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package org.apache.velocity.runtime;
/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
import org.apache.velocity.Template;
import org.apache.velocity.app.event.EventCartridge;
import org.apache.velocity.context.Context;
import org.apache.velocity.exception.MethodInvocationException;
import org.apache.velocity.exception.ParseErrorException;
import org.apache.velocity.exception.ResourceNotFoundException;
import org.apache.velocity.runtime.RuntimeConstants.SpaceGobbling;
import org.apache.velocity.runtime.directive.Directive;
import org.apache.velocity.runtime.directive.Macro;
import org.apache.velocity.runtime.parser.LogContext;
import org.apache.velocity.runtime.parser.ParseException;
import org.apache.velocity.runtime.parser.Parser;
import org.apache.velocity.runtime.parser.node.Node;
import org.apache.velocity.runtime.parser.node.SimpleNode;
import org.apache.velocity.runtime.resource.ContentResource;
import org.apache.velocity.util.ExtProperties;
import org.apache.velocity.util.introspection.Uberspect;
import org.slf4j.Logger;
import java.io.Reader;
import java.io.Writer;
import java.util.List;
import java.util.Properties;
/**
* Interface for internal runtime services that are needed by the
* various components w/in Velocity. This was taken from the old
* Runtime singleton, and anything not necessary was removed.
*
* Currently implemented by RuntimeInstance.
*
* @author Geir Magusson Jr.
* @version $Id$
*/
public interface RuntimeServices
{
/**
* This is the primary initialization method in the Velocity
* Runtime. The systems that are setup/initialized here are
* as follows:
*
*
* - Logging System
* - ResourceManager
* - Parser Pool
* - Global Cache
* - Static Content Include System
* - Velocimacro System
*
*/
void init();
/**
* Allows an external system to set a property in
* the Velocity Runtime.
*
* @param key property key
* @param value property value
*/
void setProperty(String key, Object value);
/**
* Allow an external system to set an ExtProperties
* object to use.
*
* @param configuration
* @since 2.0
*/
void setConfiguration(ExtProperties configuration);
/**
* Add a property to the configuration. If it already
* exists then the value stated here will be added
* to the configuration entry. For example, if
*
* resource.loader = file
*
* is already present in the configuration and you
*
* addProperty("resource.loader", "classpath")
*
* Then you will end up with a Vector like the
* following:
*
* ["file", "classpath"]
*
* @param key
* @param value
*/
void addProperty(String key, Object value);
/**
* Clear the values pertaining to a particular
* property.
*
* @param key of property to clear
*/
void clearProperty(String key);
/**
* Allows an external caller to get a property. The calling
* routine is required to know the type, as this routine
* will return an Object, as that is what properties can be.
*
* @param key property to return
* @return The value.
*/
Object getProperty(String key);
/**
* Initialize the Velocity Runtime with a Properties
* object.
*
* @param p
*/
void init(Properties p);
/**
* Initialize the Velocity Runtime with the name of
* ExtProperties object.
*
* @param configurationFile
*/
void init(String configurationFile);
/**
* Parse the input and return the root of
* AST node structure.
*
* In the event that it runs out of parsers in the
* pool, it will create and let them be GC'd
* dynamically, logging that it has to do that. This
* is considered an exceptional condition. It is
* expected that the user will set the
* PARSER_POOL_SIZE property appropriately for their
* application. We will revisit this.
*
* @param reader inputstream retrieved by a resource loader
* @param template template being parsed
* @return The AST representing the template.
* @throws ParseException
*/
SimpleNode parse(Reader reader, Template template)
throws ParseException;
/**
* Renders the input string 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.
*
* @param context context to use in rendering input string
* @param out Writer in which to render the output
* @param logTag string to be used as the template name for log
* messages in case of error
* @param instring input string containing the VTL to be rendered
*
* @return true if successful, false otherwise. If false, see
* Velocity runtime log
* @throws ParseErrorException The template could not be parsed.
* @throws MethodInvocationException A method on a context object could not be invoked.
