org.apache.velocity.runtime.RuntimeServices Maven / Gradle / Ivy
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 java.io.IOException;
import java.io.Reader;
import java.io.Writer;
import java.util.Properties;
import org.apache.commons.collections.ExtendedProperties;
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.directive.Directive;
import org.apache.velocity.runtime.log.Log;
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.introspection.Introspector;
import org.apache.velocity.util.introspection.Uberspect;
/**
* 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: RuntimeServices.java 685724 2008-08-13 23:12:12Z nbubna $
*/
public interface RuntimeServices extends RuntimeLogger
{
/**
* 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
*
* @throws Exception
*/
public void init() throws Exception;
/**
* Allows an external system to set a property in
* the Velocity Runtime.
*
* @param key property key
* @param value property value
*/
public void setProperty(String key, Object value);
/**
* Allow an external system to set an ExtendedProperties
* object to use. This is useful where the external
* system also uses the ExtendedProperties class and
* the velocity configuration is a subset of
* parent application's configuration. This is
* the case with Turbine.
*
* @param configuration
*/
public void setConfiguration( ExtendedProperties 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
*/
public void addProperty(String key, Object value);
/**
* Clear the values pertaining to a particular
* property.
*
* @param key of property to clear
*/
public 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.
*/
public Object getProperty( String key );
/**
* Initialize the Velocity Runtime with a Properties
* object.
*
* @param p
* @throws Exception
*/
public void init(Properties p) throws Exception;
/**
* Initialize the Velocity Runtime with the name of
* ExtendedProperties object.
*
* @param configurationFile
* @throws Exception
*/
public void init(String configurationFile) throws Exception;
/**
* Wraps the String in a StringReader and passes it off to
* {@link #parse(Reader,String)}.
* @since 1.6
*/
public SimpleNode parse(String string, String templateName)
throws ParseException;
/**
* 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 templateName name of the template being parsed
* @return The AST representing the template.
* @throws ParseException
*/
public SimpleNode parse( Reader reader, String templateName )
throws ParseException;
/**
* Parse the input and return the root of the AST node structure.
*
* @param reader inputstream retrieved by a resource loader
* @param templateName name of the template being parsed
* @param dumpNamespace flag to dump the Velocimacro namespace for this template
* @return The AST representing the template.
* @throws ParseException
*/
public SimpleNode parse( Reader reader, String templateName, boolean dumpNamespace )
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.
* @throws IOException While rendering to the writer, an I/O problem occured.
* @since Velocity 1.6
*/
public boolean evaluate(Context context, Writer out,
String logTag, String instring) throws IOException;
/**
* 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.
* @throws IOException While reading from the reader or rendering to the writer,
* an I/O problem occured.
* @since Velocity 1.6
*/
public boolean evaluate(Context context, Writer writer,
String logTag, Reader reader) throws IOException;
/**
* 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.
* @throws IOException While rendering to the writer, an I/O problem occured.
* @since 1.6
*/
public boolean invokeVelocimacro(final String vmName, String logTag,
String[] params, final Context context,
final Writer writer) throws IOException;
/**
* 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 "ISO-8859-1"
*
* @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.
* @throws Exception if an error occurs in template initialization
*/
public Template getTemplate(String name)
throws ResourceNotFoundException, ParseErrorException, Exception;
/**
* 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.
* @throws Exception if an error occurs in template initialization
*/
public Template getTemplate(String name, String encoding)
throws ResourceNotFoundException, ParseErrorException, Exception;
/**
* 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
* @throws Exception
*/
public ContentResource getContent(String name)
throws ResourceNotFoundException, ParseErrorException, Exception;
/**
* 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
* @throws Exception
*/
public ContentResource getContent( String name, String encoding )
throws ResourceNotFoundException, ParseErrorException, Exception;
/**
* 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
*/
public 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
*/
public 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 templateName Name of the namespace.
* @return VelocimacroProxy
*/
public Directive getVelocimacro( String vmName, String templateName );
/**
* Returns the appropriate VelocimacroProxy object if strVMname
* is a valid current Velocimacro.
*
* @param vmName Name of velocimacro requested
* @param templateName Name of the namespace.
* @param renderingTemplate Name of the 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.
*
* @since Velocity 1.6
*
* @return VelocimacroProxy
*/
public Directive getVelocimacro( String vmName, String templateName, String renderingTemplate );
/**
* Adds a new Velocimacro. Usually called by Macro only while parsing.
*
* @param name Name of velocimacro
* @param macro String form of macro body
* @param argArray Array of strings, containing the
* #macro() arguments. the 0th is the name.
* @param sourceTemplate
*
* @deprecated Use addVelocimacro(String, Node, String[], String) instead
*
* @return boolean True if added, false if rejected for some
* reason (either parameters or permission settings)
*/
public boolean addVelocimacro( String name,
String macro,
String argArray[],
String sourceTemplate );
/**
* 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 argArray Array of strings, containing the
* #macro() arguments. the 0th is the name.
* @param sourceTemplate
*
* @since Velocity 1.6
*
* @return boolean True if added, false if rejected for some
* reason (either parameters or permission settings)
*/
public boolean addVelocimacro( String name,
Node macro,
String argArray[],
String sourceTemplate );
/**
* Checks to see if a VM exists
*
* @param vmName Name of velocimacro
* @param templateName
* @return boolean True if VM by that name exists, false if not
*/
public boolean isVelocimacro( String vmName, String templateName );
/**
* tells the vmFactory to dump the specified namespace. This is to support
* clearing the VM list when in inline-VM-local-scope mode
* @param namespace
* @return True if the Namespace was dumped.
*/
public boolean dumpVMNamespace( String namespace );
/**
* String property accessor method to hide the configuration implementation
* @param key property key
* @return value of key or null
*/
public String getString(String key);
/**
* Int property accessor method to hide the configuration implementation.
*
* @param key property key
* @return int value
*/
public int getInt( String key );
/**
* Int property accessor method to hide the configuration implementation.
*
* @param key property key
* @param defaultValue default value
* @return int value
*/
public 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
*/
public boolean getBoolean( String key, boolean def );
/**
* Return the velocity runtime configuration object.
*
* @return ExtendedProperties configuration object which houses
* the velocity runtime properties.
*/
public ExtendedProperties getConfiguration();
/**
* Return the specified application attribute.
*
* @param key The name of the attribute to retrieve.
* @return The value of the attribute.
*/
public 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
*/
public Object setApplicationAttribute( Object key, Object value );
/**
* Returns the configured class introspection/reflection
* implementation.
* @return The current Uberspect object.
*/
public Uberspect getUberspect();
/**
* Returns a convenient Log instance that wraps the current LogChute.
* @return A log object.
*/
public Log getLog();
/**
* Returns the event handlers for the application.
* @return The event handlers for the application.
*/
public EventCartridge getApplicationEventCartridge();
/**
* Returns the configured method introspection/reflection
* implementation.
* @return The configured method introspection/reflection
* implementation.
*/
public Introspector getIntrospector();
/**
* Returns true if the RuntimeInstance has been successfully initialized.
* @return True if the RuntimeInstance has been successfully initialized.
*/
public boolean isInitialized();
/**
* Create a new parser instance.
* @return A new parser instance.
*/
public Parser createNewParser();
/**
* Retrieve a previously instantiated directive.
* @param name name of the directive
* @return the directive with that name, if any
* @since 1.6
*/
public Directive getDirective(String name);
}
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