PSVirtualEnv

0.2.0

Functions/Get-VirtualEnvRequirement.ps1

# ===========================================================================
# Get-VirtualEnvRequirement.ps1 -------------------------------------------
# ===========================================================================

# validation --------------------------------------------------------------
# ---------------------------------------------------------------------------
Class ValidateVirtualEnv : System.Management.Automation.IValidateSetValuesGenerator {
    [String[]] GetValidValues() {
        return [String[]] ((Get-VirtualEnv | Select-Object -ExpandProperty Name) + "" + "python")
    }
}

# function ----------------------------------------------------------------
# ---------------------------------------------------------------------------
function Get-VirtualEnvRequirement {

    <#
    .DESCRIPTION
        Create the requirement file of a specific virtual environment.
     
    .PARAMETER Name
 
    .PARAMETER Python
 
    .PARAMETER All
 
    .PARAMETER Upgrade
 
    .OUTPUTS
        None.
    #>

    [CmdletBinding(PositionalBinding=$True)]

    [OutputType([Void])]

    Param(
        [ValidateSet([ValidateVirtualEnv])]
        [Parameter(Position=1, ValueFromPipeline=$True, HelpMessage="Name of the virtual environment.")]
        [System.String] $Name="",

        [Parameter(HelpMessage="If switch 'Python' is true, packages will be installed in default python distribution.")]
        [Switch] $Python,

        [Parameter(HelpMessage="If switch 'All' is true, the requirement file for all existing virtual environments will be generated.")]
        [Switch] $All,

        [Parameter(HelpMessage="If switch 'Upgrade' is true the requirement file is prepared for upgrading packages.")]
        [Switch] $Upgrade
    )

    Process {

        # check valide virtual environment
        if ($Name -and -not $Python) {
            if ($Name -eq "python"){
                $Python=$True
            }

            if (-not(Test-VirtualEnv -Name $Name)){
                Write-FormattedError -Message "The virtual environment '$($Name)' does not exist." -Module $PSVirtualEnv.Name -Space
                Get-VirtualEnv

                return
            }

            $virtualEnv = @{ Name = $Name }
        }

        # if default python distribution shall be modified set a placeholder
        if ($Python) {
            $virtualEnv = @{ Name = "python" }
        }

        # Get all existing virtual environments if 'Name' is not set
        if ($All) {
            $virtualEnv = Get-VirtualEnv
        }

        $virtualEnv | ForEach-Object {

            # get full path of requirement file
            $requirement_file = Get-VirtualEnvRequirementFile -Name $_.Name

            # get python distribution
            if ($Python) {
                $python_exe = Find-Python -Force
            }
            else {
                $python_exe = Get-VirtualPython -Name $_.Name
            }

            # create the requirement file of the specified virtual environment
            . $python_exe -m pip freeze > $requirement_file
            
            if ($Upgrade){
                $(Get-Content $requirement_file) -replace "==", ">=" | Out-File -FilePath $requirement_file
            }
        }
    }
}

# function ----------------------------------------------------------------
# ---------------------------------------------------------------------------
function Get-VirtualEnvRequirementFile {

    <#
    .DESCRIPTION
        Create the requirement file of a specific virtual environment.
     
    .PARAMETER Name
 
    .OUTPUTS
        System.String. Full path of virtual environment requirements file.
    #>

    [CmdletBinding(PositionalBinding=$True)]

    [OutputType([Void])]

    Param(
        [Parameter(Position=1, ValueFromPipeline=$True, Mandatory=$True, HelpMessage="Name of the virtual environment.")]
        [System.String] $Name
    )

    Process {

        return Join-Path -Path $PSVirtualEnv.RequireDir -ChildPath "$($Name)-requirements.txt" 
        
    }
}