/// <summary>
/// Displays multiple table header columns with filter and order information
/// </summary>
/// <typeparam name="TModel">The type of the filter object</typeparam>
/// <param name="htmlHelper">The HTML helper instance that this method extends</param>
/// <param name="formAction">The filter form action url</param>
/// <param name="orderPropertyExpression">An expression that identifies the order property</param>
/// <param name="orderDirectionExpression">An expression that identifies the order direction property</param>
/// <param name="expression">An expression that identifies the columns properties</param>
/// <param name="columnOptions">Formatting options</param>
/// <returns>Multiple table header columns elements for the specified properties in the filter object</returns>
public static MvcHtmlString TableHeaderColumnsFor <TModel>(this HtmlHelper <TModel> htmlHelper, string formAction, Expression <Func <TModel, string> > orderPropertyExpression,
Expression <Func <TModel, OrderDirection> > orderDirectionExpression, Expression <Func <TModel, object> > expression, TableHeaderColumnOptions columnOptions)
{
StringBuilder headerColumns = new StringBuilder();
columnOptions = columnOptions ?? new TableHeaderColumnOptions();
ModelMetadata orderPropertyMetadata = ModelMetadata.FromLambdaExpression(orderPropertyExpression, htmlHelper.ViewData);
ModelMetadata orderDirectionMetadata = ModelMetadata.FromLambdaExpression(orderDirectionExpression, htmlHelper.ViewData);
foreach (var argument in (expression.Body as NewExpression).Arguments)
{
string expressionString = ExpressionHelper.GetExpressionText(Expression.Lambda(argument, expression.Parameters));
ModelMetadata metadata = ModelMetadata.FromStringExpression(expressionString, htmlHelper.ViewData);
headerColumns.Append(CreateColumn(formAction, metadata.PropertyName, metadata.DisplayName ?? metadata.PropertyName, orderPropertyMetadata.PropertyName, orderPropertyMetadata.Model.ToString(),
orderDirectionMetadata.PropertyName, (OrderDirection)Enum.Parse(typeof(OrderDirection), orderDirectionMetadata.Model.ToString(), true), htmlHelper.ViewData.Model,
columnOptions));
}
return(new MvcHtmlString(headerColumns.ToString()));
}
/// <summary>
/// Generates a table header column (th)
/// </summary>
/// <typeparam name="TModel">The type of the object that will be used to generate a url querystring</typeparam>
/// <param name="formAction">The filter form action url</param>
/// <param name="propertyName">The column property name</param>
/// <param name="displayName">The column display name</param>
/// <param name="orderPropertyName">The filter form order property name</param>
/// <param name="orderPropertyValue">The filter form order property value</param>
/// <param name="orderDirectionProperty">The filter form order direction property name</param>
/// <param name="orderDirectionValue">The filter form order direction property value</param>
/// <param name="filterModel">The object instance that will be used to generate a url querystring</param>
/// <param name="columnOptions">Formatting options</param>
/// <returns>Table header column HTML string</returns>
private static string CreateColumn <TModel>(string formAction, string propertyName, string displayName, string orderPropertyName, string orderPropertyValue, string orderDirectionProperty,
OrderDirection orderDirectionValue, TModel filterModel, TableHeaderColumnOptions columnOptions)
{
TagBuilder th = new TagBuilder("th");
TagBuilder a = new TagBuilder("a");
if (propertyName.Equals(orderPropertyValue, StringComparison.OrdinalIgnoreCase))
{
a.Attributes.Add("href", formAction + filterModel.ToQueryString(new KeyValuePair <object, object>(orderDirectionProperty,
orderDirectionValue == OrderDirection.Ascending ? OrderDirection.Descending.ToString() : OrderDirection.Ascending.ToString())));
a.InnerHtml = displayName;
if (orderDirectionValue == OrderDirection.Ascending)
{
if (!string.IsNullOrWhiteSpace(columnOptions.AscendingContainerCssClass))
{
th.AddCssClass(columnOptions.AscendingContainerCssClass);
}
if (!string.IsNullOrWhiteSpace(columnOptions.AscendingLinkCssClass))
{
a.AddCssClass(columnOptions.AscendingLinkCssClass);
}
if (columnOptions.AscendingLinkAdditionalContentPosition == TableHeaderColumnOptions.AdditionalContentPosition.AfterTitle &&
