-end. A common challenge arises when attempting to access specific properties of JavaScript objects that are sent from an EJS template to an Express server. If you've faced a situation where you receive an object but find yourself unable to access its properties, don’t worry! In this guide, we’ll walk through the problem and provide a step-by-step solution.

The Problem

Example Scenario

In this example, your EJS code to create the Edit button looks like this:

[[See Video to Reveal this Text or Code Snippet]]

And in your Express route handling the POST request:

[[See Video to Reveal this Text or Code Snippet]]

The Culprit: String Formatting

The main issue here is that the value being sent from the EJS template is in String format, not as a JavaScript object. When you try to access a property like title on a string, you’ll always get undefined, as strings don’t have properties like objects do.

The Solution

Step 1: Convert the Object to a String in EJS

To ensure that the JavaScript object is properly formatted as a string that can be parsed later, modify your EJS button code as follows:

[[See Video to Reveal this Text or Code Snippet]]

By using JSON.stringify(singleRecord), you convert the object into a JSON string format that can be transmitted correctly via the form submission.

Step 2: Parse the String back into an Object in Express

Once you receive the data on your Express server, the string needs to be parsed back into an object. Update your route to process the editBtn value correctly:

[[See Video to Reveal this Text or Code Snippet]]

With this adjustment, you can access any property of the object without hitting an undefined issue.

Conclusion

By ensuring that JavaScript objects are properly formatted and parsed when passing them between EJS and Express, you can seamlessly access the necessary object properties and enhance the functionality of your web application.

Follow these steps, and you’ll find that your interactions with objects become smoother and more reliable. Happy coding!