Working with Links database

Relink-Test.ps1

# Assuming Sitecore PowerShell Extensions 4.2 or newer is installed
# Assuming your Home has an "Image" field of type "Image"
# Assuming you have second item next to Home called Home2 that has an "Image" field of type "Image"
$coverImage = Get-Item 'master:\media library\Default Website\cover'
$scLogoImage = Get-item 'master:\media library\Default Website\sc_logo'
function Get-HomeItem { Get-item master:\content\home }
function Get-HomeChildItem { Get-item master:\content\Home\child } 
function Get-Home2Item { Get-item master:\content\home2 } 

function Set-CoverImage {
    Write-Host "`nReset 'home', 'child' and 'home2' to link to 'cover'- 3 items" -Fore Magenta
    (Get-HomeItem).Image = $coverImage
    (Get-HomeChildItem).Image = $coverImage
    (Get-Home2Item).Image = $coverImage

    Get-ItemReferrer -Item $coverImage
    
}

#Let's try some dumb global operations first

Set-CoverImage

Write-Host "`nRelinking all instances of 'cover' image to  'sc_logo'" -Fore Yellow
$coverImage | Update-ItemReferrer -NewTarget $scLogoImage

Write-Host "`n'cover' should no longer have links leading to it - 0 items " -Fore red
$coverImage | Get-ItemReferrer 

Write-Host "`n'sc_logo' should now be linked from all - 3 items" -Fore green
$scLogoImage | Get-ItemReferrer

Write-Host "`nRemoving links to 'sc_logo' from all items" -Fore Yellow
$scLogoImage | Update-ItemReferrer -RemoveLink

Write-Host "`n'sc_logo' should have no links to it - 0 items" -Fore red
$scLogoImage | Get-ItemReferrer

#Let's try some filtering...
Set-CoverImage

Write-Host "`nRemove links to the 'cover' image from all items under 'master:\content\home'" -Fore Yellow
Get-ChildItem master:\content\home -WithParent -Recurse |   # get items under home
    Get-ItemReference -ItemLink |                           # get all items that they are refering to
    ? { $_.TargetItemID -eq $coverImage.ID } |              # filter only references to $coverImage
    Update-ItemReferrer -RemoveLink                         # remove links

Write-Host "`n'cover' should have 1 link leading from 'home2'" -Fore green
$coverImage | Get-ItemReferrer

Set-CoverImage

Write-Host "`nUpdate all links to 'cover' image to point to 'sc_logo' from all immediate children of /sitecore/content" -Fore Yellow
Get-ChildItem master:\content |                     # get items immediately under 'under home'content'
    Get-ItemReference -ItemLink |                   # get all items that they are refering to
    ? { $_.TargetItemID -eq $coverImage.ID } |      # filter only references to $coverImage
    Update-ItemReferrer -NewTarget $scLogoImage

Write-Host "`n'cover' should have link from home2/child - 1 item" -Fore green
$coverImage | Get-ItemReferrer

Write-Host "`n'sc_logo' should have links leading from 'home' and 'home2' - 2 items" -Fore green
$scLogoImage | Get-ItemReferrer