Documentation/Fields

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Interoperability discussion:

There is one huge, glaring difference in Fields between LO and MS Word. Word does not automatically update the content of a field when the variable changes, but LO does.

NOTE: This is a work in progress. I'm trying to learn about fields and am noting my observations as I go along.


Fields in MS Word:

  • do not automatically update when the variable changes.
    • exception: PRINTDATE
    • exception: SAVEDATE updates ONLY at FILEOPEN (yet LASTSAVEDBY never auto-updates)
    • updated manually when the user selects a field and presses F9
    • to update all fields, the Internet suggests Ctrl-A to select all, and then press F9
  • can be edited by hand
  • generally do not have the UI option to be "fixed" or unchangeable (although Ctrl-F11 will set fldLock'd for any field I expect)
    • fldLocked fields can be updated by editing them and pressing OK


Fields in LO:

  • always update automatically (unless FIXED)
    • LO probably needs to be extended to allow the field an option to manually updated. So a bit like "fixed"
  • cannot be edited by hand when tied to a variable
  • FIXED date format must be recognized as a valid date in order to work
  • always can be marked as "fixed"
    • this is a way to preserve/import a field whose displayString doesn't match the variableValue
      • doing this will interfere with fldLock - which is rarely used since it is not easily UI accessible.


Why not just import as plain text instead of a field?

  • data loss in MS Word primarily


Things to watch out for during import:

  • always make sure export also works (for all formats). DOCX export in particular is just bad/wrong, while RTF just seems to always work.
  • import only works if the variableValue matches the displayString. If not, either mark as fixed, or treat as plain text instead.
    • there are lots of reasons why it might not match. MS Word allows a lot of special formatting (upper, lower, title, sentence-case), or the user could have just typed something else.


Things to watch out for during export:

  • make sure the MS Format doesn't support "locked" for that field type. If it does, then import has to handle that carefully.
    • Date/Time are there for sure. See Read_F_DateTime.


Things to figure out:

  • what is it with special characters like extra nulls etc. For example
   lcl_GetExpandedField(const SwField &rField) {
       //replace LF 0x0A with VT 0x0B
       return rField.ExpandField(true, nullptr).replace(0x0A, 0x0B);