Functions/Get-FilteredCsvString.ps1
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<#
.SYNOPSIS This function filters a CSV string, keeping rows which have $true or the specified values for the specified columns. #> function Get-FilteredCsvString { [CmdletBinding()] [OutputType([Object[]])] param ( # The CSV string to filter. [Parameter(Mandatory=$true)] [ValidateNotNullOrEmpty()] [String]$csv, # The columns used to filter the CSV string. [Parameter(Mandatory=$false)] [ValidateNotNull()] [String[]]$columns, # The column values used to filter the CSV string. [Parameter(Mandatory=$false)] [PSObject[]]$columnValues, # Select if the filtering is 'and' or 'or'. # If the filtering is 'and', all the specified columns must match the column values [Parameter(Mandatory=$false)] [ValidateSet("and", "or")] [String]$filtering = "and" ) # Convert columns and column values to array $columns = ConvertTo-Array $columns $columnValues = ConvertTo-Array $columnValues # Provide default for column values used for filtering # Default is that value must be $true for the row to be kept if ($columns.count -gt 0 -and $columnValues.count -eq 0) { $columnValues = $columns | ForEach-Object { $true } } # Verify column values if ($columns.count -ne $columnValues.count) { Write-Error "Number of columns ($($columns.count)) and number of column values ($($columnValues.count)) provided are not the same." return $null } # Convert the CSV string to CSV object $csvObject = ConvertTo-CsvObject $csv if (!$csvObject) { Write-Error "Failed to convert input CSV string to CSV object." return $null } # Filter the CSV by the column names if ($columns) { $columnNames = ConvertTo-Array ($columns.Split(",") | ForEach-Object { $_.Trim() }) # Run through each entry in the CSV $csvObject = $csvObject | ForEach-Object -Process { $csvEntry = $_ # Perform a count of the number of properties which are true $filterResult = @() for ($i = 0; $i -lt $columns.count; ++$i) { if ($csvEntry.($columns[$i]) -eq $columnValues[$i]) { $filterResult += $true } } # All the properties are true, the entry stays if ($filtering -eq "and" -and $filterResult.length -eq $columns.count) { $csvEntry } # At least one property is true, the entry stays elseif ($filtering -eq "or" -and $filterResult.length -gt 0) { $csvEntry } } } # No items left after filtering if (!$csvObject) { return $null } # Return the result as a CSV string $csvString = ConvertTo-CsvString $csvObject if ([String]::IsNullOrWhiteSpace($csvString)) { Write-Error "Failed to convert CSV object to CSV string." return $null } return $csvString } |