[Adapdev-commits] Adapdev/src/Adapdev.NVelocity Template.cs,1.2,1.3

[Sean M. <int...@us...>]

Update of /cvsroot/adapdev/Adapdev/src/Adapdev.NVelocity
In directory sc8-pr-cvs1.sourceforge.net:/tmp/cvs-serv11770/src/Adapdev.NVelocity

Added Files:
	Template.cs 
Log Message:


--- NEW FILE: Template.cs ---
namespace NVelocity
{
	using System;
	using System.IO;
	using NVelocity.Context;
	using NVelocity.Exception;
	using NVelocity.Runtime.Parser;
	using NVelocity.Runtime.Parser.Node;
	using NVelocity.Runtime.Resource;

	/// <summary> This class is used for controlling all template
	/// operations. This class uses a parser created
	/// by JavaCC to create an AST that is subsequently
	/// traversed by a Visitor. 
	/// *
	/// <pre>
	/// Template template = Velocity.getTemplate("test.wm");
	/// Context context = new VelocityContext();
	/// *
	/// context.put("foo", "bar");
	/// context.put("customer", new Customer());
	/// *
	/// template.merge(context, writer);
	/// </pre>
	/// *
	/// </summary>
	/// <author> <a href="mailto:jv...@ap...">Jason van Zyl</a>
	/// </author>
	/// <author> <a href="mailto:ge...@op...">Geir Magnusson Jr.</a>
	/// </author>
	/// <version> $Id: Template.cs,v 1.3 2005/11/17 02:48:31 intesar66 Exp $
	/// 
	/// </version>
	public class Template : Resource
	{
		/// <summary>   To keep track of whether this template has been
		/// initialized. We use the document.init(context)
		/// to perform this.
		/// </summary>
		private bool initialized = false;

		private System.Exception errorCondition = null;

		/// <summary>Default constructor 
		/// </summary>
		public Template()
		{
		}

		/// <summary>  gets the named resource as a stream, parses and inits
		/// *
		/// </summary>
		/// <returns>true if successful
		/// @throws ResourceNotFoundException if template not found
		/// from any available source.
		/// @throws ParseErrorException if template cannot be parsed due
		/// to syntax (or other) error.
		/// @throws Exception some other problem, should only be from 
		/// initialization of the template AST.
		/// 
		/// </returns>
		public override bool Process()
		{
			data = null;
			Stream is_Renamed = null;
			errorCondition = null;

			/*
			*  first, try to get the stream from the loader
			*/
			try
			{
				is_Renamed = resourceLoader.getResourceStream(name);
			}
			catch (ResourceNotFoundException rnfe)
			{
				/*
				*  remember and re-throw
				*/

				errorCondition = rnfe;
				throw rnfe;
			}

			/*
			*  if that worked, lets protect in case a loader impl
			*  forgets to throw a proper exception
			*/

			if (is_Renamed != null)
			{
				/*
				*  now parse the template
				*/

				try
				{
					//UPGRADE_ISSUE: The equivalent of constructor 'java.io.BufferedReader.BufferedReader' is incompatible with the expected type in C#. 'ms-help://MS.VSCC/commoner/redir/redirect.htm?keyword="jlca1109"'
					StreamReader br = new StreamReader(new StreamReader(is_Renamed, System.Text.Encoding.GetEncoding(encoding)).BaseStream);

					data = rsvc.parse(br, name);
					InitDocument();
					return true;
				}
				catch (IOException uce)
				{
					String msg = "Template.process : Unsupported input encoding : " + encoding + " for template " + name;

					errorCondition = new ParseErrorException(msg);
					throw errorCondition;
				}
				catch (ParseException pex)
				{
					/*
					*  remember the error and convert
					*/

					errorCondition = new ParseErrorException(pex.Message);
					throw errorCondition;
				}
				catch (System.Exception e)
				{
					/*
					*  who knows?  Something from initDocument()
					*/

					errorCondition = e;
					throw e;
				}
				finally
				{
					/*
					*  Make sure to close the inputstream when we are done.
					*/
					is_Renamed.Close();
				}
			}
			else
			{
				/* 
				*  is == null, therefore we have some kind of file issue
				*/

				errorCondition = new ResourceNotFoundException("Unknown resource error for resource " + name);
				throw errorCondition;
			}
		}

		/// <summary>  initializes the document.  init() is not longer 
		/// dependant upon context, but we need to let the 
		/// init() carry the template name down throught for VM
		/// namespace features
		/// </summary>
		public virtual void InitDocument()
		{
			/*
			*  send an empty InternalContextAdapter down into the AST to initialize it
			*/

			InternalContextAdapterImpl ica = new InternalContextAdapterImpl(new VelocityContext());

			try
			{
				/*
				*  put the current template name on the stack
				*/

				ica.PushCurrentTemplateName(name);

				/*
				*  init the AST
				*/

				((SimpleNode) data).init(ica, rsvc);
			}
			finally
			{
				/*  
				*  in case something blows up...
				*  pull it off for completeness
				*/

				ica.PopCurrentTemplateName();
			}

		}

		/// <summary> The AST node structure is merged with the
		/// context to produce the final output. 
		/// *
		/// Throws IOException if failure is due to a file related
		/// issue, and Exception otherwise
		/// *
		/// </summary>
		/// <param name="context">Conext with data elements accessed by template
		/// </param>
		/// <param name="writer">output writer for rendered template
		/// @throws ResourceNotFoundException if template not found
		/// from any available source.
		/// @throws ParseErrorException if template cannot be parsed due
		/// to syntax (or other) error.
		/// @throws  Exception  anything else. 
		/// 
		/// </param>
		public virtual void Merge(IContext context, TextWriter writer)
		{
			/*
			*  we shouldn't have to do this, as if there is an error condition, 
			*  the application code should never get a reference to the 
			*  Template
			*/

			if (errorCondition != null)
			{
				throw errorCondition;
			}

			if (data != null)
			{
				/*
				*  create an InternalContextAdapter to carry the user Context down
				*  into the rendering engine.  Set the template name and render()
				*/

				InternalContextAdapterImpl ica = new InternalContextAdapterImpl(context);

				try
				{
					ica.PushCurrentTemplateName(name);
					ica.CurrentResource = this;

					((SimpleNode) data).render(ica, writer);
				}
				finally
				{
					/*
					*  lets make sure that we always clean up the context 
					*/
					ica.PopCurrentTemplateName();
					ica.CurrentResource = null;
				}
			}
			else
			{
				/*
				* this shouldn't happen either, but just in case.
				*/

				String msg = "Template.merge() failure. The document is null, " + "most likely due to parsing error.";

				rsvc.error(msg);
				throw new System.Exception(msg);
			}
		}
	}
}