Following the points in Nuno's comment above I decided against using a custom deployer and have solved the problem using 2 event subscriptions of the Event System. On page publish I first localize the page, grab the localized filename from the localized linked metadata component and save the page. Then in a subsequent event I simply unlocalize the page. Here is my working code:
[TcmExtension("Publish or Unpublish Events")]
public class PublishOrUnpublishEvents : TcmExtension
{
public PublishOrUnpublishEvents()
{
EventSystem.Subscribe<Page, PublishEventArgs>(SetLocalizedPageFileName, EventPhases.Initiated);
EventSystem.Subscribe<Page, SetPublishStateEventArgs>(UnlocalizePageOncePublished, EventPhases.Initiated);
}
public void SetLocalizedPageFileName(Page page, PublishEventArgs args, EventPhases phase)
{
string localFilename = GetLocalilizedFileNameFromPageMetadata(page);
if (!string.IsNullOrEmpty(localFilename))
{
page.Localize();
if (page.TryCheckOut())
{
page.FileName = localFilename;
page.Save(true);
}
}
}
public void UnlocalizePageOncePublished(Page page, SetPublishStateEventArgs args, EventPhases phase)
{
string localFilename = GetLocalilizedFileNameFromPageMetadata(page);
if (!string.IsNullOrEmpty(localFilename))
page.UnLocalize();
}
private string GetLocalilizedFileNameFromPageMetadata(Page page)
{
string localFilename = string.Empty;
if (page.Metadata != null)
{
ItemFields fields = new ItemFields(page.Metadata, page.MetadataSchema);
if (fields.Contains("LocalizableMeta"))
{
ComponentLinkField localMetaField = fields["LocalizableMeta"] as ComponentLinkField;
Component component = localMetaField.Value;
ItemFields compFields = new ItemFields(component.Content, component.Schema);
if (compFields.Contains("LocalizedPageFilename"))
{
SingleLineTextField fileNameTextField = compFields["LocalizedPageFilename"] as SingleLineTextField;
localFilename = fileNameTextField.Value;
}
}
}
return localFilename;
}
}