Embarrassingly newbie question:
I have a string field in my model that contains line breaks.
@Html.DisplayFor(x => x.MultiLineText)
does not display the line breaks.
Obviously I could do some fiddling in the model and create another field that replaces \n with <br/>, but that seems kludgy. What's the textbook way to make this work?
A HtmlHelper extension method to display string values with line breaks:
public static MvcHtmlString DisplayWithBreaksFor<TModel, TValue>(this HtmlHelper<TModel> html, Expression<Func<TModel, TValue>> expression)
{
var metadata = ModelMetadata.FromLambdaExpression(expression, html.ViewData);
var model = html.Encode(metadata.Model).Replace("\r\n", "<br />\r\n");
if (String.IsNullOrEmpty(model))
return MvcHtmlString.Empty;
return MvcHtmlString.Create(model);
}
And then you can use the following syntax:
@Html.DisplayWithBreaksFor(m => m.MultiLineField)
MvcHtmlString.Empty when the value is null or empty I would invoke the standard HtmlHelper.DisplayFor method so that any NullDisplayText decoration can be used.
DisplayTemplate instead of introducing a HtmlHelper-method has the advantage, that it trickles down to properties and views that are not explicitly defined (see my answer).i recommend formatting the output with css instead of using cpu consuming server side strings manipulation like .replace,
just add this style property to render multiline texts :
.multiline
{
white-space: pre-wrap;
}
then
<div class="multiline">
my
multiline
text
</div>
newlines will render like br elements, test it here https://refork.codicode.com/xaf4
Html.DisplayFor can still be used apply the [System.ComponentModel.DataAnnotations.DataType(System.ComponentModel.DataAnnotations.DataType.MultilineText)] attribute to the MultiLineText property on the model and create a DisplayTemplate with the contents @model string <span class="multiline">@Model</span>
In your view, you can try something like
@Html.Raw(Html.Encode(Model.MultiLineText).Replace("\n", "<br />"))
.Replace("\r\n", ...). Also, the solution from cwills below is much better, in my opinion.
ViewData instead of a regular property, but in ASP.NET Core Razor, I had to use @Html.Raw(((string)ViewData["MyText"]).Replace("\n", "<br />"))
@Html.Raw(field.Replace("\n", "<br />"))The display template is probably the best solution but there is another easy option of using an html helper if you know you're just displaying a string, e.g.:
namespace Shaul.Web.Helpers
{
public static class HtmlHelpers
{
public static IHtmlString ReplaceBreaks(this HtmlHelper helper, string str)
{
return MvcHtmlString.Create(str.Split(new string[] { "\r\n", "\n" }, StringSplitOptions.None).Aggregate((a, b) => a + "<br />" + b));
}
}
}
And then you'd use it like:
@using Shaul.Web.Helpers
@Html.ReplaceBreaks(Model.MultiLineText)
You create a display template for your data. Here's a post detailing how to do it. How do I create a MVC Razor template for DisplayFor()
In that template you do the actual translating of newlines into
and whatever other work needs to be done for presentation.
Inspired by DisplayTemplates for common DataTypes,
I override (introduce?) a default DisplayTemplate for DataType.MultilineText, /Views/Shared/DisplayTemplates/MultilineText.cshtml containing just this line:
<span style="white-space: pre-wrap">@this.Model</span>
(Of course you could replace this style, by a css-class, or replace newlines inside the view, if you prefer that.)
I guess this template is automatically resolved, because I had no need for UIHint or any other reference or registration.
Using the DisplayTemplate instead of introducing a HtmlHelper-method has the advantage, that it trickles down to properties and views that are not explicitly defined.
E.g. DisplayFor(MyClassWithMultilineProperties) will now also correctly display MyClassWithMultilineProperties.MyMultilineTextProperty, if the property was annotated with [DataType(DataType.MultilineText)].
Try using
@Html.Raw("<p>" + Html.LabelFor(x => x.Name) + "</p>")
Here's another extension method option.
public static IHtmlString DisplayFormattedFor<TModel>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, string>> expression)
{
string value = Convert.ToString(ModelMetadata.FromLambdaExpression(expression, htmlHelper.ViewData).Model);
if (string.IsNullOrWhiteSpace(value))
{
return MvcHtmlString.Empty;
}
value = string.Join("<br/>", value.Split(new[] { Environment.NewLine }, StringSplitOptions.None).Select(HttpUtility.HtmlEncode));
return new HtmlString(value);
}
I had this problem with ASP.NET Core 6. The previous answers here did not work with a linq expression in Html.DisplayFor. Instead I was constantly getting the <br/> tag escaped out in the output HTML. Trying HtmlString helper methods suggestions did not work.
The following solution was discovered through trial and error. The InfoString had CRLF replaced with the <br/> tags as shown in the property code.
Works
@Html.Raw(@Convert.ToString(item.InfoString))
Did not work
@Html.DisplayFor(modelItem => item.InfoString)
FYI - my Info String property:
public string InfoString
{
get { return MyInfo.Replace(Environment.NewLine,"<br />"); }
}
