issue_comments

I made it work with openpyxl. I'm not sure all the code under @hookimpl is necessary... but it works :)

```python from datasette import hookimpl from datasette.utils.asgi import Response from openpyxl import Workbook from openpyxl.writer.excel import save_virtual_workbook from openpyxl.cell import WriteOnlyCell from openpyxl.styles import Alignment, Font, PatternFill from tempfile import NamedTemporaryFile

def render_spreadsheet(rows): wb = Workbook(write_only=True) ws = wb.create_sheet() ws = wb.active ws.title = "decp"

columns = rows[0].keys()
headers = []
for col in columns :
    c = WriteOnlyCell(ws, col)
    c.fill = PatternFill("solid", fgColor="DDEFFF")
    headers.append(c)
ws.append(headers)

for row in rows:
    wsRow = []
    for col in columns:
        c = WriteOnlyCell(ws, row[col])
        if col == "objet" :
            c.alignment = Alignment(wrapText = True)
        wsRow.append(c)
    ws.append(wsRow)

with NamedTemporaryFile() as tmp:
    wb.save(tmp.name)
    tmp.seek(0)
    return Response(
        tmp.read(),
        headers={
            'Content-Disposition': 'attachment; filename=decp.xlsx',
            'Content-type': 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet'
        }
    )

@hookimpl def register_output_renderer(): return {"extension": "xlsx", "render": render_spreadsheet, "can_render": lambda: False}

```

The key part was to find the right function to wrap the spreadsheet object wb. NamedTemporaryFile() did it!

I'll update this issue when the plugin is packaged and ready for broader use.

Apparently, beside a string, Reponse could also work with bytes.

I found a neat tutorial to set up gettext with jinja2: http://siongui.github.io/2016/01/17/i18n-python-web-application-by-gettext-jinja2/

I have the feeling that the text visible to users is 95% present in template files (datasette/templates). The python code mainly contains error messages.

In the current situation, the best way to provide a localized frontend is to translate the templates and configure datasette to use them. I think I'm going to do it for French.

If we want localization to be better integrated, for the python code, I think gettext is the way to go. The .po can be translated in user-friendly tools such as Transifex and Crowdin.

For the templates, I'm not sure how we could do it cleanly and easy to maintain. Maybe the tools above could parse HTML and detect the strings to be translated.

In any case, localization implementing l10n is just the first step: a continuous process must be setup to maintain the translations and produce new ones while datasette keeps getting new features.