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

The more elegant way to do this is to move partial view scripts into separate file and then render it in Scripts section of view:

<h2>This is the view</h2>

@Html.RenderPartial("_Partial")

@section Scripts
{
    @Html.RenderPartial("_PartialScripts")

    <script type="text/javascript">
        alert("I'm a view script.");
    </script>
}

The partial view _Partial.cshtml:

<p>This is the partial.</p>

The partial view _PartialScripts.cshtml with scripts only:

<script type="text/javascript">
    alert("I'm a partial script!");
</script>

Answer 2

Base on the answer from Mr Bell And Shimmy above, I add on extra function for Bundle script.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Text;
using System.Web.Mvc;
namespace ABC.Utility
{
public static  class PartialViewHelper
{
    public static string RequireScript(this HtmlHelper html, string path, int priority = 1)
    {
        var requiredScripts = HttpContext.Current.Items["RequiredScripts"] as List<ResourceInclude>;
        if (requiredScripts == null) HttpContext.Current.Items["RequiredScripts"] = requiredScripts = new List<ResourceInclude>();
        if (!requiredScripts.Any(i => i.Path == path)) requiredScripts.Add(new ResourceInclude() { Path = path, Priority = priority });
        return null;
    }

    public static string RequireBundleStyles(this HtmlHelper html, string bundleName)
    {
        var a = System.Web.Optimization.Styles.Render(bundleName);
        var requiredStyles = HttpContext.Current.Items["RequiredStyles"] as IHtmlString;
        if (requiredStyles == null) HttpContext.Current.Items["RequiredStyles"] = requiredStyles = a;
        return null;
    }

    public static string RequireBundleScripts(this HtmlHelper html, string bundleName)
    {
        var a=System.Web.Optimization.Scripts.Render(bundleName);
        var requiredScripts = HttpContext.Current.Items["RequiredScripts"] as IHtmlString;
        if (requiredScripts == null) HttpContext.Current.Items["RequiredScripts"] = requiredScripts = a;
        return null;
    }

    public static HtmlString EmitRequiredBundleStyles(this HtmlHelper html)
    {
        var requiredStyles = HttpContext.Current.Items["RequiredStyles"] as IHtmlString;
        if (requiredStyles == null) return null;
        return MvcHtmlString.Create(requiredStyles.ToHtmlString()) ;
    }

    public static HtmlString EmitRequiredBundleScripts(this HtmlHelper html)
    {
        var requiredScripts = HttpContext.Current.Items["RequiredScripts"] as IHtmlString;
        if (requiredScripts == null) return null;
        return MvcHtmlString.Create(requiredScripts.ToHtmlString());
    }

    public static HtmlString EmitRequiredScripts(this HtmlHelper html)
    {
        var requiredScripts = HttpContext.Current.Items["RequiredScripts"] as List<ResourceInclude>;
        if (requiredScripts == null) return null;
        StringBuilder sb = new StringBuilder();
        foreach (var item in requiredScripts.OrderByDescending(i => i.Priority))
        {
            sb.AppendFormat("<script src=\"{0}\" type=\"text/javascript\"></script>\n", item.Path);
        }
        return new HtmlString(sb.ToString());
    }
    public class ResourceInclude
    {
        public string Path { get; set; }
        public int Priority { get; set; }
    }
}//end class
}// end namespace  

Sample on PartialView :- @Html.RequireBundleStyles("~/bundles/fileupload/bootstrap/BasicPlusUI/css"); @Html.RequireBundleScripts("~/bundles/fileupload/bootstrap/BasicPlusUI/js");

Sample on MasterPage :- @Html.EmitRequiredBundleStyles()

Answer 3

Use @using(Html.Delayed()){ ...your content... } extensions from answer https://stackoverflow.com/a/18790222/1037948 to render any content (scripts or just HTML) later in the page. Internal Queue should ensure correct ordering.

Answer 4

The way I dealt with this is to write a couple extension methods to the HtmlHelper class. That allows partials views to say that they require a script, and then in the layout view that writes the tag I call to my helper method to emit the required scripts

Here are the helper methods:

public static string RequireScript(this HtmlHelper html, string path, int priority = 1)
{
    var requiredScripts = HttpContext.Current.Items["RequiredScripts"] as List<ResourceInclude>;
    if (requiredScripts == null) HttpContext.Current.Items["RequiredScripts"] = requiredScripts = new List<ResourceInclude>();
    if (!requiredScripts.Any(i => i.Path == path)) requiredScripts.Add(new ResourceInclude() { Path = path, Priority = priority });
    return null;
}

public static HtmlString EmitRequiredScripts(this HtmlHelper html)
{
    var requiredScripts = HttpContext.Current.Items["RequiredScripts"] as List<ResourceInclude>;
    if (requiredScripts == null) return null;
    StringBuilder sb = new StringBuilder();
    foreach (var item in requiredScripts.OrderByDescending(i => i.Priority))
    {
        sb.AppendFormat("<script src=\"{0}\" type=\"text/javascript\"></script>\n", item.Path);
    }
    return new HtmlString(sb.ToString());
}
public class ResourceInclude
{
    public string Path { get; set; }
    public int Priority { get; set; }
}

Once you have that in place your partial view just needs to call @Html.RequireScript("/Path/To/Script").

And in the layout view's head section you call @Html.EmitRequiredScripts().

An added bonus of this is that it allows you to weed out duplicate script requests. If you have multiple views/partial views that need a given script you can safely assume that you will only output it once

Answer 5

This functionality is also implemented in ClientDependency.Core.Mvc.dll. It provides the html helpers: @Html.RequiresJs and @Html.RenderJsHere(). Nuget package: ClientDependency-Mvc

Answer 6

You could have a second partial that is only in charge of injecting the necessary javascript. Place several scripts in there around @if blocks, if you want:

@model string
@if(Model == "bla") {
    <script type="text/javascript">...</script>
}

@else if(Model == "bli") {
    <script type="text/javascript">...</script>
}

This could obviously be cleaned up a bit, but then, in the Scripts section of your view:

@section Scripts
{
    @Html.Partial("_Scripts", "ScriptName_For_Partial1")
}

Again, it might not win a beauty prize but it will work.