/// <summary>
/// Handle the related attribute types which exist upon the element exposed by the given context, if any.
/// </summary>
/// <returns>A response type providing information about the result of this operation.</returns>
/// <param name="context">The rendering context, which exposes a ZPT element.</param>
public AttributeHandlingResult Handle(IRenderingContext context)
{
if(context == null)
{
throw new ArgumentNullException(nameof(context));
}
AttributeHandlingResult output;
var attrib = context.GetTalAttribute(ZptConstants.Tal.OmitTagAttribute);
if(attrib != null)
{
if(attrib.Value.Length == 0)
{
var children = context.Element.Omit();
output = new AttributeHandlingResult(new RenderingContext[0],
false,
children.Select(x => context.CreateSiblingContext(x)).ToArray());
}
else
{
// Normal handling by detecting an attribute and using its value
var result = context.TalModel.Evaluate(attrib.Value, context);
if(!result.CancelsAction && result.GetValueAsBoolean())
{
var children = context.Element.Omit();
output = new AttributeHandlingResult(new RenderingContext[0],
false,
children.Select(x => context.CreateSiblingContext(x)).ToArray());
}
else
{
output = new AttributeHandlingResult(new [] { context }, true);
}
}
}
else
{
output = new AttributeHandlingResult(new [] { context }, true);
}
return output;
}
/// <summary>
/// Handle the related attribute types which exist upon the element exposed by the given context, if any.
/// </summary>
/// <returns>A response type providing information about the result of this operation.</returns>
/// <param name="context">The rendering context, which exposes a ZPT element.</param>
public AttributeHandlingResult Handle(IRenderingContext context)
{
if(context == null)
{
throw new ArgumentNullException(nameof(context));
}
AttributeHandlingResult output;
var attrib = context.GetTalAttribute(ZptConstants.Tal.OnErrorAttribute);
if(attrib != null)
{
string mode;
var expressionResult = this.GetAttributeResult(attrib, context, out mode);
if(expressionResult.CancelsAction)
{
output = new AttributeHandlingResult(new [] { context }, true);
}
else if(expressionResult.Value == null)
{
context.Element.RemoveAllChildren();
output = new AttributeHandlingResult(new [] { context }, true);
}
else
{
context.Element.ReplaceChildrenWith(expressionResult.GetValue<string>(),
mode == STRUCTURE_INDICATOR);
output = new AttributeHandlingResult(new [] { context }, true);
}
ZptConstants.TraceSource.TraceInformation(Resources.LogMessageFormats.TalErrorHandled,
context.Element.GetFullFilePathAndLocation(),
nameof(OnErrorAttributeHandler),
nameof(Handle));
}
else
{
output = new AttributeHandlingResult(new [] { context }, true);
}
return output;
}
/// <summary>
/// Handle the related attribute types which exist upon the element exposed by the given context, if any.
/// </summary>
/// <returns>A response type providing information about the result of this operation.</returns>
/// <param name="context">The rendering context, which exposes a ZPT element.</param>
public AttributeHandlingResult Handle(IRenderingContext context)
{
if(context == null)
{
throw new ArgumentNullException(nameof(context));
}
AttributeHandlingResult output = new AttributeHandlingResult(new [] { context }, true);
var attribute = context.GetTalAttribute(ZptConstants.Tal.ConditionAttribute);
if(attribute != null)
{
ExpressionResult result;
try
{
result = context.TalModel.Evaluate(attribute.Value, context);
}
catch(Exception ex)
{
string message = String.Format(ExceptionMessages.ExpressionEvaluationException,
ZptConstants.Tal.Namespace,
ZptConstants.Tal.ConditionAttribute,
attribute.Value,
context.Element.Name);
throw new ModelEvaluationException(message, ex) {
ExpressionText = attribute.Value,
ElementName = context.Element.Name,
};
}
var removeElement = result.CancelsAction? false : !result.GetValueAsBoolean();
if(removeElement)
{
context.Element.Remove();
output = new AttributeHandlingResult(new RenderingContext[0], false);
}
}
return output;
}
/// <summary>
/// Handle the related attribute types which exist upon the element exposed by the given context, if any.
/// </summary>
/// <returns>A response type providing information about the result of this operation.</returns>
/// <param name="context">The rendering context, which exposes a ZPT element.</param>
public AttributeHandlingResult Handle(IRenderingContext context)
{
if(context == null)
{
throw new ArgumentNullException(nameof(context));
}
AttributeHandlingResult output;
string attribName;
var attrib = this.GetAttribute(context, out attribName);
if(attrib != null)
{
string mode;
var expressionResult = this.GetAttributeResult(attrib, context, out mode);
if(expressionResult.CancelsAction && attribName == ZptConstants.Tal.ContentAttribute)
{
output = new AttributeHandlingResult(new [] { context }, true);
}
else if(expressionResult.CancelsAction && attribName == ZptConstants.Tal.ReplaceAttribute)
{
var children = context.Element.Omit();
output = new AttributeHandlingResult(new RenderingContext[0],
false,
children.Select(x => context.CreateSiblingContext(x)).ToArray());
}
else if(expressionResult.Value == null)
{
if(attribName == ZptConstants.Tal.ContentAttribute)
{
context.Element.RemoveAllChildren();
output = new AttributeHandlingResult(new [] { context }, true);
}
else
{
context.Element.Remove();
output = new AttributeHandlingResult(new RenderingContext[0], false);
}
}
else
{
if(attribName == ZptConstants.Tal.ContentAttribute)
{
var resultValue = expressionResult.GetValue<object>();
context.Element.ReplaceChildrenWith((resultValue?? String.Empty).ToString(),
mode == STRUCTURE_INDICATOR);
output = new AttributeHandlingResult(new [] { context }, true);
}
else
{
var resultValue = expressionResult.GetValue<object>();
var elements = context.Element.ReplaceWith((resultValue?? String.Empty).ToString(),
mode == STRUCTURE_INDICATOR);
output = new AttributeHandlingResult(elements.Select(x => context.CreateSiblingContext(x, true)).ToArray(), true);
}
}
}
else
{
output = new AttributeHandlingResult(new [] { context }, true);
}
return output;
}