/// <summary>
/// Implementation of OnPreRender that links the Validator in the page with javascript code
/// </summary>
/// <param name="e"></param>
protected override void OnPreRender(EventArgs e)
{
base.OnPreRender(e);
ClientScriptManager cm = Page.ClientScript;
BaseValidator extendedValidator = this.GetExtendedValidator();
CustomValidator customValidator = extendedValidator as CustomValidator;
if (extendedValidator != null)
{
if (customValidator != null)
{
customValidator.ClientValidationFunction = "CustomServerSideValidationEvaluateIsValid";
}
else
{
string controlId = extendedValidator.ClientID;
cm.RegisterExpandoAttribute(controlId, "evaluationfunction", "GenericServerSideValidationEvaluateIsValid", false);
}
}
//Call GetCallbackEventReference to be able to do a Callback on the client-side
cm.GetCallbackEventReference(this, "arg", "ServerSideValidationValidate", "context");
//Registers this control as one that requires postback handling when the page is posted back to the server.
//This is to prevent full page validation when the postback is in fact a callback triggered by this control
this.Page.RegisterRequiresPostBack(this);
}
/// <summary>
/// Adds the attributes to render.
/// </summary>
/// <param name="writer"></param>
protected override void AddAttributesToRender(HtmlTextWriter writer)
{
base.AddAttributesToRender(writer);
if (this.EnableClientScript)
{
ClientScriptManager csm = this.Page.ClientScript;
// Build the argument which will be passed to the server when the callback happens.
string argument = String.Format("ValidatorGetValue({0}.controltovalidate)", this.ClientID);
// The actual callback function.
string callbackFunction = csm.GetCallbackEventReference(this, argument, "__callbackValidatorCallback", "'" + this.ClientID + "'");
csm.RegisterExpandoAttribute(this.ClientID, "evaluationfunction", "CustomValidatorEvaluateIsValid", false);
csm.RegisterExpandoAttribute(this.ClientID, "clientvalidationfunction", "__callbackValidatorValidate", false);
csm.RegisterExpandoAttribute(this.ClientID, "callbackfunction", callbackFunction, false);
if (this.ValidateEmptyText)
{
csm.RegisterExpandoAttribute(this.ClientID, "validateemptytext", "true", false);
}
}
}
public static void RegisterExpandAttribute(Page p)
{
ClientScriptManager cs = p.ClientScript;
cs.RegisterExpandoAttribute("Message", "title", "New title from client script.", true);
}
/// <summary>
/// Registers a name/value pair as a custom (expando) attribute of the specified control given a control ID, attribute name, and attribute value.
/// </summary>
/// <param name="controlId">The <see cref="T:System.Web.UI.Control"/> on the page that contains the custom attribute.
/// </param><param name="attributeName">The name of the custom attribute to register.
/// </param><param name="attributeValue">The value of the custom attribute.
/// </param>
public void RegisterExpandoAttribute(string controlId, string attributeName, string attributeValue)
{
_clientScriptManager.RegisterExpandoAttribute(controlId, attributeName, attributeValue);
}