* @throws ResourceNotFoundException A referenced resource could not be loaded.
* @since Velocity 1.6
*/
boolean evaluate(Context context, Writer out,
String logTag, String instring);
/**
* 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.
*
* @param context context to use in rendering input string
* @param writer Writer in which to render the output
* @param logTag string to be used as the template name for log messages
* in case of error
* @param reader Reader containing the VTL to be rendered
*
* @return true if successful, false otherwise. If false, see
* Velocity runtime log
* @throws ParseErrorException The template could not be parsed.
* @throws MethodInvocationException A method on a context object could not be invoked.
* @throws ResourceNotFoundException A referenced resource could not be loaded.
* @since Velocity 1.6
*/
boolean evaluate(Context context, Writer writer,
String logTag, Reader reader);
/**
* Invokes a currently registered Velocimacro with the params provided
* and places the rendered stream into the writer.
*
* Note : currently only accepts args to the VM if they are in the context.
*
* @param vmName name of Velocimacro to call
* @param logTag string to be used for template name in case of error. if null,
* the vmName will be used
* @param params keys for args used to invoke Velocimacro, in java format
* rather than VTL (eg "foo" or "bar" rather than "$foo" or "$bar")
* @param context Context object containing data/objects used for rendering.
* @param writer Writer for output stream
* @return true if Velocimacro exists and successfully invoked, false otherwise.
* @since 1.6
*/
boolean invokeVelocimacro(final String vmName, String logTag,
String[] params, final Context context,
final Writer writer);
/**
* Returns a Template from the resource manager.
* This method assumes that the character encoding of the
* template is set by the input.encoding
* property. The default is UTF-8.
*
* @param name The file name of the desired template.
* @return The template.
* @throws ResourceNotFoundException if template not found
* from any available source.
* @throws ParseErrorException if template cannot be parsed due
* to syntax (or other) error.
*/
Template getTemplate(String name)
throws ResourceNotFoundException, ParseErrorException;
/**
* Returns a Template from the resource manager
*
* @param name The name of the desired template.
* @param encoding Character encoding of the template
* @return The template.
* @throws ResourceNotFoundException if template not found
* from any available source.
* @throws ParseErrorException if template cannot be parsed due
* to syntax (or other) error.
*/
Template getTemplate(String name, String encoding)
throws ResourceNotFoundException, ParseErrorException;
/**
* Returns a static content resource from the
* resource manager. Uses the current value
* if INPUT_ENCODING as the character encoding.
*
* @param name Name of content resource to get
* @return parsed ContentResource object ready for use
* @throws ResourceNotFoundException if template not found
* from any available source.
* @throws ParseErrorException
*/
ContentResource getContent(String name)
throws ResourceNotFoundException, ParseErrorException;
/**
* Returns a static content resource from the
* resource manager.
*
* @param name Name of content resource to get
* @param encoding Character encoding to use
* @return parsed ContentResource object ready for use
* @throws ResourceNotFoundException if template not found
* from any available source.
* @throws ParseErrorException
*/
ContentResource getContent(String name, String encoding)
throws ResourceNotFoundException, ParseErrorException;
/**
* Determines is a template exists, and returns name of the loader that
* provides it. This is a slightly less hokey way to support
* the Velocity.templateExists() utility method, which was broken
* when per-template encoding was introduced. We can revisit this.
*
* @param resourceName Name of template or content resource
* @return class name of loader than can provide it
*/
String getLoaderNameForResource(String resourceName);
/**
* String property accessor method with default to hide the
* configuration implementation.
*
* @param key property key
* @param defaultValue default value to return if key not
* found in resource manager.
* @return String value of key or default
*/
String getString(String key, String defaultValue);
/**
* Returns the appropriate VelocimacroProxy object if strVMname
* is a valid current Velocimacro.
*
* @param vmName Name of velocimacro requested
* @param renderingTemplate Template we are currently rendering. This
* information is needed when VM_PERM_ALLOW_INLINE_REPLACE_GLOBAL setting is true
* and template contains a macro with the same name as the global macro library.
