org.apache.commons.digester.plugins: public class: PluginContext

org.apache.commons.digester.plugins
public class: PluginContext [javadoc | source]

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

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 -

Field Summary
public final String	DFLT_PLUGIN_CLASS_ATTR_NS
public final String	DFLT_PLUGIN_CLASS_ATTR
public final String	DFLT_PLUGIN_ID_ATTR_NS
public final String	DFLT_PLUGIN_ID_ATTR

Constructor:
public PluginContext() { //------------------- constructors --------------------------------------- }

Method from org.apache.commons.digester.plugins.PluginContext Summary:
getPluginClassAttr, getPluginClassAttrNs, getPluginIdAttr, getPluginIdAttrNs, getRuleFinders, setPluginClassAttribute, setPluginIdAttribute, setRuleFinders

Methods from java.lang.Object:
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method from org.apache.commons.digester.plugins.PluginContext Detail:
public String getPluginClassAttr() { return pluginClassAttr; } 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.
public String getPluginClassAttrNs() { return pluginClassAttrNs; } 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).
public String getPluginIdAttr() { return pluginIdAttr; } 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.
public String getPluginIdAttrNs() { return pluginIdAttrNs; } 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).
public List getRuleFinders() { if (ruleFinders == null) { // when processing a plugin declaration, attempts are made to // find custom rules in the order in which the Finder objects // are added below. However this list can be modified ruleFinders = new LinkedList(); ruleFinders.add(new FinderFromFile()); ruleFinders.add(new FinderFromResource()); ruleFinders.add(new FinderFromClass()); ruleFinders.add(new FinderFromMethod()); ruleFinders.add(new FinderFromDfltMethod()); ruleFinders.add(new FinderFromDfltClass()); ruleFinders.add(new FinderFromDfltResource()); ruleFinders.add(new FinderFromDfltResource(".xml")); ruleFinders.add(new FinderSetProperties()); } return ruleFinders; } 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.
public void setPluginClassAttribute(String namespaceUri, String attrName) { pluginClassAttrNs = namespaceUri; pluginClassAttr = 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.
public void setPluginIdAttribute(String namespaceUri, String attrName) { pluginIdAttrNs = namespaceUri; pluginIdAttr = 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.
public void setRuleFinders(List ruleFinders) { this.ruleFinders = 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.

Method from org.apache.commons.digester.plugins.PluginContext Detail:

 public String getPluginClassAttr() {
        return pluginClassAttr;
}

The return value is never null.

 public String getPluginClassAttrNs() {
        return pluginClassAttrNs;
}

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

 public String getPluginIdAttr() {
        return pluginIdAttr;
}

The return value is never null.

 public String getPluginIdAttrNs() {
        return pluginIdAttrNs;
}

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

 public List getRuleFinders() {
        if (ruleFinders == null) {
            // when processing a plugin declaration, attempts are made to
            // find custom rules in the order in which the Finder objects
            // are added below. However this list can be modified
            ruleFinders = new LinkedList();
            ruleFinders.add(new FinderFromFile());
            ruleFinders.add(new FinderFromResource());
            ruleFinders.add(new FinderFromClass());
            ruleFinders.add(new FinderFromMethod());
            ruleFinders.add(new FinderFromDfltMethod());
            ruleFinders.add(new FinderFromDfltClass());
            ruleFinders.add(new FinderFromDfltResource());
            ruleFinders.add(new FinderFromDfltResource(".xml"));
            ruleFinders.add(new FinderSetProperties());
        }
        return ruleFinders;
}

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

 public  void setPluginClassAttribute(String namespaceUri,
    String attrName) {
        pluginClassAttrNs = namespaceUri;
        pluginClassAttr = attrName;
}

Example:

setPluginClassAttribute(null, "class");

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

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

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

 public  void setPluginIdAttribute(String namespaceUri,
    String attrName) {
        pluginIdAttrNs = namespaceUri;
        pluginIdAttr = attrName;
}

Example:

setPluginIdAttribute(null, "id");

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

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

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

 public  void setRuleFinders(List ruleFinders) {
        this.ruleFinders = ruleFinders;
}

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.