Package org.apache.velocity.runtime

Class RuntimeInstance

  • All Implemented Interfaces:
    RuntimeConstants, RuntimeLogger, RuntimeServices
    public class RuntimeInstance
extends java.lang.Object
implements RuntimeConstants, RuntimeServices
    This is the Runtime system for Velocity. It is the single access point for all functionality in Velocity. It adheres to the mediator pattern and is the only structure that developers need to be familiar with in order to get Velocity to perform. The Runtime will also cooperate with external systems like Turbine. Runtime properties can set and then the Runtime is initialized. Turbine, for example, knows where the templates are to be loaded from, and where the Velocity log file should be placed. So in the case of Velocity cooperating with Turbine the code might look something like the following: 
     ri.setProperty(Runtime.FILE_RESOURCE_LOADER_PATH, templatePath);
 ri.setProperty(Runtime.RUNTIME_LOG, pathToVelocityLog);
 ri.init();
 
     -----------------------------------------------------------------------
 N O T E S  O N  R U N T I M E  I N I T I A L I Z A T I O N
 -----------------------------------------------------------------------
 init()

 If init() is called by itself the RuntimeInstance will initialize
 with a set of default values.
 -----------------------------------------------------------------------
 init(String/Properties)

 In this case the default velocity properties are layed down
 first to provide a solid base, then any properties provided
 in the given properties object will override the corresponding
 default property.
 -----------------------------------------------------------------------
    Version:
    $Id: RuntimeInstance.java 898050 2010-01-11 20:15:31Z nbubna $
    Author:
    Jason van Zyl, Jeff Bowden, Geir Magusson Jr.

    • Constructor Detail

      • RuntimeInstance

        public RuntimeInstance()
        Creates a new RuntimeInstance object.

    • Method Detail

      • init

        public void init()
        This is the primary initialization method in the Velocity Runtime. The systems that are setup/initialized here are as follows:
        • Logging System
        • ResourceManager
        • EventHandler
        • Parser Pool
        • Global Cache
        • Static Content Include System
        • Velocimacro System
        Specified by:
        init in interface RuntimeServices

      • isInitialized

        public boolean isInitialized()
        Returns true if the RuntimeInstance has been successfully initialized.
        Specified by:
        isInitialized in interface RuntimeServices
        Returns:
        True if the RuntimeInstance has been successfully initialized.
        Since:
        1.5

      • setProperty

        public void setProperty​(java.lang.String key,
                        java.lang.Object value)
        Allows an external system to set a property in the Velocity Runtime.
        Specified by:
        setProperty in interface RuntimeServices
        Parameters:
        key - property key
        value - property value

      • setProperties

        public void setProperties​(java.lang.String fileName)
        Add all properties contained in the file fileName to the RuntimeInstance properties

      • setProperties

        public void setProperties​(java.util.Properties props)
        Add all the properties in props to the RuntimeInstance properties

      • setConfiguration

        public void setConfiguration​(org.apache.commons.collections.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.
        Specified by:
        setConfiguration in interface RuntimeServices
        Parameters:
        configuration -

      • addProperty

        public void addProperty​(java.lang.String key,
                        java.lang.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"]
        Specified by:
        addProperty in interface RuntimeServices
        Parameters:
        key -
        value -

      • clearProperty

        public void clearProperty​(java.lang.String key)
        Clear the values pertaining to a particular property.
        Specified by:
        clearProperty in interface RuntimeServices
        Parameters:
        key - of property to clear

      • getProperty

        public java.lang.Object getProperty​(java.lang.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.
        Specified by:
        getProperty in interface RuntimeServices
        Parameters:
        key - property to return
        Returns:
        Value of the property or null if it does not exist.

      • init

        public void init​(java.util.Properties p)
        Initialize the Velocity Runtime with a Properties object.
        Specified by:
        init in interface RuntimeServices
        Parameters:
        p - Velocity properties for initialization

      • init

        public void init​(java.lang.String configurationFile)
        Initialize the Velocity Runtime with the name of ExtendedProperties object.
        Specified by:
        init in interface RuntimeServices
        Parameters:
        configurationFile -

      • addDirective

        public void addDirective​(Directive directive)
        Programatically add a directive.
        Parameters:
        directive -

      • getDirective

        public Directive getDirective​(java.lang.String name)
        Retrieve a previously instantiated directive.
        Specified by:
        getDirective in interface RuntimeServices
        Parameters:
        name - name of the directive
        Returns:
        the Directive for that name

      • removeDirective

        public void removeDirective​(java.lang.String name)
        Remove a directive.
        Parameters:
        name - name of the directive.

