org.activemath.abstractcontent
Class CascadingMBaseRef

java.lang.Object
  org.activemath.abstractcontent.CascadingMBaseRef

All Implemented Interfaces:

MBaseRef

public class CascadingMBaseRef
extends Object
implements MBaseRef

A class to wrap several MBaseRef within a cascaded order, each shadowing the next.

This class is based on the ability for an MBaseRef to say when it contains an ID, currently, this is based on the use of MBaseRef.getCanonicalID(org.activemath.abstractcontent.MBaseID): before each request, this object goes along the list of MBaseRefs and asks it wether it contains the given ID, if yes, the indicated request is sent to this MBaseRef.

For the search facilities which involve returning all relations, all the MBaseRefs are used. This means that some of these requests may actually return double values.

This allows an author, for example, to have its own OmdocJdomMBase, for example, with a small content in it, the content it is editing, and relay the rest of the request to a larger container. It also allows authors to shadow an existing content by returning, from its own MBase, the content of IDs it wishes to overwrite.

FUTURE: this class will, in the future, be an extension of MultiMBase so as to target better the identification of the appropriate MBaseRef using collection names.

Version:

Nested Class Summary

Nested classes/interfaces inherited from interface org.activemath.abstractcontent.MBaseRef

MBaseRef.Dependency, MBaseRef.Relation

Constructor Summary

CascadingMBaseRef(List mbases)

CascadingMBaseRef(Subconfiguration config)
Uses the mbases.xxx children to create each MBases, which are sorted in alphabetical order.

Method Summary

void	assertItsUp() Asserts that the database connection is up and running.
protected boolean	containsID(MBaseRef ref, MBaseID id) Invokes MBaseRef.getCanonicalID(org.activemath.abstractcontent.MBaseID) on the indicated MBaseRef returning true if no exception was thrown or false if one was.
String	getAttribute(MBaseID id, String attributeName) Returns the MBaseRef.getAttribute(org.activemath.abstractcontent.MBaseID, java.lang.String) of the first MBaseRef that contains the ID.
MBaseID	getCanonicalID(MBaseID id) Returns a fully-qualified unique ID that enables collections of IDs to behave properly.
OJElement	getChildren(MBaseID id, String xPathReducedExpression) Returns the content of the named descendant of the element of given ID.
Collection	getCollectionsProvided() returns a Collection (object) with the collections (content blocks) provided by this MBaseRef
Map	getCommonName(MBaseID id) Returns the names of this element which is fetched either from the <metadata><dc:Title> descendant or from the <commonname> elements.
OJElement	getCompleteDCMetadata(MBaseID id) Returns a metadata element with only Dublin-Core children including inherited ones from their parents.
Iterator	getDefinitions(MBaseID id, Collection collections) For a symbol, this method returns the IDs of all definitions.
Iterator	getDependencies(MBaseID id) Gets an Iterator of MBaseRef.Dependency relations with all relations that stem from this element.
OJElement	getFormalContent(MBaseID id) From any ID this method returns the content of the FMP element.
MBaseID[]	getForWhat(MBaseID id) Returns the ID contained in the attribute for
Iterator	getIncomingRelations(MBaseID id, Collection collections) Returns an iterator of MBaseRef.Relations objects describing the relations that point to this item.
Iterator	getItemsModifiedSince(Date date)
Date	getLastModified(Collection ids) Returns the latest modification dates of the elements whose IDs are given.
MBaseRef	getMBaseContaining(MBaseID id) Goes through the list of MBaseRefs invoking, on each, containsID(MBaseRef,MBaseID) and returning the first that responds true.
MBaseRef	getMBaseContaining(String collName)
protected MBaseRef	getMBaseContainingOrThrow(MBaseID id) The same as getMBaseContaining(org.activemath.abstractcontent.MBaseID) but throws MBaseItemNotFoundException instead of returning null.
List	getMBaseList()
OJElement	getMetadata(MBaseID id) Returns the contents of the <metdata> child of this element.
Iterator	getOutgoingRelations(MBaseID id) Returns an iterator of MBaseRef.Relations objects describing the relations that point from this item.
Iterator	getProofs(MBaseID id, Collection collections) For an assertion, this method returns the IDs of all of its proofs.
Iterator	getRelated(MBaseID id, Collection collections) Goes through all MBaseRefs amalgamating all the Iterators provided.
OJDocument	getStructuredListOfConcepts(Collection collections) This expensive operation walks the complete XML structure of one single collection stored in the server and creates a theory element for each theory then a concept element for each of the concepts (symbol, definition, assertion, proof, methods).
Map	getTagFreeCommonName(MBaseID id) Returns the titles without any tags, just extracting the text or partially rendering it.
List	getTextualContent(MBaseID id) From any ID this method returns the row of CMP elements' contents.
MBaseID	getTheory(MBaseID id) Returns the ID of the closest parent (including the element itself) that either has a theory attribute or is a theory element or null if there is no such parent.
String	getTypeString(MBaseID id) Returns the name of the element whose ID is given.
Iterator	iterateOverIterators(Iterator itsOfIt)
Iterator	listItems(Collection collections, String type) Lists all the items being children of the element of the indicated ID.
Iterator	listItems(MBaseID id) Lists all the items being children of the element of the indicated ID.
Iterator	listTheories(Collection collections) Lists all the IDs of the theory elements contained in the indicated collections .
Iterator	searchText(String textToSearch, Collection collections) Searches the union of all text elements, but not the attributes, for the given substring in a case-sensistive manner.

Methods inherited from class java.lang.Object

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

Constructor Detail

CascadingMBaseRef

public CascadingMBaseRef(List mbases)

Parameters:

mbases - a List of MBaseRefs to be used.

CascadingMBaseRef

public CascadingMBaseRef(Subconfiguration config)
                  throws Exception

Uses the mbases.xxx children to create each MBases, which are sorted in alphabetical order. The MBaseRefs are created using ConfiguredObjectMaker which is expected to be provided by the sub-configuration.

Parameters:

config - The subconfiguration to extract the mbases. from

Throws:

Exception - if anything happens

Method Detail

getMBaseList

public List getMBaseList()

Returns:

the list of MBaseRef that is being queried.

getMBaseContaining

public MBaseRef getMBaseContaining(MBaseID id)
                            throws MBaseException

Goes through the list of MBaseRefs invoking, on each, containsID(MBaseRef,MBaseID) and returning the first that responds true.

Parameters:

id - The ID to search for

Returns:

the first MBaseRef in the list that responds positively to containsID(MBaseRef,MBaseID).

Throws:

MBaseException - if any of the MBaseRefs throw it

MBaseItemNotFoundException - never, returns null instead

getMBaseContaining

public MBaseRef getMBaseContaining(String collName)
                            throws MBaseException

Throws:

MBaseException

getDependencies

public Iterator getDependencies(MBaseID id)
                         throws MBaseException

Description copied from interface: MBaseRef

Gets an Iterator of MBaseRef.Dependency relations with all relations that stem from this element. Relations are considered the same as dependencies in this class. They are of many types as described in the MBaseRef.Dependency class. Use MBaseRef.getDependencies(org.activemath.abstractcontent.MBaseID) to read the list of relations that stem from another element but target this element.

Note that the server implementation is not required to return all these types only the content of the <depends-on> elements are required to be returned.

Specified by:

getDependencies in interface MBaseRef

Parameters:

id - The ID of the element whose dependencies are wished

Returns:

the result MBaseRef.getDependencies(org.activemath.abstractcontent.MBaseID) on the first MBaseRef that contains the indicated ID.

Throws:

MBaseException - If any of the mbases throws an exception different than MBaseItemNotFoundException

getRelated

public Iterator getRelated(MBaseID id,
                           Collection collections)
                    throws MBaseException

Goes through all MBaseRefs amalgamating all the Iterators provided. TODO: This method should be enhanced to avoid providing double entries which ican happen when in the scenario of an overwriting (i.e. when an item is present in two MBases.

Specified by:

getRelated in interface MBaseRef

Parameters:

id - Missing description of Parameter

collections - Missing description of Parameter

Returns:

the amalgamation of the Iterator objects returned by each of the members of the list.

Throws:

MBaseException - Missing description of Exception

getChildren

public OJElement getChildren(MBaseID id,
                             String xPathReducedExpression)
                      throws MBaseException

Description copied from interface: MBaseRef

Returns the content of the named descendant of the element of given ID. The descendant are found using the xPathReducedExpression parameter which aims at imitating an XPath expression except it only accepts the ., / and named elements.

This walks the tree of descendants, taking children everytime a /elementName is found in the xPathReducedExpression and returns the content of the end child.

Such a method might be a warmer future for all requests, including getDependencies, getMetaData and getCommonName.

Specified by:

getChildren in interface MBaseRef

Parameters:

id - the MBaseID to get the children of

xPathReducedExpression - as described above

Returns:

the OJElement thus crafted

Throws:

MBaseException - if something fails

getAttribute

public String getAttribute(MBaseID id,
                           String attributeName)
                    throws MBaseException

Returns the MBaseRef.getAttribute(org.activemath.abstractcontent.MBaseID, java.lang.String) of the first MBaseRef that contains the ID.

Specified by:

getAttribute in interface MBaseRef

Parameters:

id - Missing description of Parameter

attributeName - Missing description of Parameter

Returns:

Missing description of return The attribute value

Throws:

MBaseException - Missing description of Exception

getDefinitions

public Iterator getDefinitions(MBaseID id,
                               Collection collections)
                        throws MBaseException

Description copied from interface: MBaseRef

For a symbol, this method returns the IDs of all definitions.

Specified by:

getDefinitions in interface MBaseRef

Parameters:

id - id the id of the symbol whose definitions are looked at

collections - collections the name of the collections to be searched

Returns:

null for non-symbol elements or if no definition is found.

Throws:

MBaseException - if something's wrong.

getProofs

public Iterator getProofs(MBaseID id,
                          Collection collections)
                   throws MBaseException

Description copied from interface: MBaseRef

For an assertion, this method returns the IDs of all of its proofs.

Specified by:

getProofs in interface MBaseRef

Parameters:

id - MBaseID denoting the assertion whose proofs are to be searched

collections - Collection of (content) collections to search in

Returns:

an Iterator with the proofs, that is empty for non-assertion elements or if no proof is found.

Throws:

MBaseException - if something's wrong.

getTextualContent

public List getTextualContent(MBaseID id)
                       throws MBaseException

Description copied from interface: MBaseRef

From any ID this method returns the row of CMP elements' contents. The server is supposed to "resolve" the occurrences of <OMS> who are "referenced" by means of the xref attribute.

Specified by:

getTextualContent in interface MBaseRef

Parameters:

id - The ID of the item whose CMPs are to be returned

Returns:

A list of OJElements being the CMP nodes

Throws:

MBaseException - if something fails

getFormalContent

public OJElement getFormalContent(MBaseID id)
                           throws MBaseException

Description copied from interface: MBaseRef

From any ID this method returns the content of the FMP element. The server is supposed to "resolve" the occurrences of <OMS> who are "referenced" by means of the xref attribute.

Specified by:

getFormalContent in interface MBaseRef

Parameters:

id - The ID whose FMP child is to be fetched

Returns:

a the OJElement representing the <FMP> or null if there is no <FMP> content behind the ID

Throws:

MBaseException - if something fails

getMetadata

public OJElement getMetadata(MBaseID id)
                      throws MBaseException

Description copied from interface: MBaseRef

Returns the contents of the <metdata> child of this element. This does not apply the inheritance principles of Dublin-Core metadata (as described in OMDoc 1.1 specifications), please use MBaseRef.getCompleteDCMetadata(org.activemath.abstractcontent.MBaseID) for this task.

Specified by:

getMetadata in interface MBaseRef

Parameters:

id - The ID of the item whose metadata element is to be fetched.

Returns:

The metadata OJElement

Throws:

MBaseException - if something fails

getCompleteDCMetadata

public OJElement getCompleteDCMetadata(MBaseID id)
                                throws MBaseException

Description copied from interface: MBaseRef

Returns a metadata element with only Dublin-Core children including inherited ones from their parents. The inheritance is described in OMDoc 1.1 specifications (i.e. added values with children taking precedence when a triple (language, element-name, role) also exists.

This allows most of the copyright informations to be stored in the metadata element of the OMDoc while additions can override or enrich these values.

Specified by:

getCompleteDCMetadata in interface MBaseRef

Parameters:

id - the ID of the item whose metadata is to be fetched

Returns:

the completed OJElement metadata node

Throws:

MBaseException - If anything happens

getTheory

public MBaseID getTheory(MBaseID id)
                  throws MBaseException

Description copied from interface: MBaseRef

Returns the ID of the closest parent (including the element itself) that either has a theory attribute or is a theory element or null if there is no such parent.

Specified by:

getTheory in interface MBaseRef

Parameters:

id - The item whose theory is to be found

Returns:

The MBaseID of the related theory element

Throws:

MBaseException - if something's wrong.

getCommonName

public Map getCommonName(MBaseID id)
                  throws MBaseException

Description copied from interface: MBaseRef

Returns the names of this element which is fetched either from the <metadata><dc:Title> descendant or from the <commonname> elements.

The table returned has, as keys, the language and as values the text of this common-name.

Specified by:

getCommonName in interface MBaseRef

Parameters:

id - The ID of the item whose titles are to be looked at.

Returns:

A Map of titles (keys String language}, values the String titles

Throws:

MBaseException - if something's wrong.

getTypeString

public String getTypeString(MBaseID id)
                     throws MBaseException

Description copied from interface: MBaseRef

Returns the name of the element whose ID is given.

Specified by:

getTypeString in interface MBaseRef

Parameters:

id - The ID of the element

Returns:

The (XML) element-name of this node

Throws:

MBaseException - if something's wrong.

getForWhat

public MBaseID[] getForWhat(MBaseID id)
                     throws MBaseException

Description copied from interface: MBaseRef

Returns the ID contained in the attribute for

Specified by:

getForWhat in interface MBaseRef

Parameters:

id - The ID of the item whose for attribute is to be looked at.

Returns:

The list of pointers interpreted from the pointer values in the for attribute of the element

Throws:

MBaseException - if something's wrong.

getStructuredListOfConcepts

public OJDocument getStructuredListOfConcepts(Collection collections)
                                       throws MBaseException

Description copied from interface: MBaseRef

This expensive operation walks the complete XML structure of one single collection stored in the server and creates a theory element for each theory then a concept element for each of the concepts (symbol, definition, assertion, proof, methods).

Specified by:

getStructuredListOfConcepts in interface MBaseRef

Parameters:

collections - strings with the name of the collection to search in

Returns:

an XML document structured by theory/element, or null, if there are no contents found

Throws:

MBaseException - if something fails

getCollectionsProvided

public Collection getCollectionsProvided()
                                  throws MBaseException

Description copied from interface: MBaseRef

returns a Collection (object) with the collections (content blocks) provided by this MBaseRef

Specified by:

getCollectionsProvided in interface MBaseRef

Returns:

Collection of Strings with the names of the provided collections

Throws:

MBaseException - If anything goes wrong (normally nothing is expected to go wrong here)

getCanonicalID

public MBaseID getCanonicalID(MBaseID id)
                       throws MBaseException

Description copied from interface: MBaseRef

Returns a fully-qualified unique ID that enables collections of IDs to behave properly. MBase engines may allow heuristics to interpret IDs, among others, to identify an item with an ID not containing a theory although the item is in a theory.

MBase engines should be consistent and never return more than one ID for a given item.

Specified by:

getCanonicalID in interface MBaseRef

Parameters:

id - the id that may be missing a theory or collection.

Returns:

a fully-qualified absolute ID pointing to the same element, or null if no such element was found.

Throws:

MBaseException - If anything goes wrong

searchText

public Iterator searchText(String textToSearch,
                           Collection collections)
                    throws MBaseException

Description copied from interface: MBaseRef

Searches the union of all text elements, but not the attributes, for the given substring in a case-sensistive manner. This operation is expected to be rather expensive.

Specified by:

searchText in interface MBaseRef

Parameters:

textToSearch - String containing the text to be searched

collections - Collection of collections (as Strings) to search in

Returns:

an Iterator of MBaseIDs that contain the string

Throws:

MBaseException - if something's wrong.

listItems

public Iterator listItems(MBaseID id)
                   throws MBaseException

Description copied from interface: MBaseRef

Lists all the items being children of the element of the indicated ID. Implementations are required to support this operation on omgroup and theory elements only.

Specified by:

listItems in interface MBaseRef

Parameters:

id - the ID of the omgroup, theory or other element

Returns:

An iterator of MBaseID objects

Throws:

MBaseException - If anything goes wrong

listTheories

public Iterator listTheories(Collection collections)
                      throws MBaseException

Description copied from interface: MBaseRef

Lists all the IDs of the theory elements contained in the indicated collections .

Specified by:

listTheories in interface MBaseRef

Parameters:

collections - the set of collection-names to be walked through for theories.

Returns:

an iterator over the list of IDs that are children

Throws:

MBaseException - If anything goes wrong

listItems

public Iterator listItems(Collection collections,
                          String type)

Description copied from interface: MBaseRef

Lists all the items being children of the element of the indicated ID. Implementations are required to support this operation on omgroup and theory elements only.

Specified by:

listItems in interface MBaseRef

Parameters:

collections - the possible collections where to search for the items of this type

type - the element name wished to be returne

Returns:

An iterator of MBaseID objects to the given elements

assertItsUp

public void assertItsUp()
                 throws MBaseException

Description copied from interface: MBaseRef

Asserts that the database connection is up and running. This may include a self test, so use only in code for test purposes (such as in an appropriate checker) or in non-looped code (once at startup or something).

Specified by:

assertItsUp in interface MBaseRef

Throws:

MBaseException - if something's wrong.

iterateOverIterators

public Iterator iterateOverIterators(Iterator itsOfIt)

getMBaseContainingOrThrow

protected MBaseRef getMBaseContainingOrThrow(MBaseID id)
                                      throws MBaseException

The same as getMBaseContaining(org.activemath.abstractcontent.MBaseID) but throws MBaseItemNotFoundException instead of returning null.

Parameters:

id - Missing description of Parameter

Returns:

Missing description of return The mBaseContainingOrThrow value

Throws:

MBaseException - Missing description of Exception

containsID

protected boolean containsID(MBaseRef ref,
                             MBaseID id)
                      throws MBaseException

Invokes MBaseRef.getCanonicalID(org.activemath.abstractcontent.MBaseID) on the indicated MBaseRef returning true if no exception was thrown or false if one was.

Note that if the provided MBaseRef is down this method simply returns false which may be a non-desired effect. To remedy this we should either have a method containsID in MBaseRef or have a better exception treatment with a qualified one being NoSuchIDException .

Parameters:

ref - the MBaseRef to call

id - the ID to request

Returns:

true if the MBaseRef contains the ID.

Throws:

MBaseException - if the MBaseRef had a trouble

MBaseItemNotFoundException - never (returns false instead

getLastModified

public Date getLastModified(Collection ids)
                     throws MBaseException

Description copied from interface: MBaseRef

Returns the latest modification dates of the elements whose IDs are given.

Specified by:

getLastModified in interface MBaseRef

Parameters:

ids - a list of MBaseIDs of items, theories, or Strings of collection name

Returns:

the latest modification date or, if unknown, the current date.

Throws:

MBaseException

getItemsModifiedSince

public Iterator getItemsModifiedSince(Date date)
                               throws MBaseException

Specified by:

getItemsModifiedSince in interface MBaseRef

Throws:

MBaseException

getTagFreeCommonName

public Map getTagFreeCommonName(MBaseID id)
                         throws MBaseException

Description copied from interface: MBaseRef

Returns the titles without any tags, just extracting the text or partially rendering it. Useful for string-only processors.

Specified by:

getTagFreeCommonName in interface MBaseRef

Parameters:

id - the item id.

Returns:

the map, associating a language string to a title-string.

Throws:

MBaseException

getIncomingRelations

public Iterator getIncomingRelations(MBaseID id,
                                     Collection collections)
                              throws MBaseException

Description copied from interface: MBaseRef

Returns an iterator of MBaseRef.Relations objects describing the relations that point to this item. If the item is a theory, the relations are the imports statements.

Specified by:

getIncomingRelations in interface MBaseRef

Parameters:

id - the id from which to see the relations

collections - from where should these relations be incoming

Returns:

an iterator of MBaseRef.Relations objects

Throws:

MBaseException - if anything

getOutgoingRelations

public Iterator getOutgoingRelations(MBaseID id)
                              throws MBaseException

Description copied from interface: MBaseRef

Returns an iterator of MBaseRef.Relations objects describing the relations that point from this item. If the item is a theory, the relations are the imports statements.

Specified by:

getOutgoingRelations in interface MBaseRef

Parameters:

id - the id from which to see the relations

Returns:

an iterator of MBaseRef.Relations objects

Throws:

MBaseException - if anything