* @param template current template
*
* @return VelocimacroProxy
*/
Directive getVelocimacro(String vmName, Template renderingTemplate, Template template);
/**
* Adds a new Velocimacro. Usually called by Macro only while parsing.
*
* @param name Name of velocimacro
* @param macro root AST node of the parsed macro
* @param macroArgs Array of macro arguments, containing the
* #macro() arguments and default values. the 0th is the name.
* @param definingTemplate template containing macro definition
*
* @return boolean True if added, false if rejected for some
* reason (either parameters or permission settings)
*/
boolean addVelocimacro(String name,
Node macro,
List macroArgs,
Template definingTemplate);
/**
* Checks to see if a VM exists
*
* @param vmName Name of velocimacro
* @param template Template "namespace"
* @return boolean True if VM by that name exists, false if not
*/
boolean isVelocimacro(String vmName, Template template);
/**
* String property accessor method to hide the configuration implementation
* @param key property key
* @return value of key or null
*/
String getString(String key);
/**
* Int property accessor method to hide the configuration implementation.
*
* @param key property key
* @return int value
*/
int getInt(String key);
/**
* Int property accessor method to hide the configuration implementation.
*
* @param key property key
* @param defaultValue default value
* @return int value
*/
int getInt(String key, int defaultValue);
/**
* Boolean property accessor method to hide the configuration implementation.
*
* @param key property key
* @param def default default value if property not found
* @return boolean value of key or default value
*/
boolean getBoolean(String key, boolean def);
/**
* Return the velocity runtime configuration object.
*
* @return ExtProperties configuration object which houses
* the velocity runtime properties.
*/
ExtProperties getConfiguration();
/**
* Return the specified application attribute.
*
* @param key The name of the attribute to retrieve.
* @return The value of the attribute.
*/
Object getApplicationAttribute(Object key);
/**
* Set the specified application attribute.
*
* @param key The name of the attribute to set.
* @param value The attribute value to set.
* @return the displaced attribute value
*/
Object setApplicationAttribute(Object key, Object value);
/**
* Returns the configured class introspection/reflection
* implementation.
* @return The current Uberspect object.
*/
Uberspect getUberspect();
/**
* Returns the configured logger.
* @return A Logger object.
*/
Logger getLog();
/**
* Get a logger for the specified child namespace.
* If a logger was configured using the runtime.log.instance configuration property, returns this instance.
* Otherwise, uses SLF4J LoggerFactory on baseNamespace + childNamespace.
* @param childNamespace
* @return child name space logger
*/
Logger getLog(String childNamespace);
/**
* Get the LogContext object used to tack locations in templates.
* @return LogContext object
* @since 2.2
*/
LogContext getLogContext();
/**
* Returns the event handlers for the application.
* @return The event handlers for the application.
*/
EventCartridge getApplicationEventCartridge();
/**
* Returns true if the RuntimeInstance has been successfully initialized.
* @return True if the RuntimeInstance has been successfully initialized.
*/
boolean isInitialized();
/**
* Create a new parser instance.
* @return A new parser instance.
*/
Parser createNewParser();
/**
* Retrieve a previously instantiated directive.
* @param name name of the directive
* @return the directive with that name, if any
* @since 1.6
*/
Directive getDirective(String name);
/**
* Check whether the engine uses string interning
* @return true if string interning is active
*/
boolean useStringInterning();
/**
* get space gobbling mode
* @return space gobbling mode
*/
SpaceGobbling getSpaceGobbling();
/**
* Get whether hyphens are allowed in identifiers
* @return configured boolean flag
* @since 2.1
*/
boolean isHyphenAllowedInIdentifiers();
/**
* Get whether to provide a scope control object for this scope
* @param scopeName
* @return scope control enabled
* @since 2.1
*/
boolean isScopeControlEnabled(String scopeName);
/**
* Get the replacement characters configured for this runtime service's parser
* @return configured replacement characters
* @since 2.2
*/
ParserConfiguration getParserConfiguration();
}