Download #MVA Content with PowerShell

So I'm starting to go through some of the content on Microsoft Virtual Academy but I don't have time to do this when I'm by a good internet connection and at the same time don't have time when by the good internet connection to run though all the content I need to download it to watch in my spare time.

Enter PowerShell

As with any scenario like this you turn to code, I use to create all these types of functionality in C# apps but have recently decided that it's too easy in C# and wanted to learn PowerShell better so now these are all PowerShell scripts.

The Code

There are 2 files:

Remove-InvalidFileNameChars.ps1

#source - http://gallery.technet.microsoft.com/scriptcenter/Remove-Invalid-Characters-39fa17b1
#changed slightly for MSVA script

Function Remove-InvalidFileNameChars {
    <#
    .SYNOPSIS
    This is a PowerShell function to remove invalid characters from strings to be used as file names.

    .DESCRIPTION
    The function takes a string parameter called Name and returns a string that 
    has been stripped of invalid file name characters, i.e. *, :, \, /.  
    The Name parameter will also receive input from the pipeline.

    .PARAMETER Name
    Specifies the file name to strip of invalid characters.

    .INPUTS
    Parameter Name accepts System.String objects from the pipeline.

    .OUTPUTS
    System.String.  Outpus a string object

    .EXAMPLE
    Remove-InvalidFileNameChars -Name "<this>"
    PS C:\>Thisnameisanillegalfilename

    .NOTES
    It would be easiest to copy the function from the script file and place it in your profile.  
    However, you may also dot-source the script to load the function into PowerShell:
    i.e. PS C:\>. .\Remove-InvalidFileNameChars.ps1
    #>

    [CmdletBinding()]

    param([Parameter(Mandatory=$true,
        Position=0,
        ValueFromPipeline=$true, 
        ValueFromPipelineByPropertyName=$true)]
        [String]$Name
    )

    $result = [RegEx]::Replace($Name, "[{0}]" -f ([RegEx]::Escape
           ([String][System.IO.Path]::GetInvalidFileNameChars())), '')
    $result = $result.Replace("Microsoft-Virtual-Academy", "")
    while($result.Contains("--"))
    {
        $result = $result.Replace("--", "-")
    }

    return $result.Trim("-")
}</this>

Download-Content.ps1

cls
Write-Output ""
Write-Output ""
Write-Output ""
Write-Output ""
Write-Output ""
Write-Output ""
Write-Output ""
Write-Output ""
Write-Output ""
Write-Output ""
Write-Output "Starting"

$certPages = $("mcsd-application-lifecycle-management",
"mcsd-windows-store-apps-certification","mcsd-web-apps-certification")
$baseSaveLocation = "Z:\Learning\Microsoft Virtual Academy"

$pathToRemoveInvalidFileNameCharsScript = "$baseSaveLocation\Remove-InvalidFileNameChars.ps1"

#------------Don't edit below here----------------#

. "$pathToRemoveInvalidFileNameCharsScript"    
foreach($certPage in $certPages)
{
    $certUrl="http://www.microsoft.com/learning/en-us/$certPage.aspx"
    Write-Output "Downloading Page: $certUrl"
    $pageHtml=invoke-webrequest -uri $certUrl
    $destination="$baseSaveLocation\$(Remove-InvalidFileNameChars $certPage.Replace(" ","-"))"

    if (!(Test-Path $destination)) {
        New-Item -ItemType directory -Path $destination
    }
    
    $filteredLinks = $pageHtml.Links | Where-Object 
    { $_.href.ToLower().StartsWith("http://www.microsoftvirtualacademy.com/training-courses/") } 

    foreach($link in $filteredLinks)
    {        
        Write-Output "Downloading Page: $($link.href)"
        $trainingPageHtml=invoke-webrequest -uri $link.href        
        [string]$trainingTitle = $trainingPageHtml.AllElements | Where-Object 
        { $_.tagName.ToLower().StartsWith("title") } | Select-Object -ExpandProperty innerText {$_}
        $trainingTitle = $trainingTitle.Trim()
        $trainingDestination="$destination\$($link.innerText)-
         $(Remove-InvalidFileNameChars $trainingTitle.Replace(" ","-"))"

        if (!(Test-Path $trainingDestination)) {
            New-Item -ItemType directory -Path $trainingDestination
        }

        $idEducationTypePattern = [regex]"parent='(?<ideducationtype>[^']*)'"
        [int]$idEducationType = $idEducationTypePattern.Match
             ($trainingPageHtml.Content).Groups["idEducationType"].Value
        $jsonPostDataPattern = [regex]'showNextPanelEducationTypes
          ((?<ideducationtypeselected>[^"]*),(?<ideducationlevelselected>[^"]*),
          (?<isapproved>[^"]*),(?<numcontrol>[^"]*),this)'
        foreach($jsonPostData in $jsonPostDataPattern.Matches($trainingPageHtml.Content))
        {

            [int]$idEducationTypeSelected = 
              $jsonPostData.Groups["idEducationTypeSelected"].Value.TrimStart("(")
            [int]$idEducationLevelSelected = $jsonPostData.Groups["idEducationLevelSelected"].Value
            [int]$numControl = $jsonPostData.Groups["numControl"].Value
            $isApproved = $jsonPostData.Groups["isApproved"].Value
            $jsonPostUri = "http://www.microsoftvirtualacademy.com/Studies/EducationDetails.aspx/ShowNextPanelEducationTypes"
            $jsonPostBody = @{
                    idEducationTypeSelected = "$idEducationTypeSelected";
                    idEducationLevelSelected = $idEducationLevelSelected;
                    isSubscribe = $true;
                    selectedIsEnabled = "true";
                    numControl = $numControl;
                    idEducationType = "$idEducationType";
                    isApproved = "$isApproved";
                    culture="en-US"
                 }| ConvertTo-Json 

            $jsonInvokeResult = Invoke-RestMethod -Method Post 
               -Uri $jsonPostUri -ContentType "application/json" -Body $jsonPostBody 
        
            $ctIDPattern = [regex]'openEmbeddedVideo((?<id>.+));'
            foreach($ctID in $ctIDPattern.Matches($jsonInvokeResult.d.HtmlResponseMaterials))
            {
                $Id = $ctID.Groups["Id"].Value.TrimStart("(").Split(',')[0]
                $uriForTrainingVideo = "http://www.microsoftvirtualacademy.com/Content/
                       ViewContent.aspx?et=$idEducationType&m=$idEducationTypeSelected&ct=$Id"            
                Write-Output "Downloading Page: $uriForTrainingVideo"

                $trainingVideoPageHtml=invoke-webrequest -uri $uriForTrainingVideo
        
                [string]$trainingVideoTitle = $trainingVideoPageHtml.AllElements | 
                 Where-Object { $_.tagName.ToLower().StartsWith("title") } | Select-Object -ExpandProperty innerText {$_} 
                $trainingVideoTitle = $trainingVideoTitle.Trim()
                [string]$videoMp4Link = $trainingVideoPageHtml.Links | Where-Object 
                 {$_.href.EndsWith(".mp4") -and $_.outerText -eq "MP4"} | Select-Object -ExpandProperty href {$_} 
                $urlFileName = $($videoMp4Link.split("/")[-1])
                $videoMp4LocalFullName = "$($trainingDestination +"\" + 
                 $(Remove-InvalidFileNameChars $trainingVideoTitle.Replace(" ","-"))).mp4"

                if(!(Test-Path ($videoMp4LocalFullName))) 
                {
                    Write-Output "Downloading Video: $trainingVideoTitle to $videoMp4LocalFullName"
                    Start-BitsTransfer "$videoMp4Link" $videoMp4LocalFullName
                }
            }
        }
    }
}

Write-Output "Done"</id></numcontrol></isapproved></ideducationlevelselected></ideducationtypeselected></ideducationtype>

Configuration

• $baseSaveLocation - Set this to the location you want to save the videos to
• $certPages - This is an array of certification page names that you want to download content from, i.e.: for MCSD: Application Lifecycle Management which has a URL http://www.microsoft.com/learning/en-us/mcsd-application-lifecycle-management.aspx, the page name would be mcsd-application-lifecycle-management. Note that you will exclude the extension.
• $pathToRemoveInvalidFileNameCharsScript - This can stay the same unless you have placed the first script in a difference location to the base location.

Next Steps

The next steps for this script will be to try get it to download the PowerPoint slides for each video, currently you need to be logged in to download slides so this might not be ready for a while.