Template

Code generation by using text templates. A template specifies a text template with placeholders for data to be extracted from models.

The 'Template' module offers these features:

• Text replacement, simple or by regex or regex with MatchEvaluator (Scriptblock)
• File inclusion
• Directive to run embedded scripts
• Conditionnal directive (#Define & #Undef)
• Removal and uncomment directive

Install

$PSGalleryPublishUri = 'https://www.myget.org/F/ottomatt/api/v2/package'
$PSGallerySourceUri = 'https://www.myget.org/F/ottomatt/api/v2'
Register-PSRepository -Name OttoMatt -SourceLocation $PSGallerySourceUri -PublishLocation $PSGalleryPublishUri #-InstallationPolicy Trusted

Install-Module Template -Repository OttoMatt

Principle

A template is a file that serves as a starting point for a new document. The 'Template' module, allow to insert directives, as a comment, inside the source code. For example :

    Write-Debug 'Test' #<%REMOVE%>

In this case, the presence of this directive does not require to transform the source code before to execute it.

For this example, the directives require a transformation :

Import-Module Template
 #Initialize-TemplateModule.ps1 create the hashtable $TemplateDefaultSettings

$File='C:\temp\Code.PS1'
@'
Write 'Text before the directive'
<#%ScriptBlock%
    #<DEFINE %V5%>
        . .\Convert-ObjectToClass.ps1
        #Class PS >= v5
        Convert-ObjectToClass -InputObject (Get-Process|Select Name,VirtualMemorySize -First 1)
    #<UNDEF %V5%>

    #<DEFINE %V3%>
        . .\New-PSCustomObjectFunction.ps1
        #PSCustomObject >= v3
        New-PSCustomObjectFunction -Noun ProcessLight -Parameters Name,VirtualMemorySize -AsFunction
    #<UNDEF %V3%>
#>
Write 'Text after the directive'
'@ > $File

The following script transform the content:

[string[]]$Lines=Get-Content -Path $File  -ReadCount 0 -Encoding UTF8
  #Edit-Template need an ARRAY of string
$Result=,$Lines|Edit-Template -ConditionnalsKeyWord  "V5"|
 Edit-Template -Clean
$Result

to :

Write 'Text before the directive'
<#%ScriptBlock%

        . .\New-PSCustomObjectFunction.ps1
        #PSCustomObject >= v3
        New-PSCustomObjectFunction -Noun ProcessLight -Parameters Name,VirtualMemorySize -File
#>
Write 'Text after the directive'

The text between the directive #<DEFINE %V5%> and #<UNDEF %V5%> is deleted. The parameter -Clean remove the remaining directives inside the text.

The second step, invoke the script to generate text :

 #Edit-String need a string
$ofs="`r`n"
"$Result"|
 Edit-String -Setting  $TemplateDefaultSettings

The final source code :

Write 'Text before the directive'
Function New-ProcessLight{
param(
         [Parameter(Mandatory=$True,position=0)]
        $Name,
         [Parameter(Mandatory=$True,position=1)]
        $VirtualMemorySize
)

  [pscustomobject]@{
    PSTypeName='ProcessLight';
    Name=$Name;
    VirtualMemorySize=$VirtualMemorySize;
   }


}# New-ProcessLight
Write 'Text after the directive'

With this script :

Get-Content -Path $File  -ReadCount 0 -Encoding UTF8|
 Edit-Template -ConditionnalsKeyWord  "V3"|
 Edit-Template -Clean|
 Out-string|
 Edit-String -Hashtable $TemplateDefaultSettings

The result text is :

Write 'Text before the directive'
class ProcessLight
{
        [string] $Name;
        [int] $VirtualMemorySize;

        ProcessLight([System.Diagnostics.Process] $Process) {
                $this.Name = $Process.Name
                $this.VirtualMemorySize = $Process.VirtualMemorySize

        }
} #ProcessLight
Write 'Text after the directive'