Example Episerver job for block property migration

MigrateHeroPanelOverlayJob

using System;
using System.Collections.Generic;
using System.Globalization;
using System.Linq;
using System.Text;
using EPiServer;
using EPiServer.Core;
using EPiServer.DataAccess;
using EPiServer.PlugIn;
using EPiServer.Scheduler;
using EPiServer.ServiceLocation;
using EPiServer.Web;
using Website.Models.Blocks;

namespace Website.Business.Jobs
{
    [ScheduledPlugIn(DisplayName = "[Migration] External hero panel overlay", SortIndex = 999999992)]
    public class MigrateHeroPanelOverlayJob : ScheduledJobBase
    {
        private IContentRepository _cms;
        private IContentVersionRepository _vers;

        public override string Execute()
        {
            _cms = ServiceLocator.Current.GetInstance<IContentRepository>();
            _vers = ServiceLocator.Current.GetInstance<IContentVersionRepository>();

            var links = _cms.GetDescendents(ContentReference.RootPage)
                .Union(_cms.GetDescendents(SiteDefinition.Current.GlobalAssetsRoot));
            var foundCount = 0;
            var updatedCount = 0;
            var errors = new List<string>();
            var found = new List<string>();

            foreach (var link in links)
            {
                var langs = _vers.ListPublished(link).GroupBy(v => v.LanguageBranch).Select(g => g.First().LanguageBranch).ToList();

                foreach (var lang in langs)
                {
                    ContentData item;

                    try
                    {
                        item = _cms.Get<ContentData>(link, CultureInfo.GetCultureInfo(lang));
                    }
                    catch (Exception ex)
                    {
                        errors.Add($"[{link.ID}]: {ex.Message}");
                        continue;
                    }

                    if (item is HeroPanelBlock && ((HeroPanelBlock) item).HideOverlay && ((HeroPanelBlock) item).Overlay != "no-overlay")
                    {
                        ++foundCount;
                        var writable = (HeroPanelBlock) item.CreateWritableClone();
                        found.Add($"[{writable.GetId()}] \"{writable.GetName()}\"");

                        try
                        {
                            writable.Overlay = "no-overlay";
                        }
                        catch (Exception ex)
                        {
                            errors.Add($"[{writable.GetId()}] \"{writable.GetName()}\": {ex.Message}");
                            continue;
                        }

                        _cms.Save((IContent) writable, SaveAction.Publish);
                        ++updatedCount;
                    }
                }
            }

            var result = $"{foundCount} blocks found, {updatedCount} updated.";

            if (found.Any())
            {
                var br = "<br>";
                var foundResult = new StringBuilder();
                foundResult.Append("Found:" + br);

                foreach (var fb in found)
                {
                    foundResult.Append(fb + br);
                }

                result += " " + foundResult;
            }

            if (errors.Any())
            {
                var br = "<br>";
                var errorResult = new StringBuilder();
                errorResult.Append("Errors:" + br);

                foreach (var error in errors)
                {
                    errorResult.Append(error + br);
                }

                result += " " + errorResult;
            }

            return result;
        }
    }
}