Setting Image Properties using Powershell on existing Image Field

Question

I am trying to find a way to change the Properties (Alternate Text) of an image field in an item. Do you know how can I access those image properties using Sitecore Powershell?

Answer 1

Those properties are stored in the XML for the image field:

<image mediaid="{B4F11915-7EEF-4924-A8E4-B460D9929F59}" alt="Alt Text" height="168" width="300" hspace="" vspace="" />

You can easily update these by using the PSField.<fieldname> object:

$item = Get-Item -Path "master:/content/home"
$item.Image = Get-Item -Path "master:\media library\Project\Website\General\test"
$item.PSFields.Image.Alt = "Set Some Alt Text"
$item.PSFields.Image.Width = 300

etc...

Answer 2

You can use below script:

$mediaID = "mediaID"
Write-Progress -Activity $activity -Status "Checking if image exists" -PercentComplete $percentComplete -CurrentOperation $mediaID
$image = Get-Item -Path "master:" -ID $mediaID
if(!$image) { continue }
if([string]::IsNullOrEmpty($image.Alt)) {
    Write-Host "Updating $($image.ItemPath)"
    Write-Progress -Activity $activity -Status "Updating alt text for image" -PercentComplete $percentComplete -CurrentOperation $image.Alt
    $image.Alt = "your Alt Tag text"
}

The scripts is from here: https://gist.github.com/michaellwest/b71095cca46bd4b5aae4f1085dac0966