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So essentially, it's a key/value store with children allowing you to store just about any piece of metadata.

Standard definitions

Common MetaModel Element Type definitions can be found on this page:

Standard MetaStore Element types

Java project

The Java project with the API and reference implementations is to be found over here:

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Self explanatory, to distinguish one Metastore from another.

  • getName()
  • getDescription()

Metastore password encoder

You can ask the MetaStore to give you the methods for encoding, decoding and verifying passwords or you can set your own methods (right after instantiating) with the following methods:

  • getTwoWayPasswordEncoder()
  • setTwoWayPasswordEncoder()

MetaStoreFactory

The basics

For your convenience we provided you with a MetaStoreFactory to facilitate the specific use-case of serializing POJO.
Consider a class annotated with @MetaStoreElementType and where private members are annotated with @MetaStoreAttribute 
  

Code Block

MyElement me = new MyElement( NAME, ATTR, ANOTHER, INT, LONG, BOOL, DATE ); 
MetaStoreFactory<MyElement> factory = new MetaStoreFactory<MyElement>( MyElement.class, metaStore, "custom" ); 

Now we can save the element in the metastore simply by calling: 

Code Block

factory.saveElement( me ); 

Loading the element by name from the metastore simply becomes: 

Code Block

MyElement verify = factory.loadElement( NAME );  

The unit test class which demos this behavior is: MetaStoreFactoryTest 

The list of available methods in the factory is:

  • public T loadElement( String name ) throws MetaStoreException;
  • public void saveElement( T t ) throws MetaStoreException;
  • public List<T> getElements() throws MetaStoreException;
  • public void deleteElement( String name ) throws MetaStoreException;
  • public List<String> getElementNames() throws MetaStoreException;
  • public IMetaStoreElementType getElementType() throws MetaStoreException;
  • public T loadElement( String name ) throws MetaStoreException;
  •  

public void saveElement( T t ) throws MetaStoreException;
public List<T> getElements() throws MetaStoreException;
public void deleteElement( String name ) throws MetaStoreException;
public List<String> getElementNames() throws MetaStoreException;
public IMetaStoreElementType getElementType() throws MetaStoreException;

One factory calling another

If you have one element referencing another by name we can pass a factory to another factory to handle automatic persistence.

See for example the following :

Code Block

MetaStoreFactory<X> factoryX = new MetaStoreFactory<X>( X.class, metaStore, "pentaho" );
MetaStoreFactory<Y> factoryY = new MetaStoreFactory<Y>( Y.class, metaStore, "pentaho" );
factoryX.addNameFactory( X.FACTORY_Y, factoryY );

In this situation, if you call factoryX.saveElement() you will also persist any referenced elements of Y which are annotated as followed in class X:

Code Block

@MetaStoreAttribute( factoryNameKey = FACTORY_Y, factoryNameReference = true )
private List<Y> ys;

//and/or  

@MetaStoreAttribute( factoryNameKey = FACTORY_Y, factoryNameReference = true )
private Y y;

The factory is then also used when you are loading elements.

IMPORTANT NOTE: Do not rely on the referenced classes to be unique instances.  If you want that goal, pass unique lists of elements to the factory using addNameList()

Optionally shared

Since you don't always want elements to be shared and visible for the whole metastore to see, you can make an element optionally shared and as such, optionally 'embedded' in the parent element attributes.
To do this, you simply tell the factory what the name is of the boolean field which expresses the fact that the element is shared.
For example, if you have a "shared" flag in class B:

Code Block

@MetaStoreAttribute
private boolean shared;

In this case you can reference this in class A as follows:

Code Block

@MetaStoreAttribute( factoryNameKey = FACTORY_B, factoryNameReference = true, factorySharedIndicatorName = "shared" )  
private B b;

The factory will then automatically determine to either create or update an element for B or embed it in the attributes of the A element.