Visual Basic for Applications:
Working with YAML

How to:

Working with YAML in VBA requires understanding how to parse and convert YAML into a format that VBA can easily manipulate, usually dictionaries or collections. Unfortunately, VBA does not natively support YAML parsing or serialization. However, you can use a combination of JSON conversion tools and dictionary objects to work with YAML data, considering YAML’s close relation to JSON.

First, convert your YAML data to JSON using an online converter or a YAML-to-JSON conversion tool within your development environment. Once converted, you can use the following example to parse JSON in VBA, noting that this approach indirectly allows you to work with YAML:

' Add reference to Microsoft Scripting Runtime for Dictionary
' Add reference to Microsoft XML, v6.0 for JSON parsing

Sub ParseYAMLAsJSON()
    Dim jsonText As String
    jsonText = "{""name"": ""John Doe"", ""age"": 30}" ' This is JSON converted from YAML
    
    ' Assuming you have a JSON parser function
    Dim parsedData As Dictionary
    Set parsedData = JsonParser(jsonText)
    
    Debug.Print "Name: " & parsedData("name")
    Debug.Print "Age: " & parsedData("age")
End Sub

Function JsonParser(ByVal jsonText As String) As Dictionary
    ' Placeholder for JSON parsing logic - you might use an external library here
    Set JsonParser = New Dictionary
    JsonParser.Add "name", "John Doe"
    JsonParser.Add "age", 30
End Function

In this example, the JsonParser function is a stand-in for where you’d parse the JSON. Various libraries are available to help with JSON parsing, as direct YAML parsing libraries for VBA are scarce.

Deep Dive

The absence of direct YAML handling in VBA can be attributed to its age and the environment it was built for, which was not initially designed with modern data serialization formats in mind. YAML itself emerged as a popular configuration and serialization format in the early 2000s, dovetailing with the advent of applications requiring more human-friendly configuration files.

Programmers typically leverage external tools or libraries to bridge the gap between VBA and YAML. This often involves converting YAML to JSON, as shown, due to the JSON support available through various libraries and the similarity between JSON and YAML in terms of structure and purpose.

While working with YAML directly in VBA showcases the language’s flexibility, it’s worth noting that other programming environments (e.g., Python or JavaScript) provide more native and seamless support for YAML. These alternatives might be better suited for projects heavily reliant on YAML for configuration or data serialization. Nonetheless, for those committed to or requiring VBA, the indirect method through JSON conversion remains a viable and useful approach to manage and manipulate YAML data.