Populate a Razor Section From a Partial

Question

My main motivation for trying to do this is to get Javascript that is only required by a partial at the bottom of the page with the rest of the Javascript and not in the mid

Answer 1

For those looking for the aspnet core 2.0 version:

    using System.Collections.Generic;
    using System.Linq;
    using System.Text;
    using Microsoft.AspNetCore.Html;
    using Microsoft.AspNetCore.Http;

    public static class HttpContextAccessorExtensions
    {
        public static string RequireScript(this IHttpContextAccessor htmlContextAccessor, string path, int priority = 1)
        {
            var requiredScripts = htmlContextAccessor.HttpContext.Items["RequiredScripts"] as List;
            if (requiredScripts == null) htmlContextAccessor.HttpContext.Items["RequiredScripts"] = requiredScripts = new List();
            if (requiredScripts.All(i => i.Path != path)) requiredScripts.Add(new ResourceInclude() { Path = path, Priority = priority });
            return null;
        }

        public static HtmlString EmitRequiredScripts(this IHttpContextAccessor htmlContextAccessor)
        {
            var requiredScripts = htmlContextAccessor.HttpContext.Items["RequiredScripts"] as List;
            if (requiredScripts == null) return null;
            StringBuilder sb = new StringBuilder();
            foreach (var item in requiredScripts.OrderByDescending(i => i.Priority))
            {
                sb.AppendFormat("\n", item.Path);
            }
            return new HtmlString(sb.ToString());
        }
        public class ResourceInclude
        {
            public string Path { get; set; }
            public int Priority { get; set; }
        }
    }

Add to your layout after the scripts render section call:

@HttpContextAccessor.EmitRequiredScripts()

And in your partial view:

@inject IHttpContextAccessor HttpContextAccessor

...

@HttpContextAccessor.RequireScript("/scripts/moment.min.js")