echopointng.template.TemplateDataSource Maven / Gradle / Ivy
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package echopointng.template;
/*
* This file is part of the Echo Point Project. This project is a collection
* of Components that have extended the Echo Web Application Framework.
*
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* Alternatively, the contents of this file may be used under the terms of
* either the GNU General Public License Version 2 or later (the "GPL"), or
* the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*/
import java.io.IOException;
import java.io.InputStream;
/**
* TemplateDataSource is used to return template source data and
* encoding information for this data.
*
* A single TemplateDataSource can be used as the source for
* multiple TemplatePanels. This helps reduce the memory footprint of the
* template data. An implementation of this interface must keep the requirement
* in mind.
*/
public interface TemplateDataSource {
/**
* Returns a canonical name of this TemplateDataSource.
*
* The name returned here is used to look up the parsing result of the
* internal caching, so it should differ for all different
* TemplateDataSource objects :-)
*
* May return null if this TemplateDataSource is supposed to
* be parsed each time. The canonical name would be something like a
* filename or an URL.
*
* @return a unique name of the TemplateDataSource
*/
public String getCanonicalName();
/**
* This content type of the template data is used by the rendering framework
* to find an appropriate template compiler.
*
* An example content type is text/xhtml and cause a template compiler to be
* found for XHTML template data.
*
* @return the content type of the template data
*/
public String getContentType();
/**
* This returns the character encoding of the
* TemplateDataSource.
*
* This will be used to create a
* new InputStreamReader(stream,characterEncoding) from the
* InputStream return by getInputStream().
*
* @return the character encoding of the TemplateDataSource
* as defined by the java.io.InputStreamReader()
* specification.
*
* @see java.io.InputStreamReader#InputStreamReader(java.io.InputStream,
* java.lang.String)
*/
public String getCharacterEncoding();
/**
* Gets an InputStream of this
* TemplateDataSource.
*
* Note that this method may be called multiple times in the life
* of the TemplateDataSource. So you probably have to
* implement a buffer if your underlying data source is transient ..
*
* @return a InputStream containing the template data
*/
public InputStream getInputStream() throws IOException;
/**
* This returns a hint to the template rendering mechanism as to whether
* this template data can be cached. If null is returned then
* the template data will never be cached.
*
* However the inverse is not necessarily the case. You may return a
* TemplateCachingHints, however this does not mean the
* rendering mechanism will cache the template data.
*
* You might return null if the template data is especially
* large and you dont want it retained in cache memory.
*
* @return null if the template data should not be cached or a
* TemplateCachingHints to say how it might
* be cached.
*/
public TemplateCachingHints getCachingHints();
/**
* This returns a hint to the underlying template compiler mechanism as to
* how the template data should be compiled into XHTML.
*
* Most of the TemplateCompilerHints properties are really
* aimed as JAXP XML parser implementations but you can provide generic
* values via the getAttribute() mechanism.
*
* @return a TemplateCompilerHints implementation or null
* if there are no compiler hints
*/
public TemplateCompilerHints getCompilerHints();
}