plugins/org.eclipse.app4mc.amalthea.model.help/docu/dev_model_util_base.textile

h3. General Helper Classes

**Classes**

* "SearchElementsUtility":../help-javadoc/SearchElementsUtility.html
** This class contains utility methods which are used to search AMALTHEA model elements based on name (_also regex supported_), type. This utility internally builds a cache model and it is relatively fast for fetching the elements instead iterating through the model elements and finding the required ones.
* "DeleteElementsUtility":../help-javadoc/DeleteElementsUtility.html
** This class contains utility methods which are used to perform deletion of AMALTHEA model elements. These methods will be performance efficient while deleting huge number of objects
* "ModelStaticCacheBuilder":../help-javadoc/ModelStaticCacheBuilder.html
** This class is used to build a *static* cache for the entire AMALTHEA model. This cache can be used to fetch the model elements based on the name. *Note:* As this cache is *static*, if AMALTHEA model is changed, this cache should be deleted and re-created.  
* "ModelDynamicCacheBuilder":../help-javadoc/ModelDynamicCacheBuilder.html
** This class is used to build a *dynamic* cache for the entire AMALTHEA model. This cache can be used to fetch the model elements based on the name. *Note:* As this cache is *dynamic* -> it will be implicitly updated if AMALTHEA model is changed. If AMALTHEA model is changing frequently, this cache should not be used - as this can impact performance.

h4. How to use util API of these classes

* SearchElementsUtility

bc.. 
	Amalthea model=buildAmaltheaModel(<filePath>);
	SearchElementsUtility searchElementsUtility=new SearchElementsUtility(model);
	List<Label> elementsBasedOnName = searchElementsUtility.getElementsBasedOnName("d0",Label.class);
	List<Label> elementsBasedOnRegex = searchElementsUtility.getElementsBasedOnRegex("d\\d", Label.class);
	List<Label> elementsBasedOnType = searchElementsUtility.getElementsBasedOnType(Label.class);
	/* Supplying AMALTHEA model directly to the API */
	elementsBasedOnName=SearchElementsUtility.getElementsBasedOnName(model, "d0", Label.class);
p. 


* DeleteElementsUtility

bc.. 
	Amalthea model=buildAmaltheaModel(<filePath>);
	/* Deleting multiple model elements from AMALTHEA model */
	DeleteElementsUtility.deleteAll(model.getSwModel().getLabels(), model);
	org.eclipse.emf.ecore.resource.Resource resource=...
	/* Deleting multiple model elements which are belonging to a specific resource */
	DeleteElementsUtility.deleteAll(model.getSwModel().getLabels(), resource);
p. 


* ModelStaticCacheBuilder

bc.. 
	Amalthea model=buildAmaltheaModel(<filePath>);
	ModelStaticCacheBuilder modelStaticCacheBuilder =new ModelStaticCacheBuilder(model);
	List<Label>  elementsBasedOnName = modelStaticCacheBuilder.getElementsBasedOnName("d0", Label.class);
p. 


* ModelDynamicCacheBuilder

bc.. 
	Amalthea model=buildAmaltheaModel(<filePath>);
	ModelDynamicCacheBuilder modelDynamicCacheBuilder=new ModelDynamicCacheBuilder(model);
	List<Label>  elementsBasedOnName = modelDynamicCacheBuilder.getElementsBasedOnName("d0", Label.class);
	/* Deleting multiple model elements from AMALTHEA model */
	DeleteElementsUtility.deleteAll(model.getSwModel().getLabels(), model);
	// Adding new Label "L1" into AMALTHEA model
	elementsBasedOnName = modelDynamicCacheBuilder.getElementsBasedOnName("L1", Label.class);
	//In the above case, cache is automatically updated based on the model change 
	assertEquals("Cache is not updated ",1, elementsBasedOnName.size());
p.