Hello I've been working on the following for a while now. I can not get it to
add the new script method. any ideas are welcome


$ar = {
$a = [char[]] $this
[array]::reverse($a)
[string]::join('',$a)
}

$s = "One Two Three"
Add-Member -InputObject $s -MemberType ScriptMethod -Name reverse -Value $ar
$s.reverse()


Method invocation failed because [System.String] doesn't contain a method
named 'reverse'.
At D:.ps1:10 char:11
+ $s.reverse( <<<< )

A synthetic member is added to a [psObject], $s is [String]. By casting the initial assignment of $s to [psObject] the ScriptMethod is added to $s.
Another way -'the best practice' way- is to create a [psObject] from $s while adding the synthetic member, need to use Add-Member's -PassThru parameter:

# eliminate $s
rv s -ea 0
$ar = {
$a = [char[]] $this
[array]::reverse($a)
[string]::join('',$a)
}

# cast $s to [psObject]
[psObject]$s = "One Two Three"
Add-Member -InputObject $s -MemberType ScriptMethod -Name reverse -Value $ar
$s.reverse()


# or...
# 'best practice'
# eliminate $s
rv s -ea 0
$ar = {
$a = [char[]] $this
[array]::reverse($a)
[string]::join('',$a)
}

$s = "One Two Three"
# create a psObject from $s with a synthetic member
$s = Add-Member -InputObject $s -MemberType ScriptMethod -Name reverse -Value $ar -passThru
$s.reverse()

--
Kiron

Got it. Thanks for the info.

Best Regards,
B
"Kiron" <Kiron@xxxxxx> wrote in message
news:5F946FBE-0272-44CB-A0AD-C012BE929CB4@xxxxxx
A synthetic member is added to a [psObject], $s is [String]. By casting the
initial assignment of $s to [psObject] the ScriptMethod is added to $s.
Another way -'the best practice' way- is to create a [psObject] from $s
while adding the synthetic member, need to use Add-Member's -PassThru
parameter:

# eliminate $s
rv s -ea 0
$ar = {
$a = [char[]] $this
[array]::reverse($a)
[string]::join('',$a)
}

# cast $s to [psObject]
[psObject]$s = "One Two Three"
Add-Member -InputObject $s -MemberType ScriptMethod -Name reverse -Value $ar
$s.reverse()


# or...
# 'best practice'
# eliminate $s
rv s -ea 0
$ar = {
$a = [char[]] $this
[array]::reverse($a)
[string]::join('',$a)
}

$s = "One Two Three"
# create a psObject from $s with a synthetic member
$s = Add-Member -InputObject $s -MemberType ScriptMethod -Name
reverse -Value $ar -passThru
$s.reverse()

--
Kiron

Glad to help.

--
Kiron

Another approach, if you're keen to add your method to the string type, is
to add a chunk of xml code to the file

C:\WINDOWS\system32\WindowsPowerShell\v1.0\types.ps1xml

You could then use your Reverse method for any string within a Powershell
session or script

PS (1) > $a="apple"
PS (2) > $a.Reverse()
elppa
PS (3) >



#-------------------------------------------------
<Type>
<Name>System.String</Name>
<Members>
<ScriptMethod>
<Name>Reverse</Name>
<Script>
$a = [char[]] $this
[array]::reverse($a)
[string]::join('',$a)
</Script>
</ScriptMethod>
</Members>
</Type>
#-------------------------------------------------

NB You'd place the code at the end of another <type> ....</type> block.

--
Jon

You can extend $s and intreduce new members even though it's not a psObject.
After all, everything in PowerShell is object based

PS 1> $s = "llehSrewoP"

PS 2> $ar = {

>> $o=$ofs; $ofs=""
>> "$($this[$this.length..0])"
>> $ofs=$o
>> }
>>

PS 3> $s = $s | Add-Member -pass ScriptMethod reverse $ar

PS 4> $s | gm r*


TypeName: System.String

Name MemberType Definition
---- ---------- ----------
(...)
reverse ScriptMethod System.Object reverse();


PS 5> $s.reverse()
PowerShell


-----
Shay Levi
$cript Fanatic
http://scriptolog.blogspot.com

> A synthetic member is added to a [psObject], $s is [String]. By
> casting the initial assignment of $s to [psObject] the ScriptMethod is
> added to $s.
>
> Another way -'the best practice' way- is to create a [psObject] from
> $s while adding the synthetic member, need to use Add-Member's
> -PassThru parameter:
>
> # eliminate $s
> rv s -ea 0
> $ar = {
> $a = [char[]] $this
> [array]::reverse($a)
> [string]::join('',$a)
> }
> # cast $s to [psObject]
> [psObject]$s = "One Two Three"
> Add-Member -InputObject $s -MemberType ScriptMethod -Name reverse
> -Value $ar
> $s.reverse()
> # or...
> # 'best practice'
> # eliminate $s
> rv s -ea 0
> $ar = {
> $a = [char[]] $this
> [array]::reverse($a)
> [string]::join('',$a)
> }
> $s = "One Two Three"
> # create a psObject from $s with a synthetic member
> $s = Add-Member -InputObject $s -MemberType ScriptMethod -Name reverse
> -Value $ar -passThru
> $s.reverse()

> ...add a chunk of xml code to the file C:\WINDOWS\system32\WindowsPowerShell\v1.0\types.ps1xml

It's better/safer to create a new ps1xml file and extend the type through the Update-TypeData Cmdlet.

--
Kiron

"Kiron" <Kiron@xxxxxx> wrote in message
news:C99C483B-83A0-4D3D-8243-69A2DB51ED89@xxxxxx

>> ...add a chunk of xml code to the file
>> C:\WINDOWS\system32\WindowsPowerShell\v1.0\types.ps1xml

>
> It's better/safer to create a new ps1xml file and extend the type through
> the Update-TypeData Cmdlet.
>

Yep, you're right - that's a better way of doing it. Keeping it in a
separate file also allows you to easily see what changes have been made,
should you wish to reverse them (please excuse the pun).

I tried doing something similar before, by adding a types.ps1xml in a
directory included in path environment variable, thinking that it would be
picked up automatically. It wasn't. So I suppose you need to explicitly add
it using Update-TypeData

Good tip. Thanks Kiron.

--
Jon

Doh! I was just going to say that.

--
Keith
"Kiron" <Kiron@xxxxxx> wrote in message news:CB84B2FD-1DD3-47B9-9905-1615D31AA27C@xxxxxx


By the way, the ScriptBlock could be simplified, no need to 'reset' $ofs because its only changed in the ScriptMethod's scope:
$ar = {
$ofs=""
"$($this[-1..-$this.length])"
}

It wouldn't surprise me if Microsoft just plain overwrote those files with V2. At the moment, the v2 CTP installs into the same directory as V1.

--
Keith
"Kiron" <Kiron@xxxxxx> wrote in message news:C99C483B-83A0-4D3D-8243-69A2DB51ED89@xxxxxx

> ...add a chunk of xml code to the file C:\WINDOWS\system32\WindowsPowerShell\v1.0\types.ps1xml

It's better/safer to create a new ps1xml file and extend the type through the Update-TypeData Cmdlet.

--
Kiron