poco/JSON/src/TemplateCache.cpp

//
// TemplateCache.cpp
//
// $Id$
//
// Library: JSON
// Package: JSON
// Module:  TemplateCache
//
// Copyright (c) 2012, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// Permission is hereby granted, free of charge, to any person or organization
// obtaining a copy of the software and accompanying documentation covered by
// this license (the "Software") to use, reproduce, display, distribute,
// execute, and transmit the Software, and to prepare derivative works of the
// Software, and to permit third-parties to whom the Software is furnished to
// do so, all subject to the following:
//
// The copyright notices in the Software and this entire statement, including
// the above license grant, this restriction and the following disclaimer,
// must be included in all copies of the Software, in whole or in part, and
// all derivative works of the Software, unless such copies or derivative
// works are solely in the form of machine-executable object code generated by
// a source language processor.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
// SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
// FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
// ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.
//


#include "Poco/File.h"
#include "Poco/JSON/TemplateCache.h"


namespace Poco {
namespace JSON {


TemplateCache* TemplateCache::_instance = NULL;


TemplateCache::TemplateCache() : _logger(NULL)
{
	setup();
}


TemplateCache::~TemplateCache()
{
	_instance = NULL;
}

void TemplateCache::setup()
{
	poco_assert (_instance == NULL);
	_instance = this;
}


Template::Ptr TemplateCache::getTemplate(const Path& path)
{
	if ( _logger )
	{
		poco_trace_f1(*_logger, "Trying to load %s", path.toString());
	}
	Path templatePath = resolvePath(path);
	std::string templatePathname = templatePath.toString();
	if ( _logger )
	{
		poco_trace_f1(*_logger, "Path resolved to %s", templatePathname);
	}
	File templateFile(templatePathname);

	Template::Ptr tpl;

	std::map<std::string, Template::Ptr>::iterator it = _cache.find(templatePathname);
	if ( it == _cache.end() )
	{
		if ( templateFile.exists() )
		{
			if ( _logger )
			{
				poco_information_f1(*_logger, "Loading template %s", templatePath.toString());
			}

			tpl = new Template(templatePath);

			try
			{
				tpl->parse();
				_cache[templatePathname] = tpl;
			}
			catch(JSONTemplateException& jte)
			{
				if ( _logger )
				{
					poco_error_f2(*_logger, "Template %s contains an error: %s", templatePath.toString(), jte.message());
				}
			}
		}
		else
		{
			if ( _logger )
			{
				poco_error_f1(*_logger, "Template file %s doesn't exist", templatePath.toString());
			}
			throw FileNotFoundException(templatePathname);
		}
	}
	else
	{
		tpl = it->second;
		if ( tpl->parseTime() < templateFile.getLastModified() )
		{
			if ( _logger )
			{
				poco_information_f1(*_logger, "Reloading template %s", templatePath.toString());
			}

			tpl = new Template(templatePath);

			try
			{
				tpl->parse();
				_cache[templatePathname] = tpl;
			}
			catch(JSONTemplateException& jte)
			{
				if ( _logger )
				{
					poco_error_f2(*_logger, "Template %s contains an error: %s", templatePath.toString(), jte.message());
				}
			}
		}
	}

	return tpl;
}


Path TemplateCache::resolvePath(const Path& path) const
{
	if ( path.isAbsolute() )
		return path;

	for(std::vector<Path>::const_iterator it = _includePaths.begin(); it != _includePaths.end(); ++it)
	{
		Path templatePath(*it, path);

		File templateFile(templatePath);
		if ( templateFile.exists() )
		{
			if ( _logger )
			{
				poco_trace_f2(*_logger, "%s template file resolved to %s", path.toString(), templatePath.toString());
			}
			return templatePath;
		}
		if ( _logger )
		{
			poco_trace_f1(*_logger, "%s doesn't exist", templatePath.toString());
		}
	}

	throw FileNotFoundException(path.toString());
}


} } // Poco::JSON