public static IHtmlContent AggregationOperatorHtml(this Column col, Type destinationType, IStringLocalizer localizer, string selection, string selectCss = null)
{
if (!col.CanAggregate)
{
return(null);
}
var expression =
col.For;
Type sourceType = expression.Metadata.ContainerType;
Type propertyType = expression.Metadata.ModelType;
if (destinationType == null)
{
destinationType = sourceType;
}
else if (!sourceType.GetTypeInfo().IsAssignableFrom(destinationType))
{
return(null);
}
var path = expression.Name;
bool simple = path.IndexOf('.') < 0;
string countDistinctAlias = null;
var operations = QueryAttribute.AllowedAggregationsForType(propertyType, col.Queries.Value);
string displayName = null;
if (!simple)
{
operations = operations & (GroupingOptions.Group);
}
else if (col.ColumnConnection != null)
{
operations = operations & (GroupingOptions.Group | GroupingOptions.CountDistinct);
displayName = col.ColumnConnection.DisplayProperty.Name;
}
if ((operations & GroupingOptions.CountDistinct) == GroupingOptions.CountDistinct)
{
var ti = destinationType.GetTypeInfo();
var prop = ti.GetProperty(path + "Count");
if (prop == null || !canCount(prop.PropertyType))
{
prop = ti.GetProperty(path);
}
if (prop != null && canCount(prop.PropertyType))
{
countDistinctAlias = prop.Name;
}
}
if (countDistinctAlias == null)
{
operations = operations & (~GroupingOptions.CountDistinct);
}
if (operations == GroupingOptions.None)
{
return(null);
}
var selections = QueryAttribute.GroupOptionsToEnum(operations);
StringBuilder sb = new StringBuilder();
sb.Append("<select name ='");
sb.Append(path);
sb.Append("' ");
if (displayName != null)
{
sb.Append("data-display-name='");
sb.Append(displayName);
sb.Append("' ");
}
if (!string.IsNullOrEmpty(selectCss))
{
sb.Append("class='");
sb.Append(selectCss);
sb.Append("' ");
}
if (countDistinctAlias != null)
{
sb.Append("data-count-distinct='");
sb.Append(countDistinctAlias);
sb.Append("' ");
}
sb.Append(">");
foreach (var option in selections)
{
sb.Append("<option value='");
sb.Append(HtmlEncoder.Default.Encode(option.Key));
sb.Append("' ");
if (option.Key == selection)
{
sb.Append("selected ");
}
sb.Append(">");
sb.Append(HtmlEncoder.Default.Encode(localizer == null ? option.Value : localizer[option.Value]));
sb.Append("</option>");
}
sb.Append("</select>");
return(new HtmlString(sb.ToString()));
}
