Programmatically Update Page Layouts

I updated my page layouts that I deployed as a feature, but found that I could not overwrite the Layout File. The solution was to add a new page layout and then you would have to associate the new layout with every page on your site that used it.

Obviously with a site of any size you'd have a lot of manual work to get this done, so doing it programmatically makes for a much better (and thorough) approach. After you've got your new page layouts, you could do something like this (in your event receiver class):

public override void FeatureActivated(SPFeatureReceiverProperties properties) {
        //replace current page layouts with new page layouts on all pages

        SPWeb web = SPContext.Current.Web;

        SwapPageLayout(web, "FullWidthContentWithTitleV1.aspx", "FullWidthContentWithTitleV2.aspx");
    }

    private void SwapPageLayout(SPWeb web, string oldPageLayoutName, string newPageLayoutName)
    {
        PublishingWeb pubWeb = PublishingWeb.GetPublishingWeb(web);

        PageLayout[] layouts = pubWeb.GetAvailablePageLayouts();
        PageLayout newLayout = null;
        PageLayout oldLayout = null;

        foreach (PageLayout layout in layouts)
        {
            if (layout.Name == newPageLayoutName)
            {
                newLayout = layout;
            }

            if (layout.Name == oldPageLayoutName)
            {
                oldLayout = layout;
            }
        }

        DoPageLayoutSwap(web, oldLayout, newLayout);
    }

    private void DoPageLayoutSwap(SPWeb web, PageLayout oldLayout, PageLayout newLayout)
    {
        string checkInComment = "PageLayout Feature automatically updated this page layout";

        if (PublishingWeb.IsPublishingWeb(web))
        {
            PublishingWeb pubWeb = PublishingWeb.GetPublishingWeb(web);
            
            

            foreach (SPListItem listItem in pubWeb.PagesList.Items)
            {
                if(PublishingPage.IsPublishingPage(listItem))
                {
                    PublishingPage page = PublishingPage.GetPublishingPage(listItem);
                    if (page.Layout.Name == oldLayout.Name)
                    {
                        page.CheckOut();
                        page.Layout = newLayout;
                        page.Update();
                        page.CheckIn(checkInComment);
                        SPFile pageFile = page.ListItem.File;
                        
                        pageFile.Publish(checkInComment);

                        if(listItem.ModerationInformation.Status.Equals(SPModerationStatusType.Pending))
                            pageFile.Approve(checkInComment);
                    }
                }
            }
        }

        //visit children
        foreach (SPWeb childWeb in web.Webs)
        {
            DoPageLayoutSwap(childWeb, oldLayout, newLayout);
        }
    }