soen

SiteContext targetSiteContext = SiteContext.GetSite(sitename);
using (var context = new SiteContextSwitcher(targetSiteContext))
{
    // do something on the new site context
    Item myItem = context.Database.GetItem("ID");
}

soen

public static class TemplateItemExtensions
{
  public static IEnumerable<TemplateFieldItem> GetFieldsOfSelfAndBaseTemplates(this TemplateItem self)
  {
    var templateFieldItems = new Dictionary<ID, TemplateFieldItem>();
    GetAllFieldsForTemplate(self, templateFieldItems);

    return templateFieldItems.Values;
  }

soen

Template template = TemplateManager.GetTemplate(new ID(""), Sitecore.Context.Database);
TemplateField[] allFields = template.GetFields(true);

soen

using Sitecore.Form.Core.Attributes;
using System;
using System.ComponentModel;
using System.Web.UI;

namespace CustomWFFM.CustomFieldTypes
{
  [ValidationProperty("Text")]
  public class SingleLineTextWithPlaceholderField : Sitecore.Form.Web.UI.Controls.SingleLineText
  {

soen

using System.ComponentModel;
using Sitecore.Data.Items;

namespace CustomWFFM.CustomFieldTypes.Mvc
{
  public class SingleLineTextWithPlaceholderField : Sitecore.Forms.Mvc.Models.Fields.SingleLineTextField
  {
    [DefaultValue("")]
    public string PlaceholderText { get; set; }

soen

@using Sitecore.Mvc
@model CustomWFFM.CustomFieldTypes.Mvc.SingleLineTextWithPlaceholderField

@if (!Model.Visible)
{
    return;
}

<div class="@Model.CssClass field-border">

soen

using System.Linq;
using Sitecore.Configuration;
using Sitecore.Data.Items;
using Sitecore.Diagnostics;
using Sitecore.Pipelines.ExpandInitialFieldValue;

namespace CustomExpandTokenProcessors.Pipelines
{
  public class NextSortOrderReplacer : ExpandInitialFieldValueProcessor
  {

soen

using Sitecore.Diagnostics;
using Sitecore.Pipelines.ExpandInitialFieldValue;

namespace CustomExpandTokenProcessors.Pipelines
{
  public class CustomTokenReplacer : ExpandInitialFieldValueProcessor
  {
    private const string Token = "$customtoken";

    public override void Process(ExpandInitialFieldValueArgs args)

soen

using System;
using System.Text.RegularExpressions;
using Sitecore.Data.Items;
using Sitecore.Diagnostics;
using Sitecore.Pipelines.ExpandInitialFieldValue;

namespace CustomExpandTokenProcessors.Pipelines
{
  public class QueryTokenReplacer : ExpandInitialFieldValueProcessor
  {

soen

// Decompiled with JetBrains decompiler
// Type: Sitecore.Sites.SiteContext
// Assembly: Sitecore.Kernel, Version=8.1.0.0, Culture=neutral, PublicKeyToken=null
// 
// NOTE: This is not the complete implementation, only fractions of the important parts related 
//       to getting cookie by key from the site-context.
// 

namespace Sitecore.Sites
{