com.epimorphics.lda.renderers.velocity

Class VelocityRendering

java.lang.Object

com.epimorphics.lda.renderers.velocity.VelocityRendering

All Implemented Interfaces:

Renderer.BytesOut

public class VelocityRendering
extends Object
implements Renderer.BytesOut

A VelocityRendering captures the state required to render a particular request into some output format using Velocity macros. There is one VelocityRendering object per incoming request.

Author:

Ian Dickinson, Epimorphics (mailto:ian@epimorphics.com)

Field Summary

Fields

Modifier and Type	Field and Description
static String	DEFAULT_VELOCITY_ROOT_PATH The default place we look for Velocity files
static String	VELOCITY_FILE_RESOURCE_LOADER_PATH Velocity property for configuring loader path
static String	VELOCITY_PATH_CONFIG_PARAM The configuration parameter which sets an alternative location for Velocity templates etc
static String	VELOCITY_PATH_ENV_VAR Name of environment var to check for a velocity root directory
static String	VELOCITY_PROPERTIES_FILE Name of the properties file

Constructor Summary

Constructors

Constructor and Description
VelocityRendering(Bindings b, APIResultSet rs, VelocityRenderer vr) Construct a Velocity rendering closure

Method Summary

Methods

Modifier and Type	Method and Description
protected void	addBindingsToContext(org.apache.velocity.VelocityContext vc, Bindings binds) Add the Elda bindings as context variables
protected void	addContextSelfReference(org.apache.velocity.VelocityContext vc) Add the Velocity Contex itself, as a debugging aide
protected void	addEventHandlers(org.apache.velocity.VelocityContext vc) Attach the event handlers we want
protected void	addStandardVariables(org.apache.velocity.VelocityContext vc, Page page, DisplayHierarchy dh) Add the standard variables to the context
protected void	addTools(org.apache.velocity.VelocityContext vc) Add generic tools to the Velocity context
protected void	coerceAllMetadata() Irrespective of what is stated in the request URL, we ensure that we see all of the available metadata for this endpoint
protected org.apache.velocity.VelocityContext	createVelocityContext(Bindings binds)
protected org.apache.velocity.app.VelocityEngine	createVelocityEngine() Create a Velocity engine instance, and initialise it with properties loaded from the velocity.properties file.
protected String	defaultVelocityRoot()
protected List<String>	expandVelocityPath(Bindings b)
protected Properties	getProperties(List<String> velocityPath)
protected DisplayHierarchy	initialiseHierarchy(Page page) Initialise the display hierarchy, which unrolls the RDF graph into a displayable tree
protected Page	initialisePage()
protected void	loadPropertiesFile(List<String> velocityPath, Properties p) Load the velocity.properties file from the Velocity root, if it exists.
protected void	render(OutputStream os) Render the top-level template, given the result set and other state stored in this rendering closure.
protected void	setDynamicProperties(List<String> velocityPath, Properties p) Set additional properties that are calculated based on current state
void	writeAll(Times times, OutputStream os) Write the rendered output to the output stream, and side-effect the given Times object to record duration and output counts.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

DEFAULT_VELOCITY_ROOT_PATH

public static final String DEFAULT_VELOCITY_ROOT_PATH

The default place we look for Velocity files

See Also:

Constant Field Values

VELOCITY_PATH_CONFIG_PARAM

public static final String VELOCITY_PATH_CONFIG_PARAM

The configuration parameter which sets an alternative location for Velocity templates etc

See Also:

Constant Field Values

VELOCITY_PATH_ENV_VAR

public static final String VELOCITY_PATH_ENV_VAR

Name of environment var to check for a velocity root directory

See Also:

Constant Field Values

VELOCITY_PROPERTIES_FILE

public static final String VELOCITY_PROPERTIES_FILE

Name of the properties file

See Also:

Constant Field Values

VELOCITY_FILE_RESOURCE_LOADER_PATH

public static final String VELOCITY_FILE_RESOURCE_LOADER_PATH

Velocity property for configuring loader path

See Also:

Constant Field Values

Constructor Detail

VelocityRendering

public VelocityRendering(Bindings b,
                 APIResultSet rs,
                 VelocityRenderer vr)

Construct a Velocity rendering closure

Parameters:

b - Current bindings

rs - Current result set

vr - Reference to the Velocity renderer object, which is also a container for some of the configuration information

Method Detail

writeAll

public void writeAll(Times times,
            OutputStream os)

Write the rendered output to the output stream, and side-effect the given Times object to record duration and output counts.

Specified by:

writeAll in interface Renderer.BytesOut

Parameters:

times - Record used to capture time and size information on output

os - The output stream to write to

coerceAllMetadata

protected void coerceAllMetadata()

Irrespective of what is stated in the request URL, we ensure that we see all of the available metadata for this endpoint

render

protected void render(OutputStream os)

Render the top-level template, given the result set and other state stored in this rendering closure.

Parameters:

os - The output stream to write to

createVelocityEngine

protected org.apache.velocity.app.VelocityEngine createVelocityEngine()

Create a Velocity engine instance, and initialise it with properties loaded from the velocity.properties file.

Returns:

A new Velocity engine

expandVelocityPath

protected List<String> expandVelocityPath(Bindings b)

Returns:

An array of expanded file paths or other URLs where we will search for Velocity assets

defaultVelocityRoot

protected String defaultVelocityRoot()

Returns:

The default Velocity root directory, which may set by an environment variable

getProperties

protected Properties getProperties(List<String> velocityPath)

Returns:

A properties object containing the configuration properties for this velocity instance

setDynamicProperties

protected void setDynamicProperties(List<String> velocityPath,
                        Properties p)

Set additional properties that are calculated based on current state

Parameters:

velocityPath - The Velocity path as given

p - The current Properties object

loadPropertiesFile

protected void loadPropertiesFile(List<String> velocityPath,
                      Properties p)

Load the velocity.properties file from the Velocity root, if it exists.

Parameters:

velocityPath - One or more Velocity root directories to look in

p - Properties to instantiate

createVelocityContext

protected org.apache.velocity.VelocityContext createVelocityContext(Bindings binds)

Returns:

A new velocity context containing bindings that we will use to render the results

addStandardVariables

protected void addStandardVariables(org.apache.velocity.VelocityContext vc,
                        Page page,
                        DisplayHierarchy dh)

Add the standard variables to the context

addBindingsToContext

protected void addBindingsToContext(org.apache.velocity.VelocityContext vc,
                        Bindings binds)

Add the Elda bindings as context variables

addEventHandlers

protected void addEventHandlers(org.apache.velocity.VelocityContext vc)

Attach the event handlers we want

addContextSelfReference

protected void addContextSelfReference(org.apache.velocity.VelocityContext vc)

Add the Velocity Contex itself, as a debugging aide

addTools

protected void addTools(org.apache.velocity.VelocityContext vc)

Add generic tools to the Velocity context

initialiseHierarchy

protected DisplayHierarchy initialiseHierarchy(Page page)

Initialise the display hierarchy, which unrolls the RDF graph into a displayable tree

Parameters:

page - The current page object

Returns:

The display hierarchy

initialisePage

protected Page initialisePage()

Returns:

A new Page object providing access to the page of results