/// <summary>
/// Renders the input reader using the context into the output writer.
/// To be used when a template is dynamically constructed, or want to
/// use Velocity as a token replacer.
/// </summary>
/// <param name="context">context to use in rendering input string
/// </param>
/// <param name="out"> Writer in which to render the output
/// </param>
/// <param name="logTag"> string to be used as the template name for log messages
/// in case of error
/// </param>
/// <param name="reader">Reader containing the VTL to be rendered
/// </param>
/// <returns>true if successful, false otherwise. If false, see
/// Velocity runtime log
/// @since Velocity v1.1
/// </returns>
public bool Evaluate(IContext context, TextWriter writer, String logTag, TextReader reader)
{
SimpleNode nodeTree = null;
try
{
nodeTree = ri.parse(reader, logTag);
}
catch (ParseException pex)
{
throw new ParseErrorException(pex.Message);
}
/*
* now we want to init and render
*/
if (nodeTree != null)
{
InternalContextAdapterImpl ica = new InternalContextAdapterImpl(context);
ica.PushCurrentTemplateName(logTag);
try
{
try
{
nodeTree.init(ica, ri);
}
catch (Exception e)
{
ri.error("Velocity.evaluate() : init exception for tag = " + logTag + " : " + e);
}
/*
* now render, and let any exceptions fly
*/
nodeTree.render(ica, writer);
}
finally
{
ica.PopCurrentTemplateName();
}
return(true);
}
return(false);
}