org.apache.commons.digester3.plugins
Class PluginContext

java.lang.Object
  org.apache.commons.digester3.plugins.PluginContext

public class PluginContext
extends Object

Provides data and services which should exist only once per digester.

This class holds a number of useful items which should be shared by all plugin objects. Such data cannot be stored on the PluginRules or PluginManager classes, as there can be multiple instances of these at various times during a parse.

The name "Context" refers to the similarity between this class and a ServletContext class in a servlet engine. A ServletContext object provides access to the container's services such as obtaining global configuration parameters for the container, or getting access to logging services. For plugins, a Digester instance can be regarded as "the container".

Since:

1.6

Constructor Summary

PluginContext()

Method Summary

String	getPluginClassAttr() Get the namespace for the xml attribute which indicates to a PluginCreateRule which class is to be plugged in.
String	getPluginClassAttrNs() Get the namespace for the xml attribute which indicates to a PluginCreateRule which class is to be plugged in.
String	getPluginIdAttr() Get the namespace for the xml attribute which indicates to a PluginCreateRule which previous plugin declaration should be used.
String	getPluginIdAttrNs() Get the namespace for the xml attribute which indicates to a PluginCreateRule which previous plugin declaration should be used.
List<RuleFinder>	getRuleFinders() Return the list of RuleFinder objects.
void	setPluginClassAttribute(String namespaceUri, String attrName) Sets the xml attribute which the input xml uses to indicate to a PluginCreateRule which class should be instantiated.
void	setPluginIdAttribute(String namespaceUri, String attrName) Sets the xml attribute which the input xml uses to indicate to a PluginCreateRule which plugin declaration is being referenced.
void	setRuleFinders(List<RuleFinder> ruleFinders) Set the list of RuleFinder objects.

Methods inherited from class java.lang.Object

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

Constructor Detail

PluginContext

public PluginContext()

Method Detail

getRuleFinders

public List<RuleFinder> getRuleFinders()

Return the list of RuleFinder objects. Under normal circumstances this method creates a default list of these objects when first called (ie "on-demand" or "lazy initialization"). However if setRuleFinders has been called first, then the list specified there is returned.

It is explicitly permitted for the caller to modify this list by inserting or removing RuleFinder objects.

Returns:

the list of RuleFinder objects

setRuleFinders

public void setRuleFinders(List<RuleFinder> ruleFinders)

Set the list of RuleFinder objects. This may be useful if working in a non-english language, allowing the application developer to replace the standard list with a list of objects which look for xml attributes in the local language.

If the intent is just to add an additional rule-finding algorithm, then it may be better to call #getRuleFinders, and insert a new object into the start of the list.

Parameters:

ruleFinders - the list of RuleFinder objects

setPluginClassAttribute

public void setPluginClassAttribute(String namespaceUri,
                                    String attrName)

Sets the xml attribute which the input xml uses to indicate to a PluginCreateRule which class should be instantiated.

Example:

 setPluginClassAttribute( null, "class" );
 

will allow this in the input xml:

  <root>
    <some-plugin class="com.acme.widget"> ......
 

instead of the default syntax:

  <root>
    <some-plugin plugin-class="com.acme.widget"> ......
 

This is particularly useful if the input xml document is not in English.

Note that the xml attributes used by PluginDeclarationRules are not affected by this method.

Parameters:

namespaceUri - is the namespace uri that the specified attribute is in. If the attribute is in no namespace, then this should be null. Note that if a namespace is used, the attrName value should not contain any kind of namespace-prefix. Note also that if you are using a non-namespace-aware parser, this parameter must be null.

attrName - is the attribute whose value contains the name of the class to be instantiated.

setPluginIdAttribute

public void setPluginIdAttribute(String namespaceUri,
                                 String attrName)

Sets the xml attribute which the input xml uses to indicate to a PluginCreateRule which plugin declaration is being referenced.

Example:

 setPluginIdAttribute( null, "id" );
 

will allow this in the input xml:

  <root>
    <some-plugin id="widget"> ......
 

rather than the default behaviour:

  <root>
    <some-plugin plugin-id="widget"> ......
 

This is particularly useful if the input xml document is not in English.

Note that the xml attributes used by PluginDeclarationRules are not affected by this method.

Parameters:

namespaceUri - is the namespace uri that the specified attribute is in. If the attribute is in no namespace, then this should be null. Note that if a namespace is used, the attrName value should not contain any kind of namespace-prefix. Note also that if you are using a non-namespace-aware parser, this parameter must be null.

attrName - is the attribute whose value contains the id of the plugin declaration to be used when instantiating an object.

getPluginClassAttrNs

public String getPluginClassAttrNs()

Get the namespace for the xml attribute which indicates to a PluginCreateRule which class is to be plugged in.

May be null (in fact, normally will be).

Returns:

the namespace for the xml attribute which indicates which class is to be plugged in.

getPluginClassAttr

public String getPluginClassAttr()

Get the namespace for the xml attribute which indicates to a PluginCreateRule which class is to be plugged in.

The return value is never null.

Returns:

the namespace for the xml attribute which indicates which class is to be plugged in.

getPluginIdAttrNs

public String getPluginIdAttrNs()

Get the namespace for the xml attribute which indicates to a PluginCreateRule which previous plugin declaration should be used.

May be null (in fact, normally will be).

Returns:

the namespace for the xml attribute which indicates which previous plugin declaration should be used.

getPluginIdAttr

public String getPluginIdAttr()

Get the namespace for the xml attribute which indicates to a PluginCreateRule which previous plugin declaration should be used.

The return value is never null.

Returns:

the namespace for the xml attribute which indicates which previous plugin declaration should be used.