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POMVC Razor: Helper method to render alternate content when empty
 

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  1. POMVC Razor: Helper method to render alternate content when empty
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    <p>I've got some data, and sometimes that data is blank. Instead of making a bunch of crazy logic on my view I'd rather use a helper method that will render the data if it exists, and render some HTML that just says "N/A" when the string is empty/null.</p> <p>Ideal syntax: <code>@Helpers.RenderThisOrThat(Model.CustomerPhone)</code></p> <p>If the <code>Model.CustomerPhone</code> (a string) is empty it will render this alternate HTML instead: <code>&lt;span class='muted'&gt;N/A&lt;/span&gt;</code></p> <p>Here's what we have so far:</p> <pre><code>@helper RenderThisOrThat(string stringToRender, string methodToGetAlternateText = null) { @RenderThisOrThat(MvcHtmlString.Create(stringToRender), methodToGetAlternateText) } @helper RenderThisOrThat(MvcHtmlString stringToRender, string methodToGetAlternateText = null) { if (string.IsNullOrWhiteSpace(stringToRender.ToHtmlString())) { if (!string.IsNullOrWhiteSpace(methodToGetAlternateText)) { @methodToGetAlternateText } &lt;span class='muted'&gt;N/A&lt;/span&gt; } @stringToRender } </code></pre> <p>This works just fine until we want to pass something other than a string into either parameter. For example when we have an email address we want it to be a link to that email and not just the string of the email.</p> <p><code>@Helpers.RenderThisOrThat(@&lt;a href="mailto:@Html.DisplayFor(m =&gt; m.CustomerEmail)"&gt;@Html.DisplayFor(m =&gt; m.CustomerEmail)&lt;/a&gt;)</code></p> <p>It gives us the error: "Cannot convert lambda expression to type 'string' because it is not a delegate type"</p> <p>We are at a loss for how to make this work... any help here?</p>
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    1. USChris Barr
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    1. COCan you write code like that? Besides your helper method I don't think Razor can interpret that
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      1. USAdriano Repetti
    2. COAre you referencing `System.Linq;` ?
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      1. USKami
    3. CO@Kami what's LINQ for?
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      1. USAdriano Repetti
 

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