Set an PropertyBag property as Indexable (Queryable via Search)

Set Indexable PropertyBag property.ps1

cls
Add-PSSnapin Microsoft.SharePoint.Powershell -ea SilentlyContinue

$w = Get-SPWeb "http://pub.pdogs.local/news"
$allProps = $w.AllProperties
$allProps.Keys | ? { $_ -match "^vti_indexedpropertykeys" } | % { "$_ = [$($allProps[$_])]" }
Write-Host 

$propertyName = "MyWebTemplateID"
# indexedpropertykey must be base64 encoded value of the unicode string
$encodedPropertyName = [Convert]::ToBase64String([System.Text.Encoding]::Unicode.GetBytes($propertyName))

# set the regular web property value
$allProps[$propertyName] = "CorpNews"

# now set it as indexable
$ipPropertyName = "vti_indexedpropertykeys"
$existingIPPropertyValue = $allProps[$ipPropertyName]
if ($existingIPPropertyValue -notlike "*$encodedPropertyName*") {
    # the property name is not in the indexedpropertykeys property, so add it including the terminating pipe | character
    Write-Host "Setting $ipPropertyName property"
    $allProps[$ipPropertyName] = "$existingIPPropertyValue$encodedPropertyName|"
}
$w.Update()