Why using JSON Files in PowerShell is neat
In the last couple of weeks I worked a lot with PowerShell and text-based input files to separate code and data. Since my beginnings in PowerShell I always used XML-based files to cover the separation.
The task I am currently working on is very complex and the designed XML data structure is not readable in an editor like notepad++ anymore. Due to this I had to search for an alternative file format. Some colleagues of mine are currently involved in Microsoft Azure projects and I heard about the JSON file format from them. JSON stands for JavaScript Object Notation (http://en.wikipedia.org/wiki/JSON) and is a well-known format within Azure. JSON provides a set of supported data types you can use directly (like Number, String, Boolean, Array, …) what is very handy and easy to adopt.
During my research and testing I found a lot of helpful websites and blogs covering JSON handling within PowerShell. Within this article I want to share some of my experiences with you.
Example
First, let’s have a look at a simple JSON file:
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{ "Name": "Timm-TestCatalog-002", "Description": "Timm-TestCatalog-002", "AllocationType": "Random", "ProvisioningType": "Manual", "SessionSupport": "MultiSession", "PersistUserChanges": "OnLocal", "ProvisioningSchemeId": "", "CatalogKind": "", "PvsForVM": "", "IsRemotePC": false, "MachinesArePhysical": true, "MinimumFunctionalLevel": "L7_6", "PvsAddress": "", "PvsDomain": "", "RemotePCHypervisorConnectionUid": "", "Scope": [ "sepago-Admins", "sepago-Helpdesk" ]} |
As you can see within this example – description of a XenDesktop Catalog – I use different data types (String, Boolean, Array).
Now I can easily import this JSON file into PowerShell with the following command one-liner:
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$JSONFile = ConvertFrom-Json "$(get-content $(Join-Path $env:temp "File.json"))" |
Within the PowerShell $JSONFile is a PSCustomObject:
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$JSONFile.gettype()IsPublic IsSerial Name BaseType-------- -------- ---- --------True False PSCustomObject System.Object |
And the NoteProperty “IsRemotePC” is a Boolean – as expected:
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$JSONFile.isRemotePC.GetType() IsPublic IsSerial Name BaseType -------- -------- ---- -------- True True Boolean System.ValueType |
Now I can use these information to create a new catalog within XenDesktop. To do this, transform the PSCustomObject into a Hash Table, which can be provided directly to the Citrix XenDesktop cmdlet (see my previous post covering parameters and Hash Tables):
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$HashTable = @{}$JSONFile | get-member -MemberType NoteProperty | Where-Object{ -not [string]::IsNullOrEmpty($JSONFile."$($_.name)")} | ForEach-Object {$HashTable.add($_.name,$ JSONFile."$($_.name)")}$BrokerCatalog = New-BrokerCatalog @HashTable |
Conclusion
As you see working with JSON files within PowerShell is very neat. The example I shared with you is not that difficult, sure. Within my PowerShell scripts I am currently working with JSON file with more than 200 lines and multiple sections resulting in different Hash Tables. I will share more examples with you in one of my following articles.