      • loadDirective

        public void loadDirective​(java.lang.String directiveClass)
        instantiates and loads the directive with some basic checks
        Parameters:
        directiveClass - classname of directive to load

      • createNewParser

        public Parser createNewParser()
        Returns a JavaCC generated Parser.
        Specified by:
        createNewParser in interface RuntimeServices
        Returns:
        Parser javacc generated parser

      • parse

        public SimpleNode parse​(java.lang.String string,
                        java.lang.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.
        Specified by:
        parse in interface RuntimeServices
        Parameters:
        string - String to be parsed
        templateName - name of the template being parsed
        Returns:
        A root node representing the template as an AST tree.
        Throws:
        ParseException - When the string could not be parsed as a template.
        Since:
        1.6

      • parse

        public SimpleNode parse​(java.io.Reader reader,
                        java.lang.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.
        Specified by:
        parse in interface RuntimeServices
        Parameters:
        reader - Reader retrieved by a resource loader
        templateName - name of the template being parsed
        Returns:
        A root node representing the template as an AST tree.
        Throws:
        ParseException - When the template could not be parsed.

      • parse

        public SimpleNode parse​(java.io.Reader reader,
                        java.lang.String templateName,
                        boolean dumpNamespace)
                 throws ParseException
        Parse the input and return the root of the AST node structure.
        Specified by:
        parse in interface RuntimeServices
        Parameters:
        reader - Reader retrieved by a resource loader
        templateName - name of the template being parsed
        dumpNamespace - flag to dump the Velocimacro namespace for this template
        Returns:
        A root node representing the template as an AST tree.
        Throws:
        ParseException - When the template could not be parsed.

      • evaluate

        public boolean evaluate​(Context context,
                        java.io.Writer out,
                        java.lang.String logTag,
                        java.lang.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.
        Specified by:
        evaluate in interface RuntimeServices
        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.
        Since:
        Velocity 1.6

      • evaluate

        public boolean evaluate​(Context context,
                        java.io.Writer writer,
                        java.lang.String logTag,
                        java.io.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.
        Specified by:
        evaluate in interface RuntimeServices
        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

      • render

        public boolean render​(Context context,
                      java.io.Writer writer,
                      java.lang.String logTag,
                      SimpleNode nodeTree)
        Initializes and renders the AST SimpleNode using the context into the output writer.
        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
        nodeTree - SimpleNode which is the root of the AST to be rendered
        Returns:
        true if successful, false otherwise. If false, see Velocity runtime log for errors
        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

        public boolean invokeVelocimacro​(java.lang.String vmName,
                                 java.lang.String logTag,
                                 java.lang.String[] params,
                                 Context context,
                                 java.io.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.
        Specified by:
        invokeVelocimacro in interface RuntimeServices
        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

      • getLoaderNameForResource

        public java.lang.String getLoaderNameForResource​(java.lang.String resourceName)
        Determines if a template exists and returns name of the loader that provides it. This is a slightly less hokey way to support the Velocity.resourceExists() utility method, which was broken when per-template encoding was introduced. We can revisit this.
        Specified by:
        getLoaderNameForResource in interface RuntimeServices
        Parameters:
        resourceName - Name of template or content resource
        Returns:
        class name of loader than can provide it

      • getLog

        public Log getLog()
        Returns a convenient Log instance that wraps the current LogChute. Use this to log error messages. It has the usual methods.
        Specified by:
        getLog in interface RuntimeServices
        Returns:
        A convenience Log instance that wraps the current LogChute.
        Since:
        1.5

      • warn

        public void warn​(java.lang.Object message)
        Deprecated.
        Use getLog() and call warn() on it.
        Specified by:
        warn in interface RuntimeLogger
        Parameters:
        message - The message to log.
        See Also:
        Log.warn(Object)

      • info

        public void info​(java.lang.Object message)
        Deprecated.
        Use getLog() and call info() on it.
        Specified by:
        info in interface RuntimeLogger
        Parameters:
        message - The message to log.
        See Also:
        Log.info(Object)

      • error

        public void error​(java.lang.Object message)
        Deprecated.
        Use getLog() and call error() on it.
        Specified by:
        error in interface RuntimeLogger
        Parameters:
        message - The message to log.
        See Also:
        Log.error(Object)

      • debug

        public void debug​(java.lang.Object message)
        Deprecated.
        Use getLog() and call debug() on it.
        Specified by:
        debug in interface RuntimeLogger
        Parameters:
        message - The message to log.
        See Also:
        Log.debug(Object)

      • getString

        public java.lang.String getString​(java.lang.String key,
                                  java.lang.String defaultValue)
        String property accessor method with default to hide the configuration implementation.
        Specified by:
        getString in interface RuntimeServices
        Parameters:
        key - property key
        defaultValue - default value to return if key not found in resource manager.
        Returns:
        value of key or default

      • getVelocimacro

        public Directive getVelocimacro​(java.lang.String vmName,
                                java.lang.String templateName)
        Returns the appropriate VelocimacroProxy object if vmName is a valid current Velocimacro.
        Specified by:
        getVelocimacro in interface RuntimeServices
        Parameters:
        vmName - Name of velocimacro requested
        templateName - Name of the template that contains the velocimacro.
        Returns:
        The requested VelocimacroProxy.
        Since:
        1.6

      • getVelocimacro

        public Directive getVelocimacro​(java.lang.String vmName,
                                java.lang.String templateName,
                                java.lang.String renderingTemplate)
        Returns the appropriate VelocimacroProxy object if vmName is a valid current Velocimacro.
        Specified by:
        getVelocimacro in interface RuntimeServices
        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

        public boolean addVelocimacro​(java.lang.String name,
                              java.lang.String macro,
                              java.lang.String[] argArray,
                              java.lang.String sourceTemplate)
        Deprecated.
        Use addVelocimacro(String, Node, String[], String) instead
        Adds a new Velocimacro. Usually called by Macro only while parsing.
        Specified by:
        addVelocimacro in interface RuntimeServices
        Parameters:
        name - Name of velocimacro
        macro - String form of macro body
        argArray - Array of strings, containing the #macro() arguments. the 0th is the name.
        sourceTemplate - Name of the template that contains the velocimacro.
        Returns:
        True if added, false if rejected for some reason (either parameters or permission settings)

      • addVelocimacro

        public boolean addVelocimacro​(java.lang.String name,
                              Node macro,
                              java.lang.String[] argArray,
                              java.lang.String sourceTemplate)
        Adds a new Velocimacro. Usually called by Macro only while parsing. Called by org.apache.velocity.runtime.directive.processAndRegister
        Specified by:
        addVelocimacro in interface RuntimeServices
        Parameters:
        name - Name of velocimacro
        macro - root AST node of the parsed macro
        argArray - Array of strings, containing the #macro() arguments. 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

        public boolean isVelocimacro​(java.lang.String vmName,
                             java.lang.String templateName)
        Checks to see if a VM exists
        Specified by:
        isVelocimacro in interface RuntimeServices
        Parameters:
        vmName - Name of the Velocimacro.
        templateName - Template on which to look for the Macro.
        Returns:
        True if VM by that name exists, false if not

      • dumpVMNamespace

        public boolean dumpVMNamespace​(java.lang.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
        Specified by:
        dumpVMNamespace in interface RuntimeServices
        Parameters:
        namespace - Namespace to dump.
        Returns:
        True if namespace was dumped successfully.

      • getString

        public java.lang.String getString​(java.lang.String key)
        String property accessor method to hide the configuration implementation
        Specified by:
        getString in interface RuntimeServices
        Parameters:
        key - property key
        Returns:
        value of key or null

      • getInt

        public int getInt​(java.lang.String key)
        Int property accessor method to hide the configuration implementation.
        Specified by:
        getInt in interface RuntimeServices
        Parameters:
        key - Property key
        Returns:
        value

      • getInt

        public int getInt​(java.lang.String key,
                  int defaultValue)
        Int property accessor method to hide the configuration implementation.
        Specified by:
        getInt in interface RuntimeServices
        Parameters:
        key - property key
        defaultValue - The default value.
        Returns:
        value

      • getBoolean

        public boolean getBoolean​(java.lang.String key,
                          boolean def)
        Boolean property accessor method to hide the configuration implementation.
        Specified by:
        getBoolean in interface RuntimeServices
        Parameters:
        key - property key
        def - The default value if property not found.
        Returns:
        value of key or default value

      • getConfiguration

        public org.apache.commons.collections.ExtendedProperties getConfiguration()
        Return the velocity runtime configuration object.
        Specified by:
        getConfiguration in interface RuntimeServices
        Returns:
        Configuration object which houses the Velocity runtime properties.

      • getApplicationAttribute

        public java.lang.Object getApplicationAttribute​(java.lang.Object key)
        Gets the application attribute for the given key
        Specified by:
        getApplicationAttribute in interface RuntimeServices
        Parameters:
        key -
        Returns:
        The application attribute for the given key.

      • setApplicationAttribute

        public java.lang.Object setApplicationAttribute​(java.lang.Object key,
                                                java.lang.Object o)
        Sets the application attribute for the given key
        Specified by:
        setApplicationAttribute in interface RuntimeServices
        Parameters:
        key -
        o - The new application attribute.
        Returns:
        The old value of this attribute or null if it hasn't been set before.

      • getUberspect

        public Uberspect getUberspect()
        Returns the Uberspect object for this Instance.
        Specified by:
        getUberspect in interface RuntimeServices
        Returns:
        The Uberspect object for this Instance.