!string.IsNullOrWhiteSpace(columnOptions.AscendingLinkAdditionalContent))
{
a.InnerHtml += columnOptions.AscendingLinkAdditionalContent;
}
else if (columnOptions.AscendingLinkAdditionalContentPosition == TableHeaderColumnOptions.AdditionalContentPosition.BeforeTitle &&
!string.IsNullOrWhiteSpace(columnOptions.AscendingLinkAdditionalContent))
{
a.InnerHtml = columnOptions.AscendingLinkAdditionalContent + a.InnerHtml;
}
}
else
{
if (!string.IsNullOrWhiteSpace(columnOptions.DescendingContainerCssClass))
{
th.AddCssClass(columnOptions.DescendingContainerCssClass);
}
if (!string.IsNullOrWhiteSpace(columnOptions.DescendingLinkCssClass))
{
a.AddCssClass(columnOptions.DescendingLinkCssClass);
}
if (columnOptions.DescendingLinkAdditionalContentPosition == TableHeaderColumnOptions.AdditionalContentPosition.AfterTitle &&
!string.IsNullOrWhiteSpace(columnOptions.DescendingLinkAdditionalContent))
{
a.InnerHtml += columnOptions.DescendingLinkAdditionalContent;
}
else if (columnOptions.DescendingLinkAdditionalContentPosition == TableHeaderColumnOptions.AdditionalContentPosition.BeforeTitle &&
!string.IsNullOrWhiteSpace(columnOptions.DescendingLinkAdditionalContent))
{
a.InnerHtml = columnOptions.DescendingLinkAdditionalContent + a.InnerHtml;
}
}
}
else
{
a.Attributes.Add("href", formAction + filterModel.ToQueryString(new KeyValuePair <object, object>(orderPropertyName, propertyName)));
a.InnerHtml = displayName;
if (!string.IsNullOrWhiteSpace(columnOptions.ContainerCssClass))
{
th.AddCssClass(columnOptions.ContainerCssClass);
}
if (!string.IsNullOrWhiteSpace(columnOptions.LinkCssClass))
{
a.AddCssClass(columnOptions.LinkCssClass);
}
if (columnOptions.LinkAdditionalContentPosition == TableHeaderColumnOptions.AdditionalContentPosition.AfterTitle &&
!string.IsNullOrWhiteSpace(columnOptions.LinkAdditionalContent))
{
a.InnerHtml += columnOptions.LinkAdditionalContent;
}
else if (columnOptions.LinkAdditionalContentPosition == TableHeaderColumnOptions.AdditionalContentPosition.BeforeTitle &&
!string.IsNullOrWhiteSpace(columnOptions.LinkAdditionalContent))
{
a.InnerHtml = columnOptions.LinkAdditionalContent + a.InnerHtml;
}
}
th.InnerHtml = a.ToString();
return(th.ToString());
}
/// <summary>
/// Displays an unique table header column with filter and order information
/// </summary>
/// <typeparam name="TModel">The type of the filter object</typeparam>
/// <typeparam name="TProperty">The type of the property in the filter object</typeparam>
/// <param name="htmlHelper">The HTML helper instance that this method extends</param>
/// <param name="formAction">The filter form action url</param>
/// <param name="orderPropertyExpression">An expression that identifies the order property</param>
/// <param name="orderDirectionExpression">An expression that identifies the order direction property</param>
/// <param name="expression">An expression that identifies the column property</param>
/// <param name="columnOptions">Formatting options</param>
/// <returns>A table header column element for the specified property in the filter object</returns>
public static MvcHtmlString TableHeaderColumnFor <TModel, TProperty>(this HtmlHelper <TModel> htmlHelper, string formAction, Expression <Func <TModel, string> > orderPropertyExpression,
Expression <Func <TModel, OrderDirection> > orderDirectionExpression, Expression <Func <TModel, TProperty> > expression, TableHeaderColumnOptions columnOptions)
{
ModelMetadata metadata = ModelMetadata.FromLambdaExpression(expression, htmlHelper.ViewData);
ModelMetadata orderPropertyMetadata = ModelMetadata.FromLambdaExpression(orderPropertyExpression, htmlHelper.ViewData);
ModelMetadata orderDirectionMetadata = ModelMetadata.FromLambdaExpression(orderDirectionExpression, htmlHelper.ViewData);
columnOptions = columnOptions ?? new TableHeaderColumnOptions();
return(new MvcHtmlString(CreateColumn(formAction, metadata.PropertyName, metadata.DisplayName ?? metadata.PropertyName, orderPropertyMetadata.PropertyName, orderPropertyMetadata.Model.ToString(),
orderDirectionMetadata.PropertyName, (OrderDirection)Enum.Parse(typeof(OrderDirection), orderDirectionMetadata.Model.ToString(), true), htmlHelper.ViewData.Model,
columnOptions)));
}
