MetadataExposureService (DSpace Kernel :: API and Implementation 7.6.1 API)

All Known Implementing Classes:

MetadataExposureServiceImpl
```
public interface MetadataExposureService
```
Static utility class to manage configuration for exposure (hiding) of certain Item metadata fields. This class answers the question, "is the user allowed to see this metadata field?" Any external interface (UI, OAI-PMH, etc) that disseminates metadata should consult it before disseminating the value of a metadata field. Since the MetadataExposure.isHidden() method gets called in a lot of inner loops, it is important to implement it efficiently, in both time and memory utilization. It computes an answer without consuming ANY memory (e.g. it does not build any temporary Strings) and in close to constant time by use of hash tables. Although most sites will only hide a few fields, we can't predict what the usage will be so it's better to make it scalable. Algorithm is as follows: 1. If a Context is provided and it has a user who is Administrator, always grant access (return false). 2. Return true if field is on the hidden list, false otherwise. The internal maps are populated from DSpace Configuration at the first call, in case the properties are not available in the static context. Configuration Properties: ## hide a single metadata field #metadata.hide.SCHEMA.ELEMENT[.QUALIFIER] = true # example: dc.type metadata.hide.dc.type = true # example: dc.description.provenance metadata.hide.dc.description.provenance = true

Version:

$Revision: 3734 $

Author:

Larry Stone

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`boolean`	`isHidden(Context context, String schema, String element, String qualifier)`	Returns whether the given metadata field should be exposed (visible).

- Method Detail
  - isHidden
```
boolean isHidden(Context context,
                 String schema,
                 String element,
                 String qualifier)
          throws SQLException
```
    Returns whether the given metadata field should be exposed (visible). The metadata field is in the DSpace's DC notation: schema.element.qualifier
    
    Parameters:
    
    context - DSpace context
    
    schema - metadata field schema (namespace), e.g. "dc"
    
    element - metadata field element
    
    qualifier - metadata field qualifier
    
    Returns:
    
    true (hidden) or false (exposed)
    
    Throws:
    
    SQLException - if database error