Resolving undefined Returns in Angular Promises Between Components

Discover how to fix the issue of `undefined` returns in Angular when working with async methods across components. Learn best practices for handling Promises effectively!
---

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: Angular Promise returns undefined in another component

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
Understanding the undefined Return from Angular Promises

In the world of Angular development, working with asynchronous data can sometimes lead to frustrating challenges. One common issue developers face is when a Promise unexpectedly returns undefined. This can occur when making calls between components, as demonstrated in the scenario below.

The Problem

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

Later, when trying to log the result in the DisplaySVG() method of another component:

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

Despite the method functioning properly, the result is still coming back as undefined.

Analyzing the Issue

The key to resolving this issue lies in the fact that the Download() method does not return anything. In JavaScript, if a function does not have an explicit return statement, it defaults to returning undefined. Therefore, when you call the method from your viewCarsComponent and try to log its output, you are indeed logging the undefined result.

The Solution

To fix this, you'll need to ensure that your Download() method returns the expected data. Here's how to do it:

Step 1: Return the SVG Data

Here’s how you can adjust your Download method to return the array of SVGs, which is likely what you're after:

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

Step 2: Return Only the SVG Properties (if needed)

If you only need the SVG properties from the objects you're working with, you can create a new array that consists solely of those properties. Update the method like so:

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

Conclusion

By making these minor adjustments to your Download() method, you should be able to retrieve the desired output in your viewCarsComponent. Remember that whenever you're dealing with asynchronous functions in JavaScript, especially in frameworks like Angular, ensuring your methods return the correct values is crucial for maintaining functional code and debugging effectively.

Now you have the necessary steps to avoid returning undefined from your Promises in Angular. Happy coding!