Sitecore Placeholder Toggle Snippets

Foundation.Optimizations.config

<?xml version="1.0" encoding="utf-8" ?>
<configuration xmlns:patch="http://www.sitecore.net/xmlconfig/">
   <!-- :: Only applicable to CA environments :: -->
   <!-- this skips placeholder (Header and Footer) in EE but can be toggled back on with a button in the EE ribbon -->
  <sitecore>
      <pipelines>
          <mvc.renderPlaceholder>
              <!-- Patch to be first processor -->
              <processor type="Community.Foundation.Optimizations.Pipelines.MvcRenderPlaceholder.SkipPlaceholdersByUserSetting, Community.Foundation.Optimizations"
                         patch:before="*[1]"/>
        </mvc.renderPlaceholder>
    </pipelines>
  </sitecore>
</configuration>

SharedLayout.xml

<r><d id="{FE5D7FDF-89C0-4D99-9AA3-B5FBD009C9F3}"><r id="{BDE651C9-7988-4950-8E01-EA80106563A2}" uid="{C7A756BA-37FA-4A10-826A-D4C5911013F5}" par="Tooltip&amp;IsVisible=1&amp;Click=trigger%3Abutton%3Acheck&amp;Command=ToggleHeaderFooter&amp;ControlStateRequest&amp;PostponedCall&amp;AccessKey&amp;ConfigurationItem&amp;IsEnabled&amp;Id&amp;Behaviors&amp;PageCodeScriptFileName=%2Fsitecore%2Fshell%2Fclient%2FSitecore%2FCustom%2FExperienceEditor%2FCommands%2FToggleHeaderFooter.js&amp;RegistryKey=%2FCurrent_User%2FPage%20Editor%2FShow%2Fheaderfooter&amp;QueryKey" /></d></r>

SkipPlaceholdersByUserSetting.cs

using Sitecore.Mvc.Pipelines.Response.RenderPlaceholder;
using System.Linq;

namespace Community.Foundation.Optimizations.Pipelines.MvcRenderPlaceholder
{
    /// <summary>
    /// This processor is called for every placeholder that Sitecore renders.
    /// We will step in and abort processing for a placeholder if user toggled it off.
    /// </summary>
    public class SkipPlaceholdersByUserSetting : RenderPlaceholderProcessor
    {
        // List placeholder names that are hide-able
        // This could be done with a custom sitecore config
        static readonly string[] ApplicablePlaceholders = new string[] { "header", "footer"};

        public override void Process(RenderPlaceholderArgs args)
        {
            // Only applies to Experience Editor
            if (Sitecore.Context.PageMode.IsNormal)
                return;

            // Ignore if this placeholder is not hide-able
            if (!ApplicablePlaceholders.Contains(args.PlaceholderName))
                return;

            // Only applies to known user
            var profile = Sitecore.Context.User?.Profile;
            if (profile == null)
                return;

            // Match our checkbox registry key
            var registryKey = $"/{profile.ProfileUser.Name}/Page Editor/Show/headerfooter";
            var hide = profile[registryKey] != "on";

            // Exit if nothing to do... user wants to render placeholder as normal
            if (!hide)
                return;

            // Add a friendly message to authors so it doesn't seem broken
            var styles = "font-size: 1.5em; vertical-align: middle; padding: 0px 4px 0px 4px; top: -1px; position: relative;";
            var msg = $"<div><br /><p>&nbsp;&nbsp;&nbsp;[ Skipped <b style=\"{styles}\">{args.PlaceholderName}</b> placeholder. Toggle Header/Footer in ribbon above. ]</p><br /></div>";
            args.Writer.Write(msg);

            // Abort any further processing for this placeholder
            args.AbortPipeline();
        }
    }
}

ToggleHeaderFooter.js

define(["sitecore", "/-/speak/v1/ExperienceEditor/ExperienceEditor.js"], function (Sitecore, ExperienceEditor) {
    Sitecore.Commands.ToggleHeaderFooter =
    {
        canExecute: function (context) {
            return true;
        },
        execute: function (context) {
            ExperienceEditor.PipelinesUtil.generateRequestProcessor(
                "ExperienceEditor.ToggleRegistryKey.Toggle",
                function (response) {
                    window.top.location.reload(); // always reload on click
                },
                {
                    value: context.button.get("registryKey") // link is checked to registry key value
                }
            ).execute(context);
        }        
    };
});