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Fedora Repository Views

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But the angle one views the repository might also affect the number of entries seen. The above, recursive approach will always lead to one entry per data object. The remedy for this is to mark some classes as Entries for a certain view angle. This means that to compute the records for a given view angle, the view of all objects of a class that is an Entry should be computed. This is the view of the repository.

Fedora Implementation 

This section describes how the above could be implemented in Fedora. 

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Object State Changed

Code Block
languagejava
objectModifiedvoid objectStateModified(String pid, Date date, String state) {
 
	//Find the DomsObject rows that regard this object.
	//There will be one per entry/viewAngle combination
	List<DomsObject> results = OBJECTS.list(objectPid=pid);


	//Find all Entries that include this object
	for (DomsObject result : results) {
    	if (!result.getEntryPid().equals(pid)) {
        	//Mark them as updated
	        updateEntry(result.getEntryPid(),
    	                      state,
        	                  result.getViewAngle(),
            	              date);
	    }
	}


	// Find view Info for this object
	List<ViewInfo> viewInfoList = fedora.getViewInfo(pid, date);
	for (ViewInfo viewInfo : viewInfoList) {
    	//If it is an entry object, set it in the ENTRIES table
	    if (viewInfo.isEntry()) {
    	    updateEntry(pid, state, viewInfo.getViewAngle(), date);
	        updateDomsObjects(pid, pid, viewInfo.getViewAngle());
    	}
	}
}
private
void updateEntry(String entryPid, String state, String viewAngle, Date date) {
    //Find the Entry objects that fulfill these restrictions
    List<Entry> results = ENTRIES.list(entrypid,state,viewangle)

    //There might be no Entry, but if we are here, we know that an entry should exist, so create it.
    if (results.size() == 0) {
		ENTRIES.insert(new Entry(entryPid, viewAngle, state, date));
    } else {
        for (Entry result : results) {
            //Or there might have been some results
    
	        //Is this entry older than the current change?
            if (result.getDateForChange().getTime() < date.getTime()) {
                result.setDateForChange(date);
                result.setEntryPid(entryPid);
                result.setState(state);
                result.setViewAngle(viewAngle);
            }
            //Save the entry
            ENTRIES.update(result);
        }
    }
}
 
void updateDomsObjects(String objectPid, String entryPid, String viewAngle) {
	list<DomsObject> results = OBJECTS.list(objectPid,entryPid,viewAngle)
    if (results.size() == 0) {
        OBJECTS.insert(new DomsObject(objectPid, entryPid, viewAngle));
    }
}

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