Functions/Install-IisVirtualDirectory.ps1

# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

function Install-CIisVirtualDirectory
{
    <#
    .SYNOPSIS
    Installs a virtual directory.
 
    .DESCRIPTION
    The `Install-CIisVirtualDirectory` function creates a virtual directory under website `SiteName` at `/VirtualPath`, serving files out of `PhysicalPath`. If a virtual directory at `VirtualPath` already exists, it is updated in palce. (Before Carbon 2.0, the virtual directory was deleted before installation.)
 
    Beginning with Carbon 2.0.1, this function is available only if IIS is installed.
 
    .EXAMPLE
    Install-CIisVirtualDirectory -SiteName 'Peanuts' -VirtualPath 'DogHouse' -PhysicalPath C:\Peanuts\Doghouse
 
    Creates a /DogHouse virtual directory, which serves files from the C:\Peanuts\Doghouse directory. If the Peanuts website responds to hostname `peanuts.com`, the virtual directory is accessible at `peanuts.com/DogHouse`.
 
    .EXAMPLE
    Install-CIisVirtualDirectory -SiteName 'Peanuts' -VirtualPath 'Brown/Snoopy/DogHouse' -PhysicalPath C:\Peanuts\DogHouse
 
    Creates a DogHouse virtual directory under the `Peanuts` website at `/Brown/Snoopy/DogHouse` serving files out of the `C:\Peanuts\DogHouse` directory. If the Peanuts website responds to hostname `peanuts.com`, the virtual directory is accessible at `peanuts.com/Brown/Snoopy/DogHouse`.
    #>

    [CmdletBinding()]
    param(
        [Parameter(Mandatory=$true)]
        [string]
        # The site where the virtual directory should be created.
        $SiteName,
        
        [Parameter(Mandatory=$true)]
        [Alias('Name')]
        [string]
        # The name of the virtual directory. This can contain multiple directory segments for virtual directories not at the root of the website, e.g. First/Second/VirtualDirectory.
        $VirtualPath,
        
        [Parameter(Mandatory=$true)]
        [Alias('Path')]
        [string]
        # The file system path to the virtual directory.
        $PhysicalPath,

        [Switch]
        # Deletes the virttual directory before installation, if it exists. Preserves default beheaviro in Carbon before 2.0.
        #
        # *Does not* delete custom configuration for the virtual directory, just the virtual directory. If you've customized the location of the virtual directory, those customizations will remain in place.
        #
        # The `Force` switch is new in Carbon 2.0.
        $Force
    )
    
    Set-StrictMode -Version 'Latest'

    Use-CallerPreference -Cmdlet $PSCmdlet -Session $ExecutionContext.SessionState

    $site = Get-CIisWebsite -Name $SiteName
    [Microsoft.Web.Administration.Application]$rootApp = $site.Applications | Where-Object { $_.Path -eq '/' }
    if( -not $rootApp )
    {
        Write-Error ('Default website application not found.')
        return
    }

    $PhysicalPath = Resolve-CFullPath -Path $PhysicalPath

    $VirtualPath = $VirtualPath.Trim('/')
    $VirtualPath = '/{0}' -f $VirtualPath

    $vdir = $rootApp.VirtualDirectories | Where-Object { $_.Path -eq $VirtualPath }
    if( $Force -and $vdir )
    {
        Write-IisVerbose $SiteName -VirtualPath $VirtualPath 'REMOVE' '' ''
        $rootApp.VirtualDirectories.Remove($vdir)
        $site.CommitChanges()
        $vdir = $null

        $site = Get-CIisWebsite -Name $SiteName
        $rootApp = $site.Applications | Where-Object { $_.Path -eq '/' }
    }

    $modified = $false

    if( -not $vdir )
    {
        [Microsoft.Web.Administration.ConfigurationElementCollection]$vdirs = $rootApp.GetCollection()
        $vdir = $vdirs.CreateElement('virtualDirectory')
        Write-IisVerbose $SiteName -VirtualPath $VirtualPath 'VirtualPath' '' $VirtualPath
        $vdir['path'] = $VirtualPath
        [void]$vdirs.Add( $vdir )
        $modified = $true
    }

    if( $vdir['physicalPath'] -ne $PhysicalPath )
    {
        Write-IisVerbose $SiteName -VirtualPath $VirtualPath 'PhysicalPath' $vdir['physicalPath'] $PhysicalPath
        $vdir['physicalPath'] = $PhysicalPath
        $modified = $true
    }

    if( $modified )
    {
        $site.CommitChanges()
    }
}