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https://issues.apache.org/jira/browse/TIKA-4831?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=18108773#comment-18108773
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ASF GitHub Bot commented on TIKA-4831:
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dschmidt commented on PR #3044:
URL: https://github.com/apache/tika/pull/3044#issuecomment-5437621126
Real fixtures are in now: a worksheet written by GeoGebra Classic 5.4 (three
text objects, one of them the dynamic `"Hypotenuse c = " + c` kind that item 4
was about) and a two-page Notes file with thumbnails and an inserted picture.
Both were produced with the GeoGebra web apps, so no licensing strings
attached. They replace the synthetic .ggb in TestContainerAwareDetector and get
their own parser tests.
> Add content-based detection and a parser for GeoGebra files (ggb, ggs, ggt)
> ---------------------------------------------------------------------------
>
> Key: TIKA-4831
> URL: https://issues.apache.org/jira/browse/TIKA-4831
> Project: Tika
> Issue Type: New Feature
> Reporter: Dominik Schmidt
> Priority: Major
>
> GeoGebra files are currently only recognized by file extension. The mime
> registry has glob-only entries for {{application/vnd.geogebra.file}}
> ({{*.ggb}})
> and {{application/vnd.geogebra.tool}} ({{*.ggt}}), but both formats are zip
> containers and the entries are not declared as sub-classes of
> {{application/zip}}. As a result, as soon as content is available, magic
> detection returns {{application/zip}} and the filename hint is discarded in
> {{MimeTypes.applyHint()}} - even when the resource name is known. Content-only
> detection (no filename) has no way to identify the formats at all, and the
> newer GeoGebra formats {{*.ggs}} (Notes/Slides) and {{*.ggp}} (Pinboard) are
> missing from the registry entirely.
> There is also no parser for any of the GeoGebra formats: files fall through to
> the generic {{PackageParser}}, which extracts the zip entries but produces no
> document metadata and no usable text (the {{geogebra.xml}} construction is
> emitted as raw XML through the XML parser).
> Proposed improvement:
> * mime registry: declare {{application/vnd.geogebra.file}} and
> {{application/vnd.geogebra.tool}} as {{sub-class-of application/zip}}; add
> {{application/vnd.geogebra.slides}} ({{*.ggs}}, zip-based) and
> {{application/vnd.geogebra.pinboard}} ({{*.ggp}}, JSON-based)
> * a {{ZipContainerDetector}} that identifies the formats without a filename by
> their well-known entries: {{geogebra.xml}} (worksheet), {{structure.json}}
> plus {{_slideN/geogebra.xml}} (Notes/Slides), {{geogebra_macro.xml}} (tool);
> a worksheet with macros contains both {{geogebra.xml}} and
> {{geogebra_macro.xml}}, so the decision must be made after all entry names
> have been seen
> * a {{GeoGebraParser}} for ggb/ggs/ggt that extracts the construction metadata
> (title, author, date) and application name/version, emits the user-visible
> text (text objects, rich-text notes, captions, macro names/help) as XHTML,
> and emits the embedded {{geogebra_thumbnail.png}} (root, or the first
> slide's
> for Notes/Slides) as an embedded document marked
> {{embeddedResourceType=THUMBNAIL}}, following the existing convention in the
> OOXML, ODF and iWork parsers, so downstream consumers of {{/unpack/all}}
> sidecars can identify the preview image
> Use case: file sync/share servers (e.g. OpenCloud) use Tika for content
> extraction and for serving embedded preview images; with the THUMBNAIL marker
> they can select the representative preview of a GeoGebra file the same way as
> for Office documents.
> Pull request to follow.
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