Solving Dynamic Key Issues with JOLT for JSON Array Transformation

Learn how to effectively extract and concatenate dynamic key messages from JSON using JOLT transformation.
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Solving Dynamic Key Issues with JOLT for JSON Array Transformation

In the world of web services and APIs, dealing with JSON data is a common task. Often, you may encounter situations where the structure of the JSON data includes dynamic keys that need special handling. For instance, you might want to extract error messages from various entries in such a JSON structure. This guide will guide you through the process of achieving this using JOLT, a JSON transformation library.

The Problem

Imagine you receive a JSON response from a web service that contains messages with dynamic keys — keys that can vary in name depending on the input. Here’s a simplified version of how the JSON might look:

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

In this scenario, the goal is to extract all the error messages from the dynamic keys in the data object and format them into a single concatenated string for an error message.

The Solution: Using JOLT Transformations

To achieve this transformation, we can use a combination of JOLT operations: shift and modify-overwrite-beta with a join function. Let’s break it down step by step.

Step 1: Shift the Structure

The first step is to create a specification that tells JOLT how to restructure the original JSON. This is done using the shift operation. Here’s how it looks:

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

Step 2: Join the Messages

Next, we need to concatenate the messages into a single string using the modify-overwrite-beta operation. This allows us to group the dynamic error messages into one string, separated by a delimiter (like a pipe |). Here’s the specification for this step:

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

Putting It All Together

Now that we have both transformation steps, here’s the complete JOLT spec we’d use:

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

Resulting JSON Output

When you apply the above JOLT transformations to our initial JSON structure, it will generate the following output:

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

Conclusion

By utilizing JOLT’s powerful transformation capabilities, you can efficiently deal with dynamic keys in JSON responses, allowing you to extract and concatenate data seamlessly. This approach not only simplifies your code but also makes the handling of dynamic and unpredictable JSON structures much more manageable.

Now, whenever you face a similar issue with dynamic keys, you have an effective solution at hand!