org.apache.velocity.runtime
Interface RuntimeServices

All Known Implementing Classes:
RuntimeInstance

public interface RuntimeServices

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.

Version:
$Id: RuntimeServices.java 898052 2010-01-11 20:19:20Z nbubna $
Author:
Geir Magusson Jr.

Method Summary
 void addProperty(String key, Object value)
          Add a property to the configuration.
 boolean addVelocimacro(String name, Node macro, List<Macro.MacroArg> macroArgs, String sourceTemplate)
          Adds a new Velocimacro.
 void clearProperty(String key)
          Clear the values pertaining to a particular property.
 Parser createNewParser()
          Create a new parser instance.
 boolean dumpVMNamespace(String namespace)
          tells the vmFactory to dump the specified namespace.
 boolean evaluate(Context context, Writer writer, String logTag, Reader reader)
          Renders the input reader using the context into the output writer.
 boolean evaluate(Context context, Writer out, String logTag, String instring)
          Renders the input string using the context into the output writer.
 Object getApplicationAttribute(Object key)
          Return the specified application attribute.
 EventCartridge getApplicationEventCartridge()
          Returns the event handlers for the application.
 boolean getBoolean(String key, boolean def)
          Boolean property accessor method to hide the configuration implementation.
 ExtendedProperties getConfiguration()
          Return the velocity runtime configuration object.
 ContentResource getContent(String name)
          Returns a static content resource from the resource manager.
 ContentResource getContent(String name, String encoding)
          Returns a static content resource from the resource manager.
 Directive getDirective(String name)
          Retrieve a previously instantiated directive.
 int getInt(String key)
          Int property accessor method to hide the configuration implementation.
 int getInt(String key, int defaultValue)
          Int property accessor method to hide the configuration implementation.
 Introspector getIntrospector()
          Returns the configured method introspection/reflection implementation.
 String getLoaderNameForResource(String resourceName)
          Determines is a template exists, and returns name of the loader that provides it.
 Log getLog()
          Returns a convenient Log instance that wraps the current LogChute.
 Object getProperty(String key)
          Allows an external caller to get a property.
 String getString(String key)
          String property accessor method to hide the configuration implementation
 String getString(String key, String defaultValue)
          String property accessor method with default to hide the configuration implementation.
 Template getTemplate(String name)
          Returns a Template from the resource manager.
 Template getTemplate(String name, String encoding)
          Returns a Template from the resource manager
 Uberspect getUberspect()
          Returns the configured class introspection/reflection implementation.
 Directive getVelocimacro(String vmName, String templateName)
          Returns the appropriate VelocimacroProxy object if strVMname is a valid current Velocimacro.
 Directive getVelocimacro(String vmName, String templateName, String renderingTemplate)
          Returns the appropriate VelocimacroProxy object if strVMname is a valid current Velocimacro.
 void init()
          This is the primary initialization method in the Velocity Runtime.
 void init(Properties p)
          Initialize the Velocity Runtime with a Properties object.
 void init(String configurationFile)
          Initialize the Velocity Runtime with the name of ExtendedProperties object.
 boolean invokeVelocimacro(String vmName, String logTag, String[] params, Context context, Writer writer)
          Invokes a currently registered Velocimacro with the params provided and places the rendered stream into the writer.
 boolean isInitialized()
          Returns true if the RuntimeInstance has been successfully initialized.
 boolean isVelocimacro(String vmName, String templateName)
          Checks to see if a VM exists
 SimpleNode parse(Reader reader, String templateName)
          Parse the input and return the root of AST node structure.
 SimpleNode parse(Reader reader, String templateName, boolean dumpNamespace)
          Parse the input and return the root of the AST node structure.
 SimpleNode parse(String string, String templateName)
          Wraps the String in a StringReader and passes it off to parse(Reader,String).
 Object setApplicationAttribute(Object key, Object value)
          Set the specified application attribute.
 void setConfiguration(ExtendedProperties configuration)
          Allow an external system to set an ExtendedProperties object to use.
 void setProperty(String key, Object value)
          Allows an external system to set a property in the Velocity Runtime.
 

Method Detail

init

void init()
This is the primary initialization method in the Velocity Runtime. The systems that are setup/initialized here are as follows:


setProperty

void setProperty(String key,
                 Object value)
Allows an external system to set a property in the Velocity Runtime.

Parameters:
key - property key
value - property value

setConfiguration

void setConfiguration(ExtendedProperties configuration)
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.

Parameters:
configuration -

addProperty

void addProperty(String key,
                 Object value)
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"]

Parameters:
key -
value -

clearProperty

void clearProperty(String key)
Clear the values pertaining to a particular property.

Parameters:
key - of property to clear

getProperty

Object getProperty(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.

Parameters:
key - property to return
Returns:
The value.

init

void init(Properties p)
Initialize the Velocity Runtime with a Properties object.

Parameters:
p -

init

void init(String configurationFile)
Initialize the Velocity Runtime with the name of ExtendedProperties object.

Parameters:
configurationFile -

parse

SimpleNode parse(String string,
                 String templateName)
                 throws ParseException
Wraps the String in a StringReader and passes it off to parse(Reader,String).

Throws:
ParseException
Since:
1.6

parse

SimpleNode parse(Reader reader,
                 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.

Parameters:
reader - inputstream retrieved by a resource loader
templateName - name of the template being parsed
Returns:
The AST representing the template.
Throws:
ParseException

parse

SimpleNode parse(Reader reader,
                 String templateName,
                 boolean dumpNamespace)
                 throws ParseException
Parse the input and return the root of the AST node structure.

Parameters:
reader - inputstream retrieved by a resource loader
templateName - name of the template being parsed
dumpNamespace - flag to dump the Velocimacro namespace for this template
Returns:
The AST representing the template.
Throws:
ParseException

evaluate

boolean evaluate(Context context,
                 Writer out,
                 String logTag,
                 String instring)
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.

Parameters:
context - context to use in rendering input string
out - Writer in which to render the output
logTag - string to be used as the template name for log messages in case of error
instring - input string containing the VTL to be rendered
Returns:
true if successful, false otherwise. If false, see Velocity runtime log
Throws:
ParseErrorException - The template could not be parsed.
MethodInvocationException - A method on a context object could not be invoked.
ResourceNotFoundException - A referenced resource could not be loaded.
IOException - While rendering to the writer, an I/O problem occured.
Since:
Velocity 1.6

evaluate

boolean evaluate(Context context,
                 Writer writer,
                 String logTag,
                 Reader reader)
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.

Parameters:
context - context to use in rendering input string
writer - Writer in which to render the output
logTag - string to be used as the template name for log messages in case of error
reader - Reader containing the VTL to be rendered
Returns:
true if successful, false otherwise. If false, see Velocity runtime log
Throws:
ParseErrorException - The template could not be parsed.
MethodInvocationException - A method on a context object could not be invoked.
ResourceNotFoundException - A referenced resource could not be loaded.
Since:
Velocity 1.6

invokeVelocimacro

boolean invokeVelocimacro(String vmName,
                          String logTag,
                          String[] params,
                          Context context,
                          Writer writer)
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.

Parameters:
vmName - name of Velocimacro to call
logTag - string to be used for template name in case of error. if null, the vmName will be used
params - keys for args used to invoke Velocimacro, in java format rather than VTL (eg "foo" or "bar" rather than "$foo" or "$bar")
context - Context object containing data/objects used for rendering.
writer - Writer for output stream
Returns:
true if Velocimacro exists and successfully invoked, false otherwise.
Since:
1.6

getTemplate

Template getTemplate(String name)
                     throws ResourceNotFoundException,
                            ParseErrorException
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"

Parameters:
name - The file name of the desired template.
Returns:
The template.
Throws:
ResourceNotFoundException - if template not found from any available source.
ParseErrorException - if template cannot be parsed due to syntax (or other) error.

getTemplate

Template getTemplate(String name,
                     String encoding)
                     throws ResourceNotFoundException,
                            ParseErrorException
Returns a Template from the resource manager

Parameters:
name - The name of the desired template.
encoding - Character encoding of the template
Returns:
The template.
Throws:
ResourceNotFoundException - if template not found from any available source.
ParseErrorException - if template cannot be parsed due to syntax (or other) error.

getContent

ContentResource getContent(String name)
                           throws ResourceNotFoundException,
                                  ParseErrorException
Returns a static content resource from the resource manager. Uses the current value if INPUT_ENCODING as the character encoding.

Parameters:
name - Name of content resource to get
Returns:
parsed ContentResource object ready for use
Throws:
ResourceNotFoundException - if template not found from any available source.
ParseErrorException

getContent

ContentResource getContent(String name,
                           String encoding)
                           throws ResourceNotFoundException,
                                  ParseErrorException
Returns a static content resource from the resource manager.

Parameters:
name - Name of content resource to get
encoding - Character encoding to use
Returns:
parsed ContentResource object ready for use
Throws:
ResourceNotFoundException - if template not found from any available source.
ParseErrorException

getLoaderNameForResource

String getLoaderNameForResource(String resourceName)
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.

Parameters:
resourceName - Name of template or content resource
Returns:
class name of loader than can provide it

getString

String getString(String key,
                 String defaultValue)
String property accessor method with default to hide the configuration implementation.

Parameters:
key - property key
defaultValue - default value to return if key not found in resource manager.
Returns:
String value of key or default

getVelocimacro

Directive getVelocimacro(String vmName,
                         String templateName)
Returns the appropriate VelocimacroProxy object if strVMname is a valid current Velocimacro.

Parameters:
vmName - Name of velocimacro requested
templateName - Name of the namespace.
Returns:
VelocimacroProxy

getVelocimacro

Directive getVelocimacro(String vmName,
                         String templateName,
                         String renderingTemplate)
Returns the appropriate VelocimacroProxy object if strVMname is a valid current Velocimacro.

Parameters:
vmName - Name of velocimacro requested
templateName - Name of the namespace.
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.
Returns:
VelocimacroProxy
Since:
Velocity 1.6

addVelocimacro

boolean addVelocimacro(String name,
                       Node macro,
                       List<Macro.MacroArg> macroArgs,
                       String sourceTemplate)
Adds a new Velocimacro. Usually called by Macro only while parsing.

Parameters:
name - Name of velocimacro
macro - root AST node of the parsed macro
macroArgs - Array of macro arguments, containing the #macro() arguments and default values. the 0th is the name.
sourceTemplate -
Returns:
boolean True if added, false if rejected for some reason (either parameters or permission settings)
Since:
Velocity 1.6

isVelocimacro

boolean isVelocimacro(String vmName,
                      String templateName)
Checks to see if a VM exists

Parameters:
vmName - Name of velocimacro
templateName -
Returns:
boolean True if VM by that name exists, false if not

dumpVMNamespace

boolean dumpVMNamespace(String namespace)
tells the vmFactory to dump the specified namespace. This is to support clearing the VM list when in inline-VM-local-scope mode

Parameters:
namespace -
Returns:
True if the Namespace was dumped.

getString

String getString(String key)
String property accessor method to hide the configuration implementation

Parameters:
key - property key
Returns:
value of key or null

getInt

int getInt(String key)
Int property accessor method to hide the configuration implementation.

Parameters:
key - property key
Returns:
int value

getInt

int getInt(String key,
           int defaultValue)
Int property accessor method to hide the configuration implementation.

Parameters:
key - property key
defaultValue - default value
Returns:
int value

getBoolean

boolean getBoolean(String key,
                   boolean def)
Boolean property accessor method to hide the configuration implementation.

Parameters:
key - property key
def - default default value if property not found
Returns:
boolean value of key or default value

getConfiguration

ExtendedProperties getConfiguration()
Return the velocity runtime configuration object.

Returns:
ExtendedProperties configuration object which houses the velocity runtime properties.

getApplicationAttribute

Object getApplicationAttribute(Object key)
Return the specified application attribute.

Parameters:
key - The name of the attribute to retrieve.
Returns:
The value of the attribute.

setApplicationAttribute

Object setApplicationAttribute(Object key,
                               Object value)
Set the specified application attribute.

Parameters:
key - The name of the attribute to set.
value - The attribute value to set.
Returns:
the displaced attribute value

getUberspect

Uberspect getUberspect()
Returns the configured class introspection/reflection implementation.

Returns:
The current Uberspect object.

getLog

Log getLog()
Returns a convenient Log instance that wraps the current LogChute.

Returns:
A log object.

getApplicationEventCartridge

EventCartridge getApplicationEventCartridge()
Returns the event handlers for the application.

Returns:
The event handlers for the application.

getIntrospector

Introspector getIntrospector()
Returns the configured method introspection/reflection implementation.

Returns:
The configured method introspection/reflection implementation.

isInitialized

boolean isInitialized()
Returns true if the RuntimeInstance has been successfully initialized.

Returns:
True if the RuntimeInstance has been successfully initialized.

createNewParser

Parser createNewParser()
Create a new parser instance.

Returns:
A new parser instance.

getDirective

Directive getDirective(String name)
Retrieve a previously instantiated directive.

Parameters:
name - name of the directive
Returns:
the directive with that name, if any
Since:
1.6


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