CODEWITHSUNDEEP
c#powershell
Vijay
Vijay

Reputation: 167

Custom Powershell Provider implementation

I want to create a PowerShell Provider that will work like a directory structure. The root is a web address that returns a text file. This file has a list of items. When each of these items is appended to the end of the original web address, I get another file with another list of items. This goes on recursively until the file does not return any item. So the structure is like:

root: 1.2.3.4/test/     -> returns file0
file0: item1, item2, item3

1.2.3.4/test/item1      -> returns file1
1.2.3.4/test/item2      -> returns file2
1.2.3.4/test/item3      -> returns file3

file1: item4, item5
file2: item6
file3: <empty>

Since I want to create a navigation like structure, I extended the NavigationCmdletProvider

public class TESTProvider : NavigationCmdletProvider

I am able to create the new PSDrive as follows:

PS c:\> New-PSDrive -Name dr1 -PSProvider TestProvider -Root http://1.2.3.4/v1

Name           Used (GB)     Free (GB) Provider     Root                                            CurrentLocation
----           ---------     --------- --------      -------------------
dr1                                    TestProvider  http://1.2.3.4/v1

But when I 'cd' to that drive, I get an error:

PS c:\> cd dr1:

cd : Cannot find path 'dr1:\' because it does not exist.
At line:1 char:1
+ cd dr1:
+ ~~~~~~~~
    + CategoryInfo          : ObjectNotFound: (dr1:\:String) [Set-Location], ItemNotFoundException
    + FullyQualifiedErrorId : PathNotFound,Microsoft.PowerShell.Commands.SetLocationCommand

What method do I have to implement/override to show the prompt as PS dr1:> when I do cd dr1:? (After this I understand that I will have to override GetChildItems(string path, bool recurse) to get item1, item2, item3 listed.)

Upvotes: 4

Views: 783

Answers (1)

John Koerner
John Koerner

Reputation: 38077

I have found that implementing IsValidPath, ItemExists, IsItemContainer, and GetChildren get you to a working state. This is what I usually start with when I am implementing a navigation provider:

[CmdletProvider("MyPowerShellProvider", ProviderCapabilities.None)]
public class MyPowerShellProvider : NavigationCmdletProvider
{

    protected override bool IsValidPath(string path)
    {
        return true;
    }

    protected override Collection<PSDriveInfo> InitializeDefaultDrives()
    {
        PSDriveInfo drive = new PSDriveInfo("MyDrive", this.ProviderInfo, "", "", null);
        Collection<PSDriveInfo> drives = new Collection<PSDriveInfo>() {drive};
        return drives;
    }

    protected override bool ItemExists(string path)
    {
        return true;
    }

    protected override bool IsItemContainer(string path)
    {
        return true;
    }

    protected override void GetChildItems(string path, bool recurse)
    {
        WriteItemObject("Hello", "Hello", true);
    }
}

Upvotes: 3

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