Handling Image Loading with JavaScript Promises

daca-github - May 14 '23 - - Dev Community

In a recent project I was working on, I encountered an issue with image loading that caused quite a bit of frustration. The project was a movie search application that fetched data from the OMDB API, which includes movie poster URLs. The issue was that some movies didn't have a poster image, and this resulted in broken image links in my application. It was unsightly and unprofessional. So, I set out to find a solution.

The Problem:

The OMDB API returns a URL for the movie poster image, even if there isn't an image available. This URL, when used as an src attribute in an img tag, results in a broken image link. The challenge was figuring out how to validate the image URL before using it in the img tag.

The Solution:

The solution I found leverages JavaScript Promises and the Image object to pre-load the image before displaying it. If the image loads successfully, the function resolves with the URL, which can be used as the src for the img tag. If the image fails to load, the function resolves with a placeholder image URL.

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Using the Function:

This function can be used with async/await to load images asynchronously, ensuring that an image or placeholder is always displayed. Here's an example of how to use it:

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Conclusion:

This solution elegantly handles the issue of broken image links by ensuring that every movie has a poster image, whether it's the actual poster or a placeholder. By using JavaScript Promises and the Image object, it checks if the image URL is valid before using it. This level of validation greatly improves the user experience and the overall quality of the application.

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