Resolving Error Parsing JSON in VBA with MSXML2.XMLHTTP Requests

A comprehensive guide to fixing the `Error Parsing JSON` issue in VBA while making POST requests using MSXML2.XMLHTTP. Learn to troubleshoot and validate your JSON request body.
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Resolving Error Parsing JSON in VBA with MSXML2.XMLHTTP Requests

When working with APIs in VBA, it's not uncommon to encounter issues, especially when dealing with JSON. One such problem that many developers face is the dreaded Error Parsing JSON message. In this post, we’ll take a closer look at how to identify and resolve this issue effectively using MSXML2.XMLHTTP.

The Problem: Understanding the Error

If you’ve been using VBA to retrieve a JSON response from an API, you might run into the following error message when attempting to execute your request:

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

This typically indicates that the response received from the server is not a valid JSON object that the parser expects. Most often, this occurs due to a malformed JSON request body, leading to an unsuccessful response from the server.

Why This Happens

Malformed JSON Request: The JSON you send in your request body may not be formatted correctly.

Improper Response Handling: Ignoring the HTTP status codes can lead to processing an invalid response.

Difference in Requests: The same request might work in Postman due to differences in how the request is constructed.

The Solution: Step-by-Step Fix

Here’s how you can properly construct your POST request in VBA to avoid the JSON parsing error.

Step 1: Check the Request Body Format

The first and foremost step is to ensure that your JSON request body is correctly formatted. In the provided VBA code, the issue stemmed from unquoted strings in the JSON structure.

Here's an example of what a correct JSON object should look like:

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

In VBA, you need to enclose keys and string values in double quotes, like so:

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

Step 2: Validate the Response

Always check the HTTP status returned by your request. This will help you understand whether your request was processed successfully or if there was an error.

Add this line after sending the request:

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

Step 3: Use Debugging Tools

If you continue to face issues after correcting your JSON and validating your response, consider using a tool like Fiddler to inspect the requests you're making. This can help you identify discrepancies between your VBA code and how the request is formed in tools like Postman.

Example Code Implementation

Here's a refined version of your VBA code that incorporates these suggestions:

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

Conclusion

By following these steps—ensuring proper JSON formatting, validating the HTTP response status, and using debugging tools—you can successfully troubleshoot the Error Parsing JSON issue in your VBA scripts. This approach not only fixes the immediate problem but also enhances your understanding of how to work with APIs effectively in VBA.

Remember, when dealing with APIs, always pay attention to the detail in your JSON structure, and don't hesitate to leverage debugging tools for clarity!