I have a server-side control which renders as <input type="Something"> or <textarea>. The code is self-explanatory:
public string Namespace
{
get { return nspace; }
set { nspace = value; }
}
public string Model
{
get { return model; }
set { model = value; }
}
public string Text
{
get { return text; }
set { text = value; }
}
public string TextMode
{
get { return textMode; }
set { textMode = value; }
}
public string _Type
{
get { return type; }
set { type = value; }
}
public string Property { get; set; }
protected override void RenderContents(HtmlTextWriter output)
{
output.AddAttribute(HtmlTextWriterAttribute.Id, Property.ToLower());
output.AddAttribute(HtmlTextWriterAttribute.Name, Property.ToLower());
output.AddAttribute(HtmlTextWriterAttribute.Type, _Type);
if(!String.IsNullOrEmpty(Text))
output.AddAttribute(HtmlTextWriterAttribute.Value, Text);
Type modelType = Type.GetType(string.Format("{0}.{1}", Namespace, Model));
PropertyInfo propInfo = modelType.GetProperty(Property);
var attr = propInfo.GetCustomAttribute<RequiredAttribute>(false);
if (attr != null)
{
output.AddAttribute("data-val", "true");
output.AddAttribute("data-val-required", attr.ErrorMessage);
}
//forces styles to be added to the control
this.AddAttributesToRender(output);
if (!String.IsNullOrEmpty(TextMode))
{
output.RenderBeginTag("textarea");
output.RenderEndTag();
}
else
{
output.RenderBeginTag("input");
output.RenderEndTag();
}
}
This control is aimed at getting validation error messages from Data Model (instead of providing "data-val" and "data-val-required" to every textbox). using this code is easy:
<ServerControlTag:ControlName Property="aProp" runat="Server" Model="MyModel" ID="txtSomething" />
Which renders as a input type=text tag, and the following renders as a textarea tag:
<ServerControlTag:ControlName Property="Description" runat="Server" Model="MyModel" TextMode="MultiLine" ID="txtDescription" class="message" />
My problem is when rendering textarea I cannot find any attribute to fill the text of textarrea. To set text in a textarea I have just found the following syntax:
<textarea ... > My Text Here </textarea>
yet, I don't know how to implement it in my server control. I don't know even if I am on the right track.
You need to call the normal
Write()
method to write text inside the tag.Remember to HTML-encode the text.