Defaulting a section in a Razor view

Question

Here's the situation I'm trying to solve:

I have a main shared layout with a single section @RenderSection("Menu") that I want to default to a standard menu for the majority of my pages, but I would like to replace/override that section in a few sub pages. Is this possible with Razor at this stage in the game?

I was hoping I could possibly define the default implementation of that section in _ViewStart.cshtml but it doesn't seem to like it.

Would a Menu Partial view be better for this situation?

Edit:

I'm getting the following error with this code now: The following sections have been defined but have not been rendered for the layout page "~/Views/Shared/_Layout.cshtml": "menu".

_Layout.cshtml

            <div id="menu">
@if (IsSectionDefined("menu"))
{
    RenderSection("menu");
}
else { 
    <text>
            <ul>
                <li>@Html.ActionLink("Home", "Index", "Home")</li>
                <li><a href="#">Lookups</a>
                    <ul>
                        @Html.ActionLink("Product","Index","Product")
                    </ul>
                </li>
            </ul>
    </text>
}
        </div>

Index.cshtml

@section menu {
            <ul>
                <li>@Html.ActionLink("Product", "Index", "Product")</li>
                <li>@Html.ActionLink("Form Type", "Index", "Product")</li>
                <li>@Html.ActionLink("Supplier", "Index", "Product")</li>
            </ul>
    }

Answer 1

Ah... I was messing with this and found I could do it by just switching the logic around:

@RenderSection("Header", false)
@if (!IsSectionDefined("Header")) { 
<header>
    Default Header!
</header>
}

So if my pages don't define @section Header { ... }, it renders the default.

Answer 2

The IsSectionDefined method should suite your needs:

@if(IsSectionDefined("Menu")) {
    @RenderSection("Menu")
} else {
    <text>
        Default Menu Content.
    </text>
}

Update: I wrote a blog post to better illustrate the available options: Link