Export translations that were changed in Launchpad

Implementation of the blueprint export-changed-in-launchpad.

Analysis of existing code

There is already code to

• Export files in PO format
• Select only those files that where changed in Launchpad (for display)

Export of a PO file

Call Hierarchy

The cron script is doing this:

• scripts.po_export_py.process_request:161 -> ITranslationExporter.getExporterProducingTargetFileFormat

  • pofile.zcml.subscriber:30 -> GettextPOExporter

  scripts.po_export_py.process_request:183 -> generate_translatoinfiledata

  • scripts.po_export_py.generate_translatoinfiledata:149 -> ITranslationFileData(IPOFile)

    • pofile.zcml.adapter:23 -> POFileToTranslationFileDataAdapter

      • database.pofile.py.POFileToTranslationFileDataAdapter.init:1277 -> _getMessages

        • database.pofile.py.POFileToTranslationFileDataAdapter._getMessages:1359 -> get_pofile_rows

          • database.vpoexport.py.VPOExportSet.get_pofile_rows:117 -> _select

            • database.vpoexport.py.VPOExportSet.get_pofile_rows:94 -> cur.execute database.vpoexport.py.VPOExportSet.get_pofile_rows:97 -> yield VPOExport

  scripts.po_export_py.process_request:182 -> exportTranslationFiles

  • translationformat.gettext_po_exporter.exportTranslationFiles

Issues

• The export uses the POExport view and selects the relevant messages from in get_pofile_rows. This select could be adapted to retrieve only the changed rows.
• The ITranslationFormatExporter is selected using the file format but this has no influence on generate_translationfiledata. This information would have to be passed down to get_pofile_rows.
• A seperate ITranslationFormatExporter is needed for this because the file will ommit the header, and add a warning, too. This should share code with the existing POFormatExporter.

Selection of changed translations

POFile has a method getPOTMsgSetChangedInLaunchpad that returns a POTMsgSet with the relevant messages. This could be adapted to ITranslationFileData like POFile itself but then it would not use the export view. What is the difference between the view and the query in this method?

Planing code changes

List of files to touch (incomplete).

• templates/pofile-export.pt
  • Add controls
• database/vpoexport.py
  • extend where clause in get_pofile_rows
  • add filter parameter to get_pofile_rows
• database/pofile.py
  • use getPOTMsgSetChangedInLaunchpad
  • remove XXX
  • POFileToTranslationFileDataAdapter._getMessages
• interfaces/translationexporter.py
  • remove XXX in ITranslationFormatExporter
  • add filter parameter to ITranslationFormatExporter.exportTranslationFiles?
• interfaces/translationfileformat.py
  • add Enum PO_LPCHANGED
• translationformat/gettext_po_exporter.py
  • move tests from docstring to doctest?
  • create a new exporter based on GettextPOExporter or create new base for both
• zcml/translationexport.zcml
  • Register new exporter as subscriber