While you can have an action that returns a partial view, you don’t need an action to render a partial view. RenderPartial takes the partial view and renders it, using the given model and view data if supplied, into the current (parent) view.
You might want an action that returns a partial view if you are using AJAX to load/reload part of a page. In that case, returning the full view is not desired since you only want to reload part of the page. In this case you can have the action just return the partial view that corresponds to that section of the page.
Standard mechanism
Making use of partial view within a normal view (no action needed)
...some html...
<% Html.RenderPartial( "Partial", Model.PartialModel ); %>
...more html..
Ajax mechanism
Reloading part of a page via AJAX (note partial is rendered inline in initial page load)
...some html...
<div id="partial">
<% Html.RenderPartial( "Partial", Model.PartialModel ); %>
</div>
...more html...
<script type="text/javascript">
$(function() {
$('#someButton').click( function() {
$.ajax({
url: '/controller/action',
data: ...some data for action...,
dataType: 'html',
success: function(data) {
$('#partial').html(data);
},
...
});
});
});
</script>
Controller for AJAX
public ActionResult Action(...)
{
var model = ...
...
if (Request.IsAjaxRequest())
{
return PartialView( "Partial", model.PartialModel );
}
else
{
return View( model );
}
}