0

Looking for some input on the scripts below. Essentially I'm retrieving some json data with Invoke-WebRequest. I needed to export many of the properties to CSV. The data returned from Invoke-WebRequest is contained in an array: $devicedetails. This script works for outputting to CSV.

& {
    Foreach ($PC in $DeviceDetails)
    {     
        Foreach ($AppName in $PC.categories)
        {
            ForEach ($App in $AppName.apps)
            {
                   ForEach($Status in $App.health_status)
                   {
                        [pscustomobject] @{
                        "Device ID" = $PC.device_id
                        "Device Type" = $PC.device_type
                        "Device Name" = $PC.device_name
                        Nickname = $PC.nick_name
                        Last_Seen = $PC.last_seen
                        Compliance_Category_Status = $Appname.issue
                        Compliance_Category = $Appname.category_id 
                        Product_Name = $App.name
                        Product_Vendor = $App.vendor
                        Product_Version = $App.version
                        Product_Health_Item = $Status.status 
                        Product_Health_Status = $Status.issue 
                        }
                    }
            }
        }

    }
} | Export-CSV -PAth $Outfile -NoTypeInformation

Curious if this is the best way to output properties to CSV. Additionally, I now have the need to do some additional processes on the custom object I'm creating but if I assign a variable to that custom object as shown below, it takes several minutes to complete whereas just exporting to CSV takes 12-13 seconds. Why is the performance so bad?

$DeviceOutput= @()
    Foreach ($PC in $DeviceDetails)
    {     
        Foreach ($AppName in $PC.categories)
        {
            ForEach ($App in $AppName.apps)
            {
                   ForEach($Status in $App.health_status)
                   {
                        $DeviceOutput += [pscustomobject] @{
                        "Device ID" = $PC.device_id
                        "Device Type" = $PC.device_type
                        "Device Name" = $PC.device_name
                        "Nickname" = $PC.nick_name
                        Compliance_Category_Status = $Appname.issue
                        Compliance_Category = $Appname.category_id 
                        Product_Name = $App.name
                        Product_Vendor = $App.vendor
                        Product_Version = $App.version
                        Product_Health_Item = $Status.status 
                        Product_Health_Status = $Status.issue 
                        }
                    }
            }
        }

    }
YEMyslf
  • 407
  • 2
  • 12
  • 27
  • 3
    I would expect that outputting the objects directly (first example) rather than appending to an array (second example) would be faster. – Bill_Stewart Jul 14 '17 at 19:46
  • 1
    Yes much faster. So I suppose I'd be better off doing something like `$DeviceOutput = Foreach($PC in $Devicedetails)...` in order to assign the objects to a variable huh? – YEMyslf Jul 14 '17 at 20:05
  • Why do you need to assign the objects to a variable? – Bill_Stewart Jul 14 '17 at 20:18
  • Well its certainly possible that I've been overthinking things.:) I'd like to do some additional filtering on the new objects. So in my first example, I could just continue that pipeline to do my filter instead of exporting to csv. I also find it easier to work with the objects when they are assigned to a variable, but that's just my own inexperience. – YEMyslf Jul 14 '17 at 20:45
  • 2
    The performance hit is coming from `+=` since it has to recreate the array each time you do that. Instead do `$DeviceOutput = ForEach($PC in Devicedetails...` and remove the `$DeviceOutput += ` from the inner most loop. Also, learn to use the `.Where()` method to make an array of objects act like a single object, such as `$DeviceDetails.Where({$_.device_name -eq 'JacksLaptop'}).categories.apps.where({$_.Name -match 'Firefox'}).version` That should get you the version number of Firefox on Jack's laptop. – TheMadTechnician Jul 15 '17 at 01:04
  • Thanks @TheMadTechnician. Good tip on the `.Where()` method, I'll look into that. Either of you have thoughts around exporting the nested properties. Is the nested ForEach statement I'm using the best way to do this? – YEMyslf Jul 15 '17 at 17:01
  • 1
    It's the only way that I know of. CSV is limited since it can't handle nested arrays very well. – TheMadTechnician Jul 17 '17 at 17:33

0 Answers0