/// <summary>
/// Generates the HTML markup corresponding to a list of checkboxes.
/// </summary>
/// <typeparam name="TModel">The type of the model</typeparam>
/// <typeparam name="T">The type of the elements of the enumeration. Use simple types</typeparam>
/// <param name="htmlHelper"></param>
/// <param name="expression">The lambda expression that yields an enumeration of Ts</param>
/// <param name="namePrefix">Prefix to be used by the name for the generated checkboxes</param>
/// <param name="items">List of available options to be displayed</param>
/// <param name="htmlAttributes">An object whose properties will become attributes for the HTML main container element</param>
/// <param name="cols">Number of columns in which the list will be arranged. Valid values range lies between 1 and 12</param>
/// <returns></returns>
public static MvcHtmlString MultiSelectFor<TModel, T>(
this HtmlHelper<TModel> htmlHelper,
Expression<Func<TModel, IEnumerable<T>>> expression,
IEnumerable<SelectListItem> items,
object htmlAttributes,
int cols = 1 ) {
cols = (cols < 1 || cols > 12) ? 1 : cols;
int rows = items.Count() % cols == 0 ? items.Count() / cols : 1 + items.Count() / cols;
TagBuilder mainContainer = new TagBuilder("div");
if(htmlAttributes != null) {
foreach(PropertyInfo prop in htmlAttributes.GetType().GetProperties()) {
mainContainer.Attributes.Add(prop.Name, prop.GetValue(htmlAttributes).ToString());
}
}
TagBuilder grid = new TagBuilder("div");
grid.Attributes.Add("style", $"display: grid; grid.template-columns: {cols}; grid-template-rows: {rows}");
ModelMetadata modelMetadata = ModelMetadata.FromLambdaExpression(expression, htmlHelper.ViewData);
string prefix = htmlHelper.ViewData.TemplateInfo.HtmlFieldPrefix;
string cboxName = String.IsNullOrWhiteSpace(prefix) ?
modelMetadata.PropertyName :
$"{prefix}.{modelMetadata.PropertyName}";
int index = 0;
StringBuilder gridContentBuilder = new StringBuilder();
foreach(SelectListItem item in items) {
int currentCol = 1 + index % cols;
int currentRow = 1 + index / cols;
TagBuilder div = new TagBuilder("div");
div.Attributes.Add("style", $"grid-column-start: {currentCol}; grid-row-start: {currentRow}");
TagBuilder checkbox = new TagBuilder("input");
checkbox.Attributes.Add("type", "checkbox");
checkbox.Attributes.Add("name", cboxName);
checkbox.Attributes.Add("value", item.Value);
if(item.Selected) {
checkbox.Attributes.Add("checked", "checked");
}
checkbox.GenerateId($"{cboxName}_{item.Value}");
TagBuilder label = new TagBuilder("label");
label.Attributes.Add("for", checkbox.Attributes["id"]);
label.SetInnerText(item.Text);
StringBuilder stringBuilder = new StringBuilder();
stringBuilder.AppendLine(checkbox.ToString(TagRenderMode.SelfClosing));
stringBuilder.AppendLine(label.ToString(TagRenderMode.Normal));
div.InnerHtml = stringBuilder.ToString();
gridContentBuilder.AppendLine(div.ToString(TagRenderMode.Normal));
index++;
}
grid.InnerHtml = gridContentBuilder.ToString();
mainContainer.InnerHtml = grid.ToString(TagRenderMode.Normal);
return new MvcHtmlString(mainContainer.ToString(TagRenderMode.Normal));
}
private static MvcHtmlString CKEditorHelper(HtmlHelper htmlHelper, ModelMetadata modelMetadata, string name, string uploadUrl, IDictionary <string, object> rowsAndColumns, IDictionary <string, object> htmlAttributes, string ckEditorConfigOptions)
{
var fullName = htmlHelper.ViewContext.ViewData.TemplateInfo.GetFullHtmlFieldName(name);
var id = htmlHelper.ViewContext.ViewData.TemplateInfo.GetFullHtmlFieldId(name);
var textAreaBuilder = new TagBuilder("textarea");
textAreaBuilder.GenerateId(fullName);
textAreaBuilder.MergeAttributes(htmlAttributes, true);
textAreaBuilder.MergeAttribute("name", fullName, true);
var style = "";
if (textAreaBuilder.Attributes.ContainsKey("style"))
{
style = textAreaBuilder.Attributes["style"];
}
if (string.IsNullOrWhiteSpace(style))
{
style = "";
}
//style += string.Format("height:{0}em; width:{1}em; margin-bottom: 20px !important;", rowsAndColumns["rows"], rowsAndColumns["cols"]);
style += string.Format("height:{0}em; width:100%; margin-bottom: 20px !important;", rowsAndColumns["rows"], rowsAndColumns["cols"]);
textAreaBuilder.MergeAttribute("style", style, true);
// If there are any errors for a named field, we add the CSS attribute.
if (htmlHelper.ViewData.ModelState.TryGetValue(fullName, out ModelState modelState) && modelState.Errors.Count > 0)
{
textAreaBuilder.AddCssClass(HtmlHelper.ValidationInputCssClassName);
}
textAreaBuilder.MergeAttributes(htmlHelper.GetUnobtrusiveValidationAttributes(name));
string value;
if (modelState?.Value != null)
{
value = modelState.Value.AttemptedValue;
}
else if (modelMetadata.Model != null)
{
value = modelMetadata.Model.ToString();
}
else
{
value = string.Empty;
}
// The first newline is always trimmed when a TextArea is rendered, so we add an extra one
// in case the value being rendered is something like "\r\nHello".
textAreaBuilder.SetInnerText(Environment.NewLine + value);
var scriptBuilder = new TagBuilder("script");
scriptBuilder.MergeAttribute("type", "text/javascript");
if (string.IsNullOrEmpty(ckEditorConfigOptions))
{
ckEditorConfigOptions = string.Format("{{ width:'100%', height:'{1}em', filebrowserImageUploadUrl:'{2}' }}", rowsAndColumns["cols"], rowsAndColumns["rows"], uploadUrl);
}
if (!ckEditorConfigOptions.Trim().StartsWith("{"))
{
ckEditorConfigOptions = "{" + ckEditorConfigOptions;
}
if (!ckEditorConfigOptions.Trim().EndsWith("}"))
{
ckEditorConfigOptions += "}";
}
scriptBuilder.InnerHtml = string.Format(" $('#{0}').ckeditor({1}).addClass('{2}'); ", id, ckEditorConfigOptions, CK_Ed_Class);
//<script type=""text/javascript""> function UpdateCKEditors() { $('." + CK_Ed_Class + @"').ckeditorGet().updateElement(); } </script>"
htmlHelper.ScriptFileSingle(@"<script src=""" + CK_Ed_Location + @"ckeditor.js""></script>");
htmlHelper.ScriptFileSingle(@"<script src=""" + CK_Ed_Location + @"adapters/jquery.js""></script>");
htmlHelper.Script(scriptBuilder.ToString());
return(MvcHtmlString.Create(@"
<div class=""form-group"">
<div class=""col-sm-12"">
" + textAreaBuilder + @"
</div>
</div>"));
}
private static MvcHtmlString CKEditorHelper(HtmlHelper htmlHelper, ModelMetadata modelMetadata, string name, IDictionary <string, object> rowsAndColumns, IDictionary <string, object> htmlAttributes, string ckEditorConfigOptions)
{
string fullName = htmlHelper.ViewContext.ViewData.TemplateInfo.GetFullHtmlFieldName(name);
if (String.IsNullOrEmpty(fullName))
{
throw new ArgumentException("string parameter is null or empty", "name");
}
TagBuilder textAreaBuilder = new TagBuilder("textarea");
textAreaBuilder.GenerateId(fullName);
textAreaBuilder.MergeAttributes(htmlAttributes, true);
textAreaBuilder.MergeAttribute("name", fullName, true);
string style = "";
if (textAreaBuilder.Attributes.ContainsKey("style"))
{
style = textAreaBuilder.Attributes["style"];
}
if (string.IsNullOrWhiteSpace(style))
{
style = "";
}
style += string.Format("height:{0}em; width:{1}em;", rowsAndColumns["rows"], rowsAndColumns["cols"]);
textAreaBuilder.MergeAttribute("style", style, true);
// If there are any errors for a named field, we add the CSS attribute.
ModelState modelState;
if (htmlHelper.ViewData.ModelState.TryGetValue(fullName, out modelState) && modelState.Errors.Count > 0)
{
textAreaBuilder.AddCssClass(HtmlHelper.ValidationInputCssClassName);
}
textAreaBuilder.MergeAttributes(htmlHelper.GetUnobtrusiveValidationAttributes(name));
string value;
if (modelState != null && modelState.Value != null)
{
value = modelState.Value.AttemptedValue;
}
else if (modelMetadata.Model != null)
{
value = modelMetadata.Model.ToString();
}
else
{
value = String.Empty;
}
// The first newline is always trimmed when a TextArea is rendered, so we add an extra one
// in case the value being rendered is something like "\r\nHello".
textAreaBuilder.SetInnerText(Environment.NewLine + value);
TagBuilder scriptBuilder = new TagBuilder("script");
scriptBuilder.MergeAttribute("type", "text/javascript");
if (string.IsNullOrEmpty(ckEditorConfigOptions))
{
ckEditorConfigOptions = string.Format("{{ width:'{0}em', height:'{1}em', CKEDITOR.config.allowedContent : true }}", rowsAndColumns["cols"], rowsAndColumns["rows"]);
}
if (!ckEditorConfigOptions.Trim().StartsWith("{"))
{
ckEditorConfigOptions = "{" + ckEditorConfigOptions;
}
if (!ckEditorConfigOptions.Trim().EndsWith("}"))
{
ckEditorConfigOptions += "}";
}
scriptBuilder.InnerHtml = string.Format(" $('#{0}').ckeditor({1}).addClass('{2}'); ",
fullName,
ckEditorConfigOptions,
CK_Ed_Class
);
return(MvcHtmlString.Create(textAreaBuilder.ToString() + "\n" + scriptBuilder.ToString()));
}