Moving from CSV to XML Part 4

Over the last several articles I’ve been documenting my journey of transitioning from CSV files to XML. I encourage you to get caught up on past articles otherwise today’s content won’t make much sense. My ultimate goal from the beginning was to come up with a tool to convert or transform a CSV file into an XML file, complete with type information so that I can import the XML back into PowerShell as typed objects. Let’s walk through the final steps.

First, here’s the CSV test file I’ve been working with.

I think you can look at that and figure out what type is necessary for each property if I import the CSV file. In fact, I’m going to import it with the Import-MyCSV function I showed you earlier.

I will get prompted to provide a type for each property.

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But everything is typed.

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Now that I am satisfied with the data, I can convert it to an XML document.

And for the sake of my demonstration, I’ll use another of the functions I showed in an earlier article to rename the Objects and Object nodes to something more meaningful.

Well, perhaps not meaningful but at least different. Once renamed I can save the XML document to disk.

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If I want to complete the transformation I can re-import the XML using my Import-MyXML function.

Perfect. Of course, I don’t’ want to have to manually type the few steps to convert a CSV file to XML so I wrote a function. Because my Convert-CsvToXml function relies on the other new commands I’ve developed, I copied all of the functions into a single script file and created a PowerShell module I call CsvXmlTools.psm1. Here’s the entire module.


You should create a folder called CsvXmlTools under C:\Users\<YOU>\Documents\WindowsPowerShell\Modules and place the .psm1 file in it. If you decide to call it something else, just remember the folder name must match the name of the .psm1 file. I did not create a manifest but you are welcome to.

The Convert-CSVtoXML function brings everything together, including the option to rename nodes.

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The NewCollection parameter reflects the top level or Objects node. The NewItem parameter is used to rename Object to something else. Because I’m running this end to end I know that the interim XML will be using Objects and Object.

Now, I can simply run my Convert-CsvToXml function (assuming the module is in a known location).

I will be prompted to provide a type name for each property.

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You don’t need to enter the type as System.String. Just ‘String’ will suffice because my Import-MyCSV function is now using the –Regex option for the Switch statement.

$property = $_.key
write-Verbose “$property = $($CSV.$property)”
#only process if there is a value
if ($CSV.$property) {
Switch -Regex ($_.Value) {
“datetime” { $value = [convert]::ToDateTime($CSV.$property) }
“decimal” { $value = [convert]::ToDecimal($CSV.$property) }
“char” { $value = [convert]::ToChar($CSV.$property) }
“string” { $value = [convert]::ToString($CSV.$property) }
“int” { $value = [convert]::ToInt32($CSV.$property) }
“int16” { $value = [convert]::ToInt16($CSV.$property) }
“int32” { $value = [convert]::ToInt32($CSV.$property) }
“int64” { $value = [convert]::ToInt64($CSV.$property) }
“uint32” { $value = [convert]::ToUInt32($CSV.$property) }
“uint64” { $value = [convert]::ToUInt64($CSV.$property) }
“boolean” { $value = [convert]::ToBoolean($CSV.$property) }
“double” { $value = [convert]::ToDouble($CSV.$property) }
Default { $value = $CSV.$property }
} #switch
} #if there is a property value
else {
#set the value to null
$Value = $Null
#add to the hashtable
That one line command converted the original CSV file into this XML:

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As far as I’m concerned this is mission accomplished. I hope you found this a useful experience and maybe even learned a thing or two about using CSV or XML files in PowerShell. Comments are always welcome.