Attributes are, well, attributes of an object.
Attributes allow us to add additional information to something in a somewhat standard way.
In PowerShell, there are several places you can provide attributes:
All Script Blocks in PowerShell can have attributes.
They can be placed above the param block, though there has to actually be a parameter block.
{
[Reflection.AssemblyMetadata("SomeKey","SomeValue")]
param()
}.Attributes
Since PowerShell functions are script blocks with names, we can add an attribute to a function in the same way.
function ACommandWithAttributes {
[Reflection.AssemblyMetadata("SomeKey","SomeValue")]
param()
}
(Get-Command ACommandWithAttributes).ScriptBlock.Attributes
PowerShell Parameters use attributes quite a bit.
In fact, the thing that separates a simple parameter from a smart one is the presence of a [Parameter] attribute.
function AFunctionWithMandatoryParameters {
param(
[Parameter(Mandatory)]
$ThisParameterIsMandatory
)
}