vodserver.parambuilder

Class ScriptedParamBuilder

java.lang.Object

vodserver.util.BaseBeanNameAware

vodserver.parambuilder.AbstractParamBuilder

vodserver.parambuilder.ScriptedParamBuilder

All Implemented Interfaces:

Comparable<ParamBuilder>, org.springframework.beans.factory.Aware, org.springframework.beans.factory.BeanNameAware, org.springframework.beans.factory.InitializingBean, org.springframework.core.Ordered, ParamBuilder

public class ScriptedParamBuilder
extends AbstractParamBuilder

This ParamBuilder implementation can execute arbitrary scripts to build one or more parameters. This allows for very flexible and powerful ParamBuilder instances. All functionality provided by other ParamBuilders (and more) can also be accomplished with a ScriptedParamBuilder.

This ParamBuilder is based on Java's ScriptEngine API, allowing additional script engines to be added by adding a script engine jar file on the VODServer class path. Java comes bundled with the Rhino JavaScript engine, meaning JavaScript is supported out of the box. Other script engines should work as well, but have not been tested.

The script engine to use is configured using the scriptEngineName property, the default is js (JavaScript). The actual script to execute is configured using the script property. If the script engine supports compilation, the script is pre-compiled upon initialization of this ParamBuilder.

Apart from the standard script engine/Java integration, the following objects are available within the script context:

• params
  The ParamBuilder parameter map. To add parameters, use params.put(name, value). To retrieve existing parameters, use params.get(name).
• util
  Provides access to various VODServer utility methods. This includes utility methods for logging, retrieving HTTP content, and evaluating regular expressions. Please see ScriptedParamBuilder.ScriptUtil for a complete overview of available methods.
• request
  The original HttpServletRequest used to invoke the service. For a complete overview of methods, please refer to the Java HttpServletRequest documentation. In order to access a specific request parameter, you can use request.getRequestParameter(name).

Author:

Ruud Senden

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ScriptedParamBuilder.ScriptUtil An instance of this utility class is available in the script context under the name 'util'.

Field Summary

Fields inherited from interface org.springframework.core.Ordered

HIGHEST_PRECEDENCE, LOWEST_PRECEDENCE

Constructor Summary

Constructors

Constructor and Description
ScriptedParamBuilder()

Method Summary

Methods

Modifier and Type	Method and Description
void	buildParams(Map<String,String> params, javax.servlet.http.HttpServletRequest request) Build the parameters; this will simply invoke the configured script to build the parameters.
protected void	extraAfterPropertiesSet() Upon initialization, if the configured script engine supports compilation, we will pre-compile the configured script.
protected Bindings	getBindings(Map<String,String> params, javax.servlet.http.HttpServletRequest request) Get the bindings used for executing the script.
String	getScript() Get the configured script.
void	setScript(String script) Set the script to execute.
void	setScriptEngineName(String scriptEngineName) Set the script engine name.
String	toString() Provide a useful string representation of this ParamBuilder, showing the script engine used, whether the script was precompiled, and the script contents.

Methods inherited from class vodserver.parambuilder.AbstractParamBuilder

afterPropertiesSet, compareTo, getOrder, setOrder

Methods inherited from class vodserver.util.BaseBeanNameAware

getBeanName, setBeanName

Methods inherited from class java.lang.Object

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

Constructor Detail

ScriptedParamBuilder

public ScriptedParamBuilder()

Method Detail

buildParams

public void buildParams(Map<String,String> params,
               javax.servlet.http.HttpServletRequest request)

Build the parameters; this will simply invoke the configured script to build the parameters.

Parameters:

params - The parameters map to which parameters can be added or existing parameters can be retrieved.

request - The original request, useful to retrieve request parameters for example.

getBindings

protected Bindings getBindings(Map<String,String> params,
                   javax.servlet.http.HttpServletRequest request)

Get the bindings used for executing the script. This makes a predefined set of objects available within the script context.

Parameters:

params -

request -

Returns:

extraAfterPropertiesSet

protected void extraAfterPropertiesSet()

Upon initialization, if the configured script engine supports compilation, we will pre-compile the configured script.

Overrides:

extraAfterPropertiesSet in class AbstractParamBuilder

setScriptEngineName

public void setScriptEngineName(String scriptEngineName)

Set the script engine name. Please refer to the documentation of your script engine for the correct name to use. The default is js, which maps to Java's built-in Rhino JavaScript engine.

Parameters:

scriptEngineName -

getScript

public String getScript()

Get the configured script.

Returns:

setScript

public void setScript(String script)

Set the script to execute.

Parameters:

script -

toString

public String toString()

Provide a useful string representation of this ParamBuilder, showing the script engine used, whether the script was precompiled, and the script contents.

Overrides:

toString in class Object