Select some properties of an array of object and rename it-CodePudding

I have an array of objects, which have the property of p1, p2, p3, p4.

$objectArray = [PSCustomObject]@{
    p1 = "Value1"; p2 = "Value2"; p3 = "Value3"; p4 = "Value4"
},[PSCustomObject]@{
    p1 = "Value5"; p2 = "Value6"; p3 = "Value7"; p4 = "Value8"
}

And I have a property-name-mapping hashtable, for example

$propertyReplacements = @{
    "p1" = "x1"
    "p2" = "y1"
}

How to select only the properties which exist in the keys of hash table $propertyReplacements; and rename the property name to the values in the hash table?

The result will be

[PSCustomObject]@{
    x1 = "Value1"; y1 = "Value2";
},[PSCustomObject]@{
    x1 = "Value5"; y1 = "Value6";
}

The properties filtering can be

$objectArray | select -Property @($propertyReplacements.Keys) |
....

CodePudding user response：

The following uses an ordered dictionary and casting [pscustomobject] to create new objects, I really don't think Select-Object is the proper tool for this.

# use a temporary ordered dictionary
$tmp = [ordered]@{}
# enumerate each object
foreach($obj in $objectArray) {
    # store the PSMemberInfoIntegratingCollection for later access
    $properties = $obj.PSObject.Properties
    # enumerate the hash keys
    foreach($key in $propertyReplacements.Keys) {
        # if the hash key exists as property Name in this object
        if($prop = $properties.Item($key)) {
            # create a new property Name using the Value of the hashtable
            # and keep the current Value of the value
            $tmp[$propertyReplacements[$prop.Name]] = $prop.Value
        }
    }
    # create a new object casting this type accelerator
    [pscustomobject] $tmp
    # and clear the dictionary for the next object
    $tmp.Clear()
}

CodePudding user response：

Here is another solution

foreach($k in $propertyReplacements.Keys) {
    if ($k -ne $propertyReplacements.$k) {
        $objectArray = $objectArray | select *,{n=$propertyReplacements.$k; $e={$_.$k}}
        $objectArray = $objectArray | select -ExcludeProperty $k
    }
}
# $objectArray has updated property names now