[TIKA-930] Consolidation of Some Tika Core Properties

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.2
• Fix Version/s: 1.2
• Component/s: metadata
• Assignee: Unassigned
• Reporter: Ray Gauss II
• Created: 22/May/12 01:56
• Updated: 02/May/13 02:29
• Resolved: 03/Jul/12 03:24

Description

There are a few properties in TikaCoreProperties which overlap and I think we should minimize ambiguity by consolidating them into a single composite property with the clearest name, the most general specification referenced as its primary property, and the others and deprecated strings as its secondaries.

Here's the proposed pseudo-code for the changes:

Remove TikaCoreProperties.SUBJECT
TikaCoreProperties.KEYWORDS <- DublinCore.SUBJECT,

{ Office.KEYWORDS, MSOffice.KEYWORDS, Metadata.SUBJECT }

Remove TikaCoreProperties.DATE
TikaCoreProperties.CREATION_DATE <- DublinCore.DATE,

{ Office.CREATION_DATE, MSOffice.CREATION_DATE, Metadata.DATE }

Remove TikaCoreProperties.MODIFIED
TikaCoreProperties.SAVE_DATE <- DublinCore.MODIFIED,

{ Office.SAVE_DATE, MSOffice.LAST_SAVED, Metadata.MODIFIED, "Last-Modified" }

and an example of the Java changes:

TikaCoreProperties.java Before

    /**
     * @see DublinCore#SUBJECT
     */
    public static final Property SUBJECT = Property.composite(DublinCore.SUBJECT, 
            new Property[] { Property.internalText(Metadata.SUBJECT) });
      
    /**
     * @see Office#KEYWORDS
     */
    public static final Property KEYWORDS = Property.composite(Office.KEYWORDS,
            new Property[] { Property.internalTextBag(MSOffice.KEYWORDS) });

would become

TikaCoreProperties.java After

    /**
     * @see DublinCore#SUBJECT
     * @see Office#KEYWORDS
     */
    public static final Property KEYWORDS = Property.composite(DublinCore.SUBJECT,
            new Property[] { 
    		    Office.KEYWORDS, 
    		    Property.internalTextBag(MSOffice.KEYWORDS),
    		    Property.internalText(Metadata.SUBJECT)
    		});

Since this would require a bit of refactoring for parsers that use the properties being removed I thought it best to get some feedback before working up a full patch.

Does this seem like a reasonable approach?

Issue Links

• depends upon: TIKA-947 AbstractMetadataHandler addMetadata Does not Check Property.isMultiValuePermitted
• is related to: TIKA-962 Backwards Compatibility for Metadata.LAST_AUTHOR is Broken
• is related to: TIKA-963 Backwards Compatibility for Metadata.DATE is Incorrect