/// <summary>
/// Model-Based main function
/// </summary>
/// <typeparam name="TModel">Current ViewModel</typeparam>
/// <typeparam name="TItem">ViewModel Item</typeparam>
/// <typeparam name="TValue">ViewModel Item type of the value</typeparam>
/// <typeparam name="TKey">ViewModel Item type of the key</typeparam>
/// <param name="htmlHelper">MVC Html helper class that is being extended</param>
/// <param name="modelMetadata">Model Metadata</param>
/// <param name="listName">Name of each checkbox in a list (use this name to POST list values array back to the controller)</param>
/// <param name="sourceDataExpr">Data list to be used as a source for the list (set in viewmodel)</param>
/// <param name="valueExpr">Data list value type to be used as checkbox 'Value'</param>
/// <param name="textToDisplayExpr">Data list value type to be used as checkbox 'Text'</param>
/// <param name="htmlAttributesExpr">Data list HTML tag attributes, to allow override of htmlAttributes for each checkbox (e.g. 'item => new { data_relation_id = item.RelationID }')</param>
/// <param name="selectedValuesExpr">Data list of selected items (should be of same data type as a source list)</param>
/// <param name="htmlAttributes">Each checkbox HTML tag attributes (e.g. 'new { class="somename" }')</param>
/// <param name="htmlListInfo">Settings for HTML wrapper of the list (e.g. 'new HtmlListInfo2(HtmlTag2.vertical_columns, 2, new { style="color:green;" })')</param>
/// <param name="disabledValues">String array of values to disable</param>
/// <param name="position">Direction of the list (e.g. 'Position2.Horizontal' or 'Position2.Vertical')</param>
/// <returns>HTML string containing checkbox list</returns>
public static MvcHtmlString CheckBoxList <TModel, TItem, TValue, TKey>(HtmlHelper <TModel> htmlHelper, ModelMetadata modelMetadata, string listName, Expression <Func <TModel, IEnumerable <TItem> > > sourceDataExpr, Expression <Func <TItem, TValue> > valueExpr, Expression <Func <TItem, TKey> > textToDisplayExpr, Expression <Func <TItem, TKey> > htmlAttributesExpr, Expression <Func <TModel, IEnumerable <TItem> > > selectedValuesExpr, object htmlAttributes, HtmlListInfo htmlListInfo, string[] disabledValues, Position position = Position.Horizontal)
{
// validation
if (sourceDataExpr == null || sourceDataExpr.Body.ToString() == "null")
{
return(MvcHtmlString.Create(No_Data_Message));
}
if (htmlHelper.ViewData.Model == null)
{
throw new NoNullAllowedException(Empty_Model_Message);
}
if (listName.IsNullOrEmpty())
{
throw new ArgumentException(Empty_Name_Message, "listName");
}
// set properties
var model = htmlHelper.ViewData.Model;
var sourceData = sourceDataExpr.Compile()(model).ToList();
var valueFunc = valueExpr.Compile();
var textToDisplayFunc = textToDisplayExpr.Compile();
var selectedItems = new List <TItem>();
if (selectedValuesExpr != null)
{
var _selectedItems = selectedValuesExpr.Compile()(model);
if (_selectedItems != null)
{
selectedItems = _selectedItems.ToList();
}
}
var selectedValues = selectedItems.Select(s => valueFunc(s).ToString()).ToList();
// validate source data
if (!sourceData.Any())
{
return(MvcHtmlString.Create(No_Data_Message));
}
// set html properties for each checkbox from model object
Func <TItem, object, object> _valueHtmlAttributesFunc = (item, baseAttributes) => baseAttributes;
if (htmlAttributesExpr != null)
{
var valueHtmlAttributesFunc = htmlAttributesExpr.Compile();
_valueHtmlAttributesFunc = (item, baseAttributes) =>
{
var baseAttrDict = baseAttributes.ToDictionary();
var itemAttrDict = valueHtmlAttributesFunc(item).ToDictionary();
var result = new ExpandoObject();
var d = result as IDictionary <string, object>;
foreach (var pair in baseAttrDict.Concat(itemAttrDict))
{
d[pair.Key] = pair.Value;
}
return(result);
};
}
// if HtmlListInfo is provided, then check for inverse text direction
var textLayout = TextLayout.Default;
if (htmlListInfo != null && htmlListInfo.TextLayout == TextLayout.RightToLeft)
{
textLayout = htmlListInfo.TextLayout;
}
if (position == Position.Vertical_RightToLeft || position == Position.Horizontal_RightToLeft)
{
textLayout = TextLayout.RightToLeft;
}
// set up table/list html wrapper, if applicable
var numberOfItems = sourceData.Count;
var htmlWrapper = CreateHtmlWrapper(htmlListInfo, numberOfItems, position, textLayout);
// create checkbox list
var sb = new StringBuilder();
sb.Append(htmlWrapper.WrapOpen);
htmlwrapRowbreakCount = 0;
// create list of checkboxes based on data
foreach (var item in sourceData)
{
// get checkbox value and text
var itemValue = valueFunc(item).ToString();
var itemText = textToDisplayFunc(item).ToString();
// create checkbox element
sb = CreateCheckBoxListElement(sb, htmlHelper, modelMetadata, htmlWrapper, _valueHtmlAttributesFunc(item, htmlAttributes), selectedValues, disabledValues, listName, itemValue, itemText, textLayout);
}
sb.Append(htmlWrapper.WrapClose);
// return checkbox list
return(MvcHtmlString.Create(sb.ToString()));
}
/// <summary>
/// Creates an HTML wrapper for the checkbox list
/// </summary>
/// <param name="htmlListInfo">Settings for HTML wrapper of the list (e.g. 'new HtmlListInfo2(HtmlTag2.vertical_columns, 2, new { style="color:green;" })')</param>
/// <param name="numberOfItems">Count of all items in the list</param>
/// <param name="position">Direction of the list (e.g. 'Position2.Horizontal' or 'Position2.Vertical')</param>
/// <param name="textLayout">Sets layout of a checkbox for right-to-left languages</param>
/// <returns>HTML wrapper information</returns>
private static HtmlWrapperInfo CreateHtmlWrapper(HtmlListInfo htmlListInfo, int numberOfItems, Position position, TextLayout textLayout)
{
var htmlWrapInfo = new HtmlWrapperInfo();
if (htmlListInfo != null)
{
// creating custom layouts
switch (htmlListInfo.HtmlTag)
{
// creates user selected number of float sections with
// vertically sorted checkboxes
case HtmlTag.VerticalColumns:
{
if (htmlListInfo.Columns <= 0)
{
htmlListInfo.Columns = 1;
}
// calculate number of rows
var rows = Convert.ToInt32(Math.Ceiling(Convert.ToDecimal(numberOfItems)
/ Convert.ToDecimal(htmlListInfo.Columns)));
if (numberOfItems <= 4 &&
(numberOfItems <= htmlListInfo.Columns || numberOfItems - htmlListInfo.Columns == 1))
{
rows = numberOfItems;
}
htmlWrapInfo.SeparatorMaxCount = rows;
// create wrapped raw html tag
var wrapRow = HtmlElementTag.Div;
var wrapHtml_builder = new TagBuilder(wrapRow.ToString());
var user_html_attributes = htmlListInfo.HtmlAttributes.ToDictionary();
// create raw style and merge it with user provided style (if applicable)
var defaultSectionStyle = "float:left;"; // margin-right:30px; line-height:25px;
if (textLayout == TextLayout.RightToLeft)
{
defaultSectionStyle += " text-align: right;";
}
object style;
user_html_attributes.TryGetValue("style", out style);
if (style != null) // if user style is set, use it
{
wrapHtml_builder.MergeAttribute("style", defaultSectionStyle + " " + style);
}
else // if not set, add only default style
{
wrapHtml_builder.MergeAttribute("style", defaultSectionStyle);
}
// merge it with other user provided attributes (e.g.: class)
user_html_attributes.Remove("style");
wrapHtml_builder.MergeAttributes(user_html_attributes);
// build wrapped raw html tag
htmlWrapInfo.WrapOpen = wrapHtml_builder.ToString(TagRenderMode.StartTag);
htmlWrapInfo.WrapRowbreak = "</" + wrapRow + "> " +
wrapHtml_builder.ToString(TagRenderMode.StartTag);
htmlWrapInfo.WrapClose = wrapHtml_builder.ToString(TagRenderMode.EndTag) +
" <div style=\"clear:both;\"></div>";
htmlWrapInfo.AppendToElement = "<br/>";
}
break;
// creates an html <table> with checkboxes sorted horizontally
case HtmlTag.Table:
{
if (htmlListInfo.Columns <= 0)
{
htmlListInfo.Columns = 1;
}
htmlWrapInfo.SeparatorMaxCount = htmlListInfo.Columns;
var wrapHtml_builder = new TagBuilder(HtmlElementTag.Table.ToString());
wrapHtml_builder.MergeAttributes(htmlListInfo.HtmlAttributes.ToDictionary());
wrapHtml_builder.MergeAttribute("cellspacing", "0"); // for IE7 compatibility
var wrapRow = HtmlElementTag.Tr;
htmlWrapInfo.WrapElement = HtmlElementTag.Td;
htmlWrapInfo.WrapOpen = wrapHtml_builder.ToString(TagRenderMode.StartTag) +
"<" + wrapRow + ">";
htmlWrapInfo.WrapRowbreak = "</" + wrapRow + "><" + wrapRow + ">";
htmlWrapInfo.WrapClose = "</" + wrapRow + ">" +
wrapHtml_builder.ToString(TagRenderMode.EndTag);
}
break;
//// creates an html unordered (bulleted) list of checkboxes in one column
//case HtmlTag.Ul:
// {
// var wrapHtml_builder = new TagBuilder(htmlElementTag.ul.ToString());
// wrapHtml_builder.MergeAttributes(wrapInfo.htmlAttributes.ToDictionary());
// wrapHtml_builder.MergeAttribute("cellspacing", "0"); // for IE7 compatibility
// w.wrap_element = htmlElementTag.li;
// w.wrap_open = wrapHtml_builder.ToString(TagRenderMode.StartTag);
// w.wrap_close = wrapHtml_builder.ToString(TagRenderMode.EndTag);
// }
// break;
}
}
// default setting creates vertical or horizontal column of checkboxes
else
{
if (position == Position.Horizontal || position == Position.Horizontal_RightToLeft)
{
htmlWrapInfo.AppendToElement = " ";
}
if (position == Position.Vertical || position == Position.Vertical_RightToLeft)
{
htmlWrapInfo.AppendToElement = "<br/>";
}
if (textLayout == TextLayout.RightToLeft)
{
// lean text to right for right-to-left languages
var defaultSectionStyle = "style=\"text-align: right;\"";
var wrapRow = HtmlElementTag.Div;
htmlWrapInfo.WrapOpen = "<" + wrapRow + " " + defaultSectionStyle + ">";
htmlWrapInfo.WrapRowbreak = string.Empty;
htmlWrapInfo.WrapClose = "</" + wrapRow + ">";
}
}
// return completed check box list wrapper
return(htmlWrapInfo);
}
