Topic how to find out if the topic exists

Hi

I am trying to workout how I can find out if a topic exists or not in a view, so for example ho can I do

If @Html.Action("TopicBlock", "Topic", new { systemName = "TopicName" }) exists then
Do this
else
Do This


So what would this @Html.Action("TopicBlock", "Topic", new { systemName = "TopicName" }) line of code need to be

As you can tell I am new to MVC

Thanks
Spire

The TopicBlock action returns an empty string ("") if the topic with the systemName doesn't exist; therefore, you can check the length of the content returned by Html.Action() to see if a topic exists.

@{
    var topic = Html.Action("TopicBlock", "Topic", new { systemName = "TopicName" });
}

@if (topic.ToString().Length > 0)
{
    <div>Topic exists</div>
    @topic
}
else
{
    <div>Topic doesn't exist</div>
}

.

Hi

Thanks for you reply, however I don't know if I am missing somthing, but I was unable to make your code work, I kept getting an exception telling me that Html.Action("TopicBlock", "Topic", new { SystemName = Model.SeName.Replace("-", "") })) is not a string.

Anyway after further research I discoverd that Html.Action("TopicBlock", "Topic", new { SystemName = Model.SeName.Replace("-", "") })) is a  MvcHtmlString and has the IsNullOrEmpty method, so my final solution is below.

@if (MvcHtmlString.IsNullOrEmpty(Html.Action("TopicBlock", "Topic", new { SystemName = Model.SeName.Replace("-", "") })))
{
<p> Do Something</p>
}
else
{
<p> Do Nothing</p>
}

The above solution is so that I can grab the product name and if there is a topic with the same product name with no spaces in the topic name then I display the topic.