public static MvcHtmlString TextAreaWithMaxLengthFor <TViewModel, TValue>(this HtmlHelper <TViewModel> html,
Expression <Func <TViewModel, TValue> > expression,
TextAreaDimensions textAreaDimensions
, string optionalPlaceholderText
, IEnumerable <string> cssClasses
)
{
return(html.TextAreaWithMaxLengthFor(expression, textAreaDimensions, optionalPlaceholderText, cssClasses, true));
}
/// <summary>
/// Build style string for the TextArea.
/// </summary>
public static string BuildStyleString(TextAreaDimensions textAreaDimensions, TextAreaEnableType textAreaEnableType)
{
const string disabledBackgroundColor = "#DDDDDD";
var backgroundColorString = textAreaEnableType == TextAreaEnableType.Enabled ? string.Empty : " background-color: " + disabledBackgroundColor;
// We put in a "width" field (and not the "cols" attribute) when we are *NOT* in an IE browser AND we aren't using a monospaced font
var pixelWidthString = textAreaDimensions.ColumnWidthInPixels.HasValue ? $"width:{textAreaDimensions.ColumnWidthInPixels}px"
: "width:100%";
const string disableResizeString = "resize: none";
var styleString = $"{backgroundColorString};{pixelWidthString};{disableResizeString};";
return(styleString);
}
/// <summary>
/// Custom TextArea control that has the max chars left in another div
/// Only public for unit testing
/// </summary>
public static MvcHtmlString TextAreaWithMaxLengthFor <TViewModel, TValue>(this HtmlHelper <TViewModel> html,
Expression <Func <TViewModel, TValue> > expression,
TextAreaDimensions textAreaDimensions, string optionalPlaceholderText, IEnumerable <string> cssClasses)
{
int?maxLength = null;
var memberExpression = expression.Body as MemberExpression;
if (memberExpression != null)
{
var stringLengthAttribute =
memberExpression.Member.GetCustomAttributes(typeof(StringLengthAttribute), true)
.Cast <StringLengthAttribute>()
.SingleOrDefault();
if (stringLengthAttribute != null)
{
maxLength = stringLengthAttribute.MaximumLength;
}
}
var textAreaEnableType = TextAreaEnableType.Enabled;
var metadata = ModelMetadata.FromLambdaExpression(expression, html.ViewData);
var value = (string)metadata.Model;
var fieldName = ExpressionHelper.GetExpressionText(expression);
var fullBindingName = html.ViewContext.ViewData.TemplateInfo.GetFullHtmlFieldName(fieldName);
var fieldId = TagBuilder.CreateSanitizedId(fullBindingName);
var textAreaTag = new TagBuilder("textarea");
if (cssClasses != null)
{
foreach (var cssClass in cssClasses)
{
textAreaTag.AddCssClass(cssClass);
}
}
textAreaTag.Attributes.Add("name", fullBindingName);
textAreaTag.Attributes.Add("id", fieldId);
if (textAreaEnableType == TextAreaEnableType.Disabled)
{
textAreaTag.Attributes.Add("readonly", "readonly");
}
textAreaTag.Attributes.Add("style", BuildStyleString(textAreaDimensions, textAreaEnableType));
if (!string.IsNullOrWhiteSpace(optionalPlaceholderText))
{
textAreaTag.Attributes.Add("placeholder", optionalPlaceholderText);
}
textAreaTag.Attributes.Add("rows", textAreaDimensions.Rows.ToString(CultureInfo.InvariantCulture));
textAreaTag.InnerHtml = value;
var validationAttributes = html.GetUnobtrusiveValidationAttributes(fullBindingName, metadata);
foreach (var key in validationAttributes.Keys)
{
textAreaTag.Attributes.Add(key, validationAttributes[key].ToString());
}
// For varchar(max) consider -1 is the same as *unlimited*
if (maxLength.HasValue && maxLength > 0)
{
return(AddCharactersRemainingToTextArea(textAreaTag, fieldId, value, maxLength.Value,
textAreaDimensions.ColumnWidthInPixels.HasValue));
}
return(new MvcHtmlString(textAreaTag.ToString(TagRenderMode.Normal)));
}
/// <summary>
/// Custom TextArea control that has the max chars left in another div
/// Only public for unit testing
/// </summary>
public static MvcHtmlString TextAreaWithMaxLengthFor <TViewModel, TValue>(this HtmlHelper <TViewModel> html,
Expression <Func <TViewModel, TValue> > expression,
TextAreaDimensions textAreaDimensions, string optionalPlaceholderText)
{
return(html.TextAreaWithMaxLengthFor(expression, textAreaDimensions, optionalPlaceholderText, null